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Pierolapithecus and the functional morphology of Miocene ape hand phalanges: paleobiological and evolutionary implications
Abstract
The partial skeleton of Pierolapithecus, which provides the oldest unequivocal evidence of orthogrady, together with the recently described phalanges from Paşalar most likely attributable to Griphopithecus, provide a unique opportunity for understanding the changes in hand anatomy during the pronogrady/orthogrady transition in hominoid evolution. In this paper, we describe the Pierolapithecus hand phalanges and compare their morphology and proportions with those of other Miocene apes in order to make paleobiological inferences about locomotor evolution. In particular, we investigate the orthograde/pronograde evolutionary transition in order to test whether the acquisition of vertical climbing and suspension were decoupled during evolution. Our results indicate that the manual phalanges of Miocene apes are much more similar to one another than to living apes. In particular, Miocene apes retain primitive features related to powerful-grasping palmigrady on the basal portion, the shaft, and the trochlea of the proximal phalanges. These features suggest that above-branch quadrupedalism, inherited from stem hominoids, constituted a significant component of the locomotor repertories of different hominoid lineages at least until the late Miocene. Nonetheless, despite their striking morphological similarities, several Miocene apes do significantly differ in phalangeal curvature and/or elongation. Hispanopithecus most clearly departs by displaying markedly-curved and elongated phalanges, similar to those in the most suspensory of the extant apes (hylobatids and orangutans). This feature agrees with several others that indicate orang-like suspensory capabilities. The remaining Miocene apes, on the contrary, display low to moderate phalangeal curvature, and short to moderately-elongated phalanges, which are indicative of the lack of suspensory adaptations. As such, the transition from a pronograde towards an orthograde body plan, as far as this particular anatomical region is concerned, is reflected only in somewhat more elongated phalanges, which may be functionally related to enhanced vertical-climbing capabilities. Our results therefore agree with the view that hominoid locomotor evolution largely took place in a mosaic fashion: just as taillessness antedated the acquisition of an orthograde body plan, the emergence of the latter--being apparently related only to vertical climbing--also preceded the acquisition of suspensory adaptations, as well as the loss of primitively-retained, palmigrady-related features.
... Few Miocene hominoids have traits that reflect the undisputed use of hominoid-like suspensory locomotion (19), with the potential exception of Hispanopithecus laietanus (18) and Danuvius guggenmosi (20). For example, the Miocene fossil hominoids Sivapithecus and Pierolapithecus have dorsally oriented articular surfaces of their manual proximal phalanges, indicating the habitual use of extended metacarpophalangeal (MCP) joints in palmigrade quadrupedalism (21). ...
... Metacarpal length has mechanical consequences in the context of varied positional repertoires, hand postures, and substrate preferences. Nonpollical metacarpal length has been argued to be a correlate of suspensory positional behaviors (2,21). The presence of shorter metacarpals relative to support diameters may cause increases in wrist flexion during suspension (31). ...
... (IP3) using digital calipers: maximum length (L), mediolateral breadth (BML) and dorsopalmar depth of the base (BDP), midshaft (MSML and MSDP), and head/trochlea (HML, HDP, TML, and TDP) (21,36). The phalanges of the third digit were identified on the basis of their interdigital size and shape characteristics (e.g., length, robusticity, torsion, and asymmetries). ...
The morphology and positional behavior of the last common ancestor of humans and chimpanzees are critical for understanding the evolution of bipedalism. Early 20th century anatomical research supported the view that humans evolved from a suspensory ancestor bearing some resemblance to apes. However, the hand of the 4.4-million-year-old hominin Ardipithecus ramidus purportedly provides evidence that the hominin hand was derived from a more generalized form. Here, we use morphometric and phylogenetic comparative methods to show that Ardipithecus retains suspensory adapted hand morphologies shared with chimpanzees and bonobos. We identify an evolutionary shift in hand morphology between Ardipithecus and Australopithecus that renews questions about the coevolution of hominin manipulative capabilities and obligate bipedalism initially proposed by Darwin. Overall, our results suggest that early hominins evolved from an ancestor with a varied positional repertoire including suspension and vertical climbing, directly affecting the viable range of hypotheses for the origin of our lineage.
... Comparison: In contrast to extant great apes, which have proximally facing, round and deep patelliform metacarpo-phalangeal joint surfaces, the proximal articulation in Danuvius is nonpatelliform and slightly convex dorsally, significantly flattened dorsopalmary (8.5 mm height, 11.7 mm wide on PP2) and extend slightly onto the dorsal aspect of the shaft (Fig. 2b). The basal tubercles in extant African apes can be large as well (contra 14,15 ), but in contrast to Danuvius they are more knob-like and palmary tapered. The tubercles are generally reduced in Pongo. ...
... The tubercles are generally reduced in Pongo. In these features, Danuvius more closely resembles the Miocene apes Pierolapithecus, Hispanopithecus, Sivapithecus, Griphopithecus (Paşalar) ( 14,(16)(17)(18) ) and cercopithecides ( 16 and authors observations). With its more generalized hand morphology, Danuvius most likely usedpalmigrade hand postures on the ground, but with minimal hyperextension at the metacarpo-phalangeal joint, in contrast to knuckle-or fist-walking of extant great apes 14 . ...
... In these features, Danuvius more closely resembles the Miocene apes Pierolapithecus, Hispanopithecus, Sivapithecus, Griphopithecus (Paşalar) ( 14,(16)(17)(18) ) and cercopithecides ( 16 and authors observations). With its more generalized hand morphology, Danuvius most likely usedpalmigrade hand postures on the ground, but with minimal hyperextension at the metacarpo-phalangeal joint, in contrast to knuckle-or fist-walking of extant great apes 14 . ...
... Locomotor differences between Miocene great apes such as dryopithecins and extant great apes are further reflected in phalangeal morphology, which in the former most closely resembles that of early Miocene stem hominoids such as proconsulids and is indicative of powerful-grasping capabilities during above-branch quadrupedalism and cautious climbing (Begun, 1993;Begun et al., 1994;Madar et al., 2002;Nakatsukasa et al., 2003;Alm ecija et al., 2007Alm ecija et al., , 2009Alm ecija et al., , 2012Alba et al., 2010a). Among dryopithecines, Hispanopithecus is an exception since its phalanges are longer and more curved than in Pierolapithecus (Alm ecija et al., 2007;Alba et al., 2010a), also from the Vall es-Pened es Basin and with a similar inferred body mass as Hispanopithecus (Moy a-Sol a et al., 2004, 2005). ...
... Taken overall, available postcranial remains more or less confidently attributed to Dryopithecus are consistent with a positional repertoire including a significant component of above-branch quadrupedalism and cautious climbing, potentially combined with antipronograde behaviors such as vertical climbing, but lacking specific adaptations to suspensory behaviors. Similar views have been advocated for the roughly coeval (12.0 Ma; Alba et al., 2017) dryopithecin P. catalaunicus from ACM/BCV1 (Moy a-Sol a et Alm ecija et al., 2009;Alba et al., 2010a;Alba, 2012), as well as for the older (ca. 16e15 Ma) Nacholapithecus kerioi (Nakatsukasa et al., 2003;Ishida et al., 2004;Nakatsukasa and Kunimatsu, 2009), further considered a putative stem hominid (Alba, 2012;Kunimatsu et al., 2019). ...
... The inference that Pierolapithecus lacked specific suspensory adaptations in spite of possessing an orthograde body plan (Moy a-Sol a et al., 2004) was mostly based on differences in phalangeal morphology and relative proportions to body mass, as compared to Hispanopithecus and extant apes. Such a contention was subsequently challenged by some authors (Begun and Ward, 2005;Deane and Begun, 2008) but supported by additional evidence by Moy a-Sol a and coworkers (Moy a-Sol a et al., 2005;Alm ecija et al., 2009;Alba et al., 2010a). Regarding suspensory adaptations, both Dryopithecus and Pierolapithecus (besides Nacholapithecus and most other middle Miocene apes) would differ from the late Miocene Hispanopithecus laietanus from Can Llobateres 2 (9.6 Ma; Casanovas-Vilar et al., 2016), which already shows clear adaptations to below-branch suspension (Moy a-Sol a and K€ ohler, 1996;Alm ecija et al., 2007;Alba et al., 2010aAlba, 2012;Pina et al., 2012) in spite of still retaining some primitive features consistent with some degree of above-branch quadrupedalism (Alm ecija et al., 2007Tallman et al., 2013). ...
Only a few postcranial remains have been assigned to the Miocene great ape Dryopithecus fontani, leading to uncertainties in the reconstruction of its overall body plan and positional behavior. Here we shed light on the locomotor repertoire of this species through the study of the femoral neck cortical bone (FNCB) distribution of IPS41724, a partial proximal femur from the Abocador de Can Mata locality ACM/C3-Az (11.9 Ma, middle Miocene; Valle�s-Penede�s Basin, Spain) attributed to this taxon. This specimen was scanned through computed tomography to measure the superior (SUP) and inferior (INF) cortical thicknesses at the middle and the base of the femoral neck. Measurements were compared with a sample of extant primates and the femur IPS18800.29 from the younger great ape Hispanopithecus laietanus from Can Llobateres 2 (9.6 Ma, late Miocene; Valle�s-Penede�s Basin), previously shown to display a homoge- neous FNCB distribution at the midneck section coupled with postcranial adaptations to below-branch suspensory behaviors. Our analyses indicate an asymmetric FNCB distribution for IPS41724 (SUP/INF index 1⁄4 ~0.4 at the midneck and base of the neck sections), comparable with that of quadrupedal pri- mates and bipedal hominins (including early australopiths), but contrasting with the homogeneous FNCB distribution of Hispanopithecus and extant great apes. An asymmetrical FNCB distribution has been associated with stereotyped loads at the hip joint (as in both quadrupedal and bipedal taxa). Our results therefore support a significant quadrupedal component of the positional behavior of Dryopithecus, thus strengthening the argument that plesiomorphic generalized quadrupedalism was still a major locomotor behavior for Miocene great apes. If that were the case, it could have deep implications for the origins of hominin bipedalism.
... The presence of suspension has been traditionally linked to a series of derived morphological traits known as orthogrady, including a broad and shallow thorax, spinal invagination, long clavicles, dorsally placed scapulae with laterally oriented glenoid fossae, highly mobile shoulder joints, ulnar deviation of the hand, lack of ulnocarpal joint, a short lumbar column with dorsally placed transverse processes, visceral fixation, and loss of an external tail (e.g., Andrews & Groves, 1976;Gebo, 1996Gebo, , 2010Keith, 1903Keith, , 1923Ward, 2015;Williams, 2012). However, with the expanding record of Miocene and Plio-Pleistocene hominoid and pliopithecoid fossils, questions have been raised as to (a) the overall homology of those traits, exclusive of hominoids, thus constituting their morphological ancestral condition (Crompton, Vereecke, & Thorpe, 2008;Gebo et al., 1997;MacLatchy, 2004;MacLatchy et al., 2000;Williams, 2012), and (b) the assumption of presence of suspensory behaviors when orthograde features are recognized (mostly in the fossil record) and vice versa (Almécija, Alba, & Moyà-Solà, 2009;Moyà-Solà et al., 2004, 2005. ...
... As discussed above, suspension has been further inferred for some extinct catarrhines retaining a pronograde body plan, most notably E. vindobonensis. On the opposite side of the spectrum is the case of Pierolapithecus, which displays a torso morphology that reflects an orthograde body plan, but lacks some key suspensory adaptations in the forelimbs, further suggesting a decoupling of the two features (Almécija et al., 2009;Moyà-Solà et al., 2004, 2005. ...
... Thus, based on current undisputed evidence available, orthogrady and suspension would have independently arisen several times throughout ape evolution. Among large-bodied apes, the acquisition of an orthograde body plan seems to have taken place first (probably originally related to vertical climbing), with a later acquisition of suspension (which would have even appeared independently in some great ape lineages; Alba, 2012;Almécija et al., 2007Almécija et al., , 2009Cartmill, 1985;Crompton et al., 2008;Fleagle, 1976;Nakatsukasa, Kunimatsu, Nakano, Takano, & Ishida, 2003;Moyà-Solà et al., 2004, 2005Sarmiento, 1998). In contrast, small-bodied primates (including extinct catarrhines such as E. vindobonensis) seem to have followed the reverse path, with suspensory adaptations being acquired on an otherwise pronograde body plan, which poses an interesting scenario for the evolution of gibbons and siamangs. ...
The glenohumeral joint, the most mobile joint in the body of hominoids, is involved in the locomotion of all extant primates apart from humans. Over the last few decades, our knowledge of how variation in its morphological characteristics relates to different locomotor behaviors within extant primates has greatly improved, including features of the proximal humerus and the glenoid cavity of the scapula, as well as the muscles that function to move the joint (the rotator cuff muscles). The glenohumeral joint is a region with a strong morphofunctional signal, and hence, its study can shed light on the locomotor behaviors of crucial ancestral nodes in the evolutionary history of hominoids (e.g., the last common ancestor between humans and chimpanzees). Hominoids, in particular, are distinct in showing round and relatively big proximal humeri with lowered tubercles and flattened and oval glenoid cavities, morphology suited to engage in a wide range of motions, which enables the use of locomotor behaviors such as suspension. The comparison with extant taxa has enabled more informed functional interpretations of morphology in extinct primates, including hominoids, from the Early Miocene through to the emergence of hominins. Here, I review our current understanding of glenohumeral joint functional morphology and its evolution throughout the Miocene and Pleistocene, as well as highlighting the areas where a deeper study of this joint is still needed. Differences in glenohumeral (shoulder) joint morphology provide key insight on the locomotor behavior of extant and extinct groups of primates, shedding light on their evolutionary history.
... In turn, inferred limb proportions [7], femoral morphology [7,23,24] and phalangeal features [7,8,25] indicate the possession of adaptations for forelimb-dominated, below-branch suspensory behaviors, including a high intermembral index and long and curved manual phalanges. At the same time, the metacarpal proportions and several morphologic details of the proximal phalanges of H. laietanus have been interpreted as indicating the retention of features functionally-related to above-branch quadrupedalism [7,8,26]. This has led to the contention that, among fossil crown hominids, palmigrady was gradually abandoned as suspensory behavior became progressively more adaptively significant [8,9,25,26]. ...
... At the same time, the metacarpal proportions and several morphologic details of the proximal phalanges of H. laietanus have been interpreted as indicating the retention of features functionally-related to above-branch quadrupedalism [7,8,26]. This has led to the contention that, among fossil crown hominids, palmigrady was gradually abandoned as suspensory behavior became progressively more adaptively significant [8,9,25,26]. Most recently, however, it has been argued that the unusual metacarpo-phalangeal morphology of H. laietanus might not reflect the retention of quadrupedal behaviors [22]. ...
... The ulna is unknown for the stem pongine Sivapithecus and the putative stem hominids Pierolapithecus and Dryopithecus, but other postcranial evidence suggests that these taxa displayed unique locomotor repertoires, currently unknown amongst extant apes, combining powerful-grasping, pronograde quadrupedalism with some orthograde behaviors but with no suspensory adaptations [25,26,36,43,62,[69][70][71][72]. Amongst Miocene apes, only the Late Miocene Oreopithecus displays a fully modern-hominoid-like elbow joint, as shown by the very short olecranon process and marked trochlear keel [43,[49][50][51]54,66,69,73]. ...
... The abundance of trees may have allowed hominoids to eat a diverse array of vegetation, ranging from leaves and soft fruits (Anoiapithecus and Dryopithecus) to harder and brittle fruits (Pierolapithecus) [11,41]. This also fits with the postcranial morphology of Pierolapithecus, which indicates an orthograde bodyplan with adaptations for arboreal vertical climbing [10,21,34,53]. Only a single Micromeryx specimen from ACM/C2-A3 (IPS29396) displays more rounded cusps and slightly higher δ 13 C and δ 18 O values. ...
... These changes toward habitat (canopy) fragmentation, leading to a mosaic of forest patches interrupted by more open woodlands and maybe even shrublands, would have represented a challenge for the frugivorous and presumably arboreal great apes from ACM-especially in dietary terms (given the impossibility of maintaining a year-round supply of ripe fruits), and perhaps also from a locomotor viewpoint (at least for the highly arboreal Pierolapithecus, given the need to travel across the canopy to exploit such resources). Admittedly, arboreal adaptations are only unambiguously recorded for the orthograde Pierolapithecus [10,21,34,53], while there are no postcranials for Anoiapithecus, and Dryopithecus appears to have been more pronograde [57]. Nevertheless, there are no indications that Dryopithecus was particularly adapted to terrestrial locomotion [57], whereas in contrast Pliopithecus has been inferred as a generalised semiarboreal quadruped [58,59], which would have allowed the latter genus to better exploit not only the shrub level but also to walk terrestrially among different arboreal feeding sources. ...
Background
The two main primate groups recorded throughout the European Miocene, hominoids and pliopithecoids, seldom co-occur. Due to both their rarity and insufficiently understood palaeoecology, it is currently unclear whether the infrequent co-occurrence of these groups is due to sampling bias or reflects different ecological preferences. Here we rely on the densely sampled primate-bearing sequence of Abocador de Can Mata (ACM) in Spain to test whether turnovers in primate assemblages are correlated with palaeoenvironmental changes. We reconstruct dietary evolution through time (ca. 12.6–11.4 Ma), and hence climate and habitat, using tooth-wear patterns and carbon and oxygen isotope compositions of enamel of the ubiquitous musk-deer Micromeryx .
Results
Our results reveal that primate species composition is strongly correlated with distinct environmental phases. Large-bodied hominoids (dryopithecines) are recorded in humid, densely-forested environments on the lowermost portion of the ACM sequence. In contrast, pliopithecoids inhabited less humid, patchy ecosystems, being replaced by dryopithecines and the small-bodied Pliobates toward the top of the series in gallery forests embedded in mosaic environments.
Conclusions
These results support the view that pliopithecoid primates preferred less humid habitats than hominoids, and reveal that differences in behavioural ecology were the main factor underpinning their rare co-occurrence during the European Miocene. Our findings further support that ACM hominoids, like Miocene apes as a whole, inhabited more seasonal environments than extant apes. Finally, this study highlights the importance of high-resolution, local investigations to complement larger-scale analyses and illustrates that continuous and densely sampled fossiliferous sequences are essential for deciphering the complex interplay between biotic and abiotic factors that shaped past diversity.
... Understanding the sequence of morphological changes in catarrhine, and especially hominoid, evolution is complicated by fossil taxa that exhibit mosaic morphologies that are not seen in any living species [11][12][13][14] . For example, palaeontological evidence suggests that some Miocene hominids (i.e. the great ape and human clade) exhibited orthograde adaptations without the accompanying specialized features related to below-branch suspensory adaptations that are seen in some living hominoids [15][16][17] . ...
... refs. 15,16,20,23,69,70 , that the catarrhine postcranium evolved in a mosaic fashion. Thus, although some extant species could better approximate ancestral morphologies than others for specific anatomical regions, 'overall ancestral body forms' are difficult to assess without thorough investigation of the fossil record. ...
The divergence of crown catarrhines—i.e., the split of cercopithecoids (Old World monkeys) from hominoids (apes and humans)—is a poorly understood phase in our shared evolutionary history with other primates. The two groups differ in the anatomy of the hip joint, a pattern that has been linked to their locomotor strategies: relatively restricted motion in cercopithecoids vs. more eclectic movements in hominoids. Here we take advantage of the first well-preserved proximal femur of the early Oligocene stem catarrhine Aegyptopithecus to investigate the evolution of this anatomical region using 3D morphometric and phylogenetically-informed evolutionary analyses. Our analyses reveal that cercopithecoids and hominoids have undergone divergent evolutionary transformations of the proximal femur from a similar ancestral morphology that is not seen in any living anthropoid, but is preserved in Aegyptopithecus, stem platyrrhines, and stem cercopithecoids. These results highlight the relevance of fossil evidence for illuminating key adaptive shifts in primate evolution. The proximal femur is key for understanding locomotion in primates. Here, the authors analyze the evolution of the proximal femur in catarrhines, including a new Aegyptopithecus fossil, and suggest that Old World monkeys and hominoids diverged from an ancestral state similar to Aegyptopithecus.
... Rather, it might represent further convergent evolution from an above-branch quadrupedal ancestor (cf. [59,60]) with short-fibred gastrocnemius muscles and a long Achilles tendon towards the long-fibred muscles facilitating the muscular control and a large range of motion that is beneficial for the arboreal lifestyles of each of the large-bodied extant non-human Hominidae (see, for instance, [5,7,16]). 9 In this context, it is remarkable that lorisines also have a short Achilles tendon comparable to great apes [4], which is interpreted as a convergent feature (next to others) related to selection for slow, cautious arboreal clambering (see, for instance, [61]). ...
... This view conforms to the suggestion by Alba et al. [60] that the last common hominoid ancestor was not necessarily great ape-like and that small-bodied catarrhines could have played a remarkable role in ape evolution. It also accords with the suggestions by Almécija et al. [59] (based on their analysis of hominoid forelimbs) that above-branch quadrupedalism inherited from stem hominoids constituted a significant component of the locomotor repertoires of different hominoid lineages at least until the Late Miocene. And finally, it also supports the suggestion by Lovejoy et al. [62,63] that the last common ancestor of the African apes probably had feet that functioned like those of living monkeys rather than like those of apes. ...
The well-developed Achilles tendon in humans is generally interpreted as an adaptation for mechanical energy storage and reuse during cyclic locomotion. All other extant great apes have a short tendon and long-fibred triceps surae, which is thought to be beneficial for locomotion in a complex arboreal habitat as this morphology enables a large range of motion. Surprisingly, highly arboreal gibbons show a more human-like triceps surae with a long Achilles tendon. Evidence for a spring-like function similar to humans is not conclusive. We revisit and integrate our anatomical and biomechanical data to calculate the energy that can be recovered from the recoiling Achilles tendon during ankle plantar flexion in bipedal gibbons. Only 7.5% of the required external positive work in a stride can come from tendon recoil, yet it is delivered at an instant when the whole-body energy level drops. Consequently, an additional similar amount of mechanical energy must simultaneously dissipate elsewhere in the system. Altogether, this challenges the concept of an energy-saving function in the gibbon's Achilles tendon. Cercopithecids, sister group of the apes, also have a human-like triceps surae. Therefore, a well-developed Achilles tendon, present in the last common 'Cercopithecoidea-Hominoidea' ancestor, seems plausible. If so, the gibbon's anatomy represents an evolutionary relict (no harm-no benefit), and the large Achilles tendon is not the premised key adaptation in humans (although the spring-like function may have further improved during evolution). Moreover, the triceps surae anatomy of extant non-human great apes must be a convergence, related to muscle control and range of motion. This perspective accords with the suggestions put forward in the literature that the last common hominoid ancestor was not necessarily great ape-like, but might have been more similar to the small-bodied catarrhines.
... Radial measurements describing humeroradial joint shape and neck morphology were from Patel (2005) and Senut (1981) (Table 1). The phalanx was compared by using the indices of midshaft robusticity of the fourth phalanges in extant nonhuman primates (Alm ecija et al., 2009) and computing the included angle ( Susman et al., 1984;Stern et al., 1995) (Table 1). For the second metatarsal, the robusticity and some architectural aspects of the plantar arches, including inclination, divergence and torsion, were quantified us- ing angles defined by Berillon (2000) while the articular set of the distal articular surface was from Duncan et al. (1994) (Table 1). ...
... OMO 323-10069 is one of the largest fourth hominin phalanges, reaching the size of the largest Hadar specimens ( Bush et al., 1982;Ward et al., 2012) (Table 1). The phalanx is robust at midshaft (Fig. 4A) and fits well with the condition seen in Gorilla, humans (Alm ecija et al., 2009), Australopithecus ( Bush et al., 1982;Kivell et al., 2011;Ward et al., 2012), and putative specimens of Para- nthropus robustus (Susman, 1989;Susman et al., 2001). In cross Figure 5. Figure S6 OMO 323-10069 is compared with other Plio-Pleistocene proximal phalanges and that of a bonobo (Pan paniscus) in side views (left) and palmar views (right). ...
... Although lower ilium height cannot be directly inferred from the Pierolapithecus ilium fragment, these noted similarities between the Pierolapithecus and Ekembo ilia hints at the possibility that the Pierolapithecus lower ilium may have only been moderately long like in Ekembo. Throughout the trunk, Pierolapithecus displays features associated with orthograde behaviors (e.g., vertebral transverse process originating on the pedicle, highly curved rib bodies, phalangeal curvature), although it lacks adaptations in the phalanges for suspensory behaviors sensu stricto (Moy a-Sol a et Alm ecija et al., 2009;Susanna et al., 2014; but see Begun and Ward, 2005). Craniodentally, Pierolapithecus aligns with all extant great apes in basic structure, although preserving a primitive hominoid sagittal profile (Moy a-Sol a et al., 2004). ...
... Only finding direct fossil evidence will reveal the bauplan of the last common ancestor of chimpanzees and hominins. However, the paleontological record continues to reveal that postcranial morphologies like those of early hominoids (e.g., Ekembo) persist fairly late into the Miocene in combination with some modern traits (Pilbeam et al., 1990;Moy a-Sol a et al., 2004;Alm ecija et al., 2009;Lovejoy et al., 2009a,b,c;Alm ecija et al., 2013;Hammond et al., 2013;Alm ecija et al., 2015;Morgan et al., 2015;White et al., 2015). If the last common ancestor of the Pan-Homo LCA did in fact have a moderate lower ilium length, the changes that the earliest hominins underwent in this region of the postcranium are less dramatic than historically assumed. ...
Elucidating the pelvic morphology of the Pan-Homo last common ancestor (LCA) is crucial for understanding ape and human evolution. The pelvis of Ardipithecus ramidus has been the basis of controversial interpretations of the LCA pelvis. In particular, it was proposed that the lower ilium became elongate independently in the orangutan and chimpanzee clades, making these taxa poor analogues for the pelvis of the LCA. This study examines the variation in relative lower ilium height between and within living and fossil hominoid species (and other anthro-poids), and models its evolution using available fossil hominoids as calibration points. We find nuanced differences in relative lower ilium height among living hominoids, particularly in regards to gorillas, which do not have elongate lower ilia (because they are likely to represent the plesio-morphic hominoid condition for this trait). We also show that differences in relative lower ilium height among hominoid taxa are not readily explained by differences in size between species. Our maximum likelihood ancestral state reconstructions support inferences that chimpanzees (Pan troglodytes in particular) and orangutans evolved their elongate lower ilia independently. We also find that the predicted lower ilium height of the Pan-Homo LCA is shorter than all great apes except gorillas. This study adds to a growing body of evidence that finds different regions of the body show different evolutionary histories in different hominoids, and underscores that the unique combinations of morphologies of each modern and fossil hominoid species should be considered when reconstructing the mosaic nature of the Pan-Homo LCA. Anat Rec, 300:828–844, 2017. V C 2017 Wiley Periodicals, Inc.
... Close relatives such as Cynocephalus and Tupaia also have dorsally canted non-pollical proximal phalanges (Boyer et al. 2013 ), which not only refl ects their more generalized quadrupedal hand posture like many primates but also the possibility that this confi guration of the McP joints may be primitive for primates. Some taxa such as Eulemur have robust palmar tubercles at the base of the proximal phalanx, another trait possibly related to palmigrady according to some authors (Rose 1986 ;Almécija et al. 2009 ). Well-developed palmar tubercles are also found in Tupaia and Cynocephalus (Boyer et al. 2013 ). ...
... Primate hand bones are small and irregular in shape. As such, quantifi cation of their morphology has primarily been limited to linear measurements, which are easy to acquire with calipers (e.g., Begun 1993 ;Almécija et al. 2009 ;Patel 2010a ) or two-dimensional measurements from photographs and radiographs (e.g., Susman 1979 ;Richmond 1998 ;Rolian 2009 ). More recently, landmarking techniques with a point digitizer have been used to capture three-dimensional angle data and for the purpose of geometric morphometric analyses; however, reliable data with acceptable accuracy and precision are only obtainable on larger hand bones like metacarpals (Rein 2011 ;Rein and McCarty 2012 ). ...
The primate hand consists of five rays: a pollex containing a metacarpal and two phalanges and four ulnar rays each containing a metacarpal and three phalanges. Morphology of these elements is related to a number of factors including behavior (such as locomotor mode and manipulatory capabilities) and phylogenetic relatedness. This chapter briefly reviews the evolutionary history of the primate hand, discusses the intrinsic proportions of bones within the rays, and emphasizes the general osteology and morphological diversity among primates and their close relatives. The functional and evolutionary consequences of anatomical specializations are reviewed. Where clear gaps in the literature exist, new preliminary descriptions and data are presented.
... A long hand is correlated with arboreal locomotion, particularly suspension (Straus 1940 ;Erikson 1963 ). However, the hand of Pierolapithecus is signifi cantly shorter than that of the similarly sized Hispanopithecus (see below), suggesting a lack of specialization for a hooklike grip (Moyà-Solà et al. 2004, 2005aAlmécija et al. 2009 also noted a relatively long pollex). The conclusion that Pierolapithecus was less specialized for suspension or orthogrady than extant great apes and late Miocene apes such as Hispanopithecus and Rudapithecus is also supported by a comparatively weak expression of SSFs in the PPs (Fig. 17.3 ). ...
... While the IA is calculated only from an intact bone, the PCF function can be calculated from fragmentary bones. Data source of IA: for extant taxa,Richmond and Jungers ( 2008 ); for fossil taxa,Richmond and Whalen ( 2001 ),Ersoy et al. ( 2008 ),Almécija et al. ( 2007Almécija et al. ( , 2009 ),Bonis and Koufos (2014). Data of Equatorius (KNM-TH 28860U) and Oreopithecus (IGF 11778 PP5) is unpublished data of S.A. Data of PCF are fromDeane and Begun ( 2008 ) Fig. 17.6 Right pollical proximal phalanges of fossil apes and Pan in palmar view. ...
Hands of extant hominoids are highly derived compared with those of non-hominoid catarrhines. The evolution of the ape hand started from an appendage very well suited for powerful pollical-assisted grasping that supplied a balancing function in response to the loss of tail as seen in the early Miocene Proconsul (or Ekembo). Nacholapithecus from the early Middle Miocene of Africa had hands that were adapted for a primitive pollical-assisted grasping function, but absolutely large and more powerful. This might be an initial change toward forelimb-dominated positional behaviors while retaining the generally plesiomorphic postcrania. Pierolapithecus from the late Middle Miocene of Europe is clearly derived and may represent an ‘intermediate’ form evolving toward the extant great ape-like suspension/orthogrady in a mosaic way: enhanced ulnar deviation and midcarpal supination, yet lacking complete radial-side loading of the wrist and specializations for a hook-like grip. Late Miocene Eurasian great apes exhibit varying degrees (or modes) of suspension and orthograde adaptations. However, the hand anatomy that invokes such behaviors is not always morphologically identical across these apes, suggesting independent specialization for those behaviors. A reduction of the pollex in relation to the fingers, a trait common in extant apes, is not observed in any of these species. This may suggest that above-branch quadrupedalism/climbing with power grasping was an indispensable locomotor behavior, even in these apes. It is unclear in the fossil record when and where extant ape-like hands evolved.
... These features imply a ventral position of the spinal column relative to the thorax, thus allowing us to infer that the latter was broad and shallow, like in extant hominoids. Overall, the vertebral morphology of H. laietanus agrees well with other postcranial elements (Moyà-Solà & Köhler, 1996;Köhler et al., 2002;Almécija et al., 2007), indicating the possession of a modern hominoid-like, orthograde bodyplan, which has been also documented in the Middle Miocene ape (11.9 Ma) Pierolapithecus catalaunicus from the same basin (Moyà-Solà et al., 2004, 2005Almécija et al., 2009;Alba et al., 2010;Susanna et al., 2010aSusanna et al., , 2010b. ...
... Although the African Early Miocene ape Morotopithecus already shows a vertebral morphology compatible with orthogrady (Sanders & Bodenbender, 1994), this taxon apparently displayed a higher number of lumbar segments than extant hominoids (Nakatsukasa, 2008). Additional remains from other anatomical regions would be required in order to confidently infer an orthograde bodyplan for Morotopithecus, so that, Pierolapithecus and Hispanopithecus first unambiguously record orthogrady, in spite of retaining adaptations to powerful-grasping palmigrady, and the former further lacking specific adaptations to suspensory behaviors (Moyà-Solà et al., 2004, 2005Almécija et al., 2007Almécija et al., , 2009 Alba et al., 2010). Pierolapithecus is generally interpreted as a stem hominid (Moyà-Solà et al., 2004, 2005 and Hispanopithecus has been proposed as a stem pongine (Moyà-Solà & Köhler, 1993, 1995Köhler et al., 2001), although other authors consider both taxa to be stem hominines (Begun, 2007(Begun, , 2009(Begun, , 2010. ...
A description and functional interpretation of the vertebral specimens of the Late Miocene (9.6 Ma) great ape Hispanopithecus laietanus (Primates: Hominidae) from Can Llobateres 2 (Vallès-Penedès Basin, NE Iberian Peninsula) are provided. These specimens consist of partial thoracic and lumbar vertebrae , corresponding to the partial skeleton IPS18800. Despite the retention of some plesiomorphic features shared with pronograde monkeys and stem hominoids, Hispanopithecus shares a set of derived features with extant great apes, which are indicative of upright trunk postures. Overall, the vertebral morphology of this taxon agrees well with other postcranial elements, indicating a modern hominoid-like, orthograde bodyplan. Orthogrady has been also documented in the Middle Miocene (11.9 Ma) putative stem hominid Pierolapithecus catalaunicus from the same basin. Although phylogenetic uncertainties still remain regarding these Miocene European dryopithecines, the lack of unambiguous or-thograde adaptations in the Asian pongine Sivapithecus raises serious doubts on the homology of these features between hylobatids and hominids, and even between pongines and hominines.
... These features imply a ventral position of the spinal column relative to the thorax, thus allowing us to infer that the latter was broad and shallow, like in extant hominoids. Overall, the vertebral morphology of H. laietanus agrees well with other postcranial elements (Solà & Köhler, 1996; Köhler et al., 2002; Almécija et al., 2007 ), indicating the possession of a modern hominoid-like, orthograde bodyplan , which has been also documented in the Middle Miocene ape (11.9 Ma) Pierolapithecus catalaunicus from the same basin (Moyà-Solà et al., 2004, 2005 Almécija et al., 2009; Alba et al., 2010; Susanna et al., 2010a Susanna et al., , 2010b). ...
... Although the African Early Miocene ape Morotopithecus already shows a vertebral morphology compatible with orthogrady (Sanders & Bodenbender, 1994 ), this taxon apparently displayed a higher number of lumbar segments than extant hominoids (Nakatsukasa, 2008). Additional remains from other anatomical regions would be required in order to confidently infer an orthograde bodyplan for Morotopithecus, so that, Pierolapithecus and Hispanopithecus first unambiguously record orthogrady, in spite of retaining adaptations to powerful-grasping palmigrady, and the former further lacking specific adaptations to suspensory behaviors (Moyà-Solà et al., 2004, 2005 Almécija et al., 2007 Almécija et al., , 2009 Alba et al., 2010). Pierolapithecus is generally interpreted as a stem hominid (Moyà-Solà et al., 2004, 2005) and Hispanopithecus has been proposed as a stem pongine (Moyà-Solà & Köhler, 1993, 1995 Köhler et al., 2001), although other authors consider both taxa to be stem hominines (Begun, 2007Begun, , 2009Begun, , 2010). ...
A description and functional interpretation of the vertebral specimens of the Late Miocene (9.6 Ma) great ape Hispanopithecus laietanus (Primates: Hominidae) from Can Llobateres 2 (Vallès-Penedès Basin, NE Iberian Peninsula) are provided. These specimens consist of partial thoracic and lumbar vertebrae , corresponding to the partial skeleton IPS18800. Despite the retention of some plesiomorphic features shared with pronograde monkeys and stem hominoids, Hispanopithecus shares a set of derived features with extant great apes, which are indicative of upright trunk postures. Overall, the vertebral morphology of this taxon agrees well with other postcranial elements, indicating a modern hominoid-like, orthograde bodyplan. Orthogrady has been also documented in the Middle Miocene (11.9 Ma) putative stem hominid Pierolapithecus catalaunicus from the same basin. Although phylogenetic uncertainties still remain regarding these Miocene European dryopithecines, the lack of unambiguous or-thograde adaptations in the Asian pongine Sivapithecus raises serious doubts on the homology of these features between hylobatids and hominids, and even between pongines and hominines.
... These features imply a ventral position of the spinal column relative to the thorax, thus allowing us to infer that the latter was broad and shallow, like in extant hominoids. Overall, the vertebral morphology of H. laietanus agrees well with other postcranial elements (Solà & Köhler, 1996; Köhler et al., 2002; Almécija et al., 2007 ), indicating the possession of a modern hominoid-like, orthograde bodyplan , which has been also documented in the Middle Miocene ape (11.9 Ma) Pierolapithecus catalaunicus from the same basin (Moyà-Solà et al., 2004, 2005 Almécija et al., 2009; Alba et al., 2010; Susanna et al., 2010a Susanna et al., , 2010b). ...
... Although the African Early Miocene ape Morotopithecus already shows a vertebral morphology compatible with orthogrady (Sanders & Bodenbender, 1994 ), this taxon apparently displayed a higher number of lumbar segments than extant hominoids (Nakatsukasa, 2008). Additional remains from other anatomical regions would be required in order to confidently infer an orthograde bodyplan for Morotopithecus, so that, Pierolapithecus and Hispanopithecus first unambiguously record orthogrady, in spite of retaining adaptations to powerful-grasping palmigrady, and the former further lacking specific adaptations to suspensory behaviors (Moyà-Solà et al., 2004, 2005 Almécija et al., 2007 Almécija et al., , 2009 Alba et al., 2010). Pierolapithecus is generally interpreted as a stem hominid (Moyà-Solà et al., 2004, 2005) and Hispanopithecus has been proposed as a stem pongine (Moyà-Solà & Köhler, 1993, 1995 Köhler et al., 2001), although other authors consider both taxa to be stem hominines (Begun, 2007Begun, , 2009Begun, , 2010). ...
A description and functional interpretation of the vertebral specimens of the Late Miocene (9.6 Ma) great ape Hispanopithecus laietanus (Primates: Hominidae) from Can Llobateres 2 (Vallès-Penedès Basin, NE Iberian Peninsula) are provided. These specimens consist of partial thoracic and lumbar vertebrae , corresponding to the partial skeleton IPS18800. Despite the retention of some plesiomorphic features shared with pronograde monkeys and stem hominoids, Hispanopithecus shares a set of derived features with extant great apes, which are indicative of upright trunk postures. Overall, the vertebral morphology of this taxon agrees well with other postcranial elements, indicating a modern hominoid-like, orthograde bodyplan. Orthogrady has been also documented in the Middle Miocene (11.9 Ma) putative stem hominid Pierolapithecus catalaunicus from the same basin. Although phylogenetic uncertainties still remain regarding these Miocene European dryopithecines, the lack of unambiguous or-thograde adaptations in the Asian pongine Sivapithecus raises serious doubts on the homology of these features between hylobatids and hominids, and even between pongines and hominines.
... These features imply a ventral position of the spinal column relative to the thorax, thus allowing us to infer that the latter was broad and shallow, like in extant hominoids. Overall, the vertebral morphology of H. laietanus agrees well with other postcranial elements (Solà & Köhler, 1996; Köhler et al., 2002; Almécija et al., 2007 ), indicating the possession of a modern hominoid-like, orthograde bodyplan , which has been also documented in the Middle Miocene ape (11.9 Ma) Pierolapithecus catalaunicus from the same basin (Moyà-Solà et al., 2004, 2005 Almécija et al., 2009; Alba et al., 2010; Susanna et al., 2010a Susanna et al., , 2010b). ...
... Although the African Early Miocene ape Morotopithecus already shows a vertebral morphology compatible with orthogrady (Sanders & Bodenbender, 1994 ), this taxon apparently displayed a higher number of lumbar segments than extant hominoids (Nakatsukasa, 2008). Additional remains from other anatomical regions would be required in order to confidently infer an orthograde bodyplan for Morotopithecus, so that, Pierolapithecus and Hispanopithecus first unambiguously record orthogrady, in spite of retaining adaptations to powerful-grasping palmigrady, and the former further lacking specific adaptations to suspensory behaviors (Moyà-Solà et al., 2004, 2005 Almécija et al., 2007 Almécija et al., , 2009 Alba et al., 2010). Pierolapithecus is generally interpreted as a stem hominid (Moyà-Solà et al., 2004, 2005) and Hispanopithecus has been proposed as a stem pongine (Moyà-Solà & Köhler, 1993, 1995 Köhler et al., 2001), although other authors consider both taxa to be stem hominines (Begun, 2007Begun, , 2009Begun, , 2010). ...
A description and functional interpretation of the vertebral specimens of the Late Miocene (9.6 Ma) great ape Hispanopithecus laietanus (Primates: Hominidae) from Can Llobateres 2 (Vallès-Penedès Basin, NE Iberian Peninsula) are provided. These specimens consist of partial thoracic and lumbar vertebrae , corresponding to the partial skeleton IPS18800. Despite the retention of some plesiomorphic features shared with pronograde monkeys and stem hominoids, Hispanopithecus shares a set of derived features with extant great apes, which are indicative of upright trunk postures. Overall, the vertebral morphology of this taxon agrees well with other postcranial elements, indicating a modern hominoid-like, orthograde bodyplan. Orthogrady has been also documented in the Middle Miocene (11.9 Ma) putative stem hominid Pierolapithecus catalaunicus from the same basin. Although phylogenetic uncertainties still remain regarding these Miocene European dryopithecines, the lack of unambiguous or-thograde adaptations in the Asian pongine Sivapithecus raises serious doubts on the homology of these features between hylobatids and hominids, and even between pongines and hominines.
... If this inferred morphology (from Figure 1 of Moyà-Solà et al., 2004) is indeed accurate, it suggests only partial adaptations in the foot Marked distal projection of the medial malleolus a Strongly keeled trochlear surface on the tibia a Articular facet on the talus is not expanded distally a Metaphyseal shape of the distal tibia that is not mediolaterally expanded a Lateral rays Broad metatarsal bases b Robust metatarsals with thick plantar tubercles b Proximal articular facet angled medially relative to the diaphyseal long axis b a Tallman et al. (2013), b Begun (1994) of this taxon for vertical climbing and scrambling. This interpretation is consistent with analyses from the rest of the skeleton, which suggest only modest adaptations for orthogrady (Moyà-Solà et al., 2004;Hammond et al., 2013), and the retention of quadrupedal locomotion (Almécija et al., 2009; but see Deane & Begun, 2008 for an alternative locomotor interpretation based on the hand phalanges). ...
Feet are relatively well represented in the Miocene hominoid fossil record, and taxa present a variety of adaptations. The oldest, African taxa generally present feet with evidence of strong hallucial grasps and some modest eversion-inversion capabilities, but that were narrow like cercopithecoids and probably still fairly rigid, functioning as a lever for propulsion during quadrupedal locomotion. For many taxa, there is evidence that the forelimb is adapted to orthograde locomotion while the foot presents traits that imply rather standardized quadrupedal movements, suggesting that they had a type of locomotion that has no modern equivalent. Evidence of an anterior foot that is more mobile and splayed occurs with the later Asian and European taxa. It is only with the 6–7 million year-old European Oreopithecus that pedal morphology indicates a locomotor mode closely resembling that of extant large apes with mobile, strongly grasping feet, a specialization for arboreal scrambling and careful climbing and a more generalized orthograde posture. More research is needed, however, to establish the extent of independent acquisition of these traits in extant great apes.
... Thanks to continued paleontological surveillance of the digging activity during the construction of a dump between 2002 and 2014, a diverse primate assemblage (Alba, 2012;Marig o et al., 2014;Alba et al., 2017;DeMiguel et al., 2021;Fortuny et al., 2021) has been recovered from the Middle to Late Miocene stratigraphic sequence of Abocador de Can Mata (ACM; Alba et al., 2006Alba et al., , 2011aAlba et al., , 2017 in the fossiliferous area of els Hostalets de Pierola (Catalonia, Spain). Both small-bodied catarrhines (Alba et al., 2010;2012a, 2015 and large-bodied apesdPierolapithecus (Moy a-Sol a et Alm ecija et al., 2009; P erez de los Ríos et al., 2012;Hammond et al., 2013;Pina et al., 2014), Dryopithecus (Moy a-Sol a et al., 2009a; Alba and Moy a-Sol a, 2012; Pina et al., 2019Pina et al., , 2020, and Anoiapithecus (Moy a-Sol a et al., 2009b; Alba et al., 2013)dhave been recovered there, spanning from~12.4e12.3 to~11.6 ...
The Abocador de Can Mata (ACM) composite stratigraphic sequence (els Hostalets de Pierola, Vallès-Penedès Basin, NE Iberian Peninsula) has yielded a diverse primate assemblage from the late Aragonian (Middle to Late Miocene). Detailed litho-, bio-, and magnetostratigraphic control has enabled an accurate dating of these fossil remains. Comparable data, however, were lacking for the nearby locality of Can Mata 1 (CM1), which yielded a dryopithecine canine of a female individual. Given the lack of hipparionin equids and giraffids, CM1 has been correlated to the latest Aragonian (Mammal Neogene [MN] zone MN7+8). Here we revise the age of CM1 based on fieldwork and associated paleomagnetic samplings undertaken in 2018–2021. Our results extend the ACM composite sequence upward and indicate that CM1 correlates to the earliest Vallesian (MN9). The updated ACM sequence has a thickness of ∼300 m and comprises 12 magnetozones correlated to subchrons C5Ar.1r to C5n.2n (∼12.6–11.1 Ma; latest MN6 to earliest MN9, late Aragonian to earliest Vallesian). CM1 is correlated to C5r.1r (11.146–11.056 Ma), with an interpolated age of 11.11 Ma, thus postdating the dispersal of hipparionin horses into the Vallès-Penedès Basin—which is correlated to the previous subchron C5r.1n, with an interpolated age of 11.18 Ma, and by definition marks the beginning of the Vallesian. CM1 also minimally postdates the earliest record of giraffids at ACM—representing their earliest well-dated occurrence in the basin—being correlated to C5r.1n with an interpolated age of 11.11 Ma. We conclude that CM1 has an earliest Vallesian (MN9) age of ∼11.1 Ma, intermediate between the Aragonian dryopithecins and the Vallesian hispanopithecins. Ongoing paleontological surveillance at ACM thus offers the prospect to yield additional earliest Vallesian ape remains, which are essential to clarify their taxonomic allocation as well as to confirm whether hispanopithecins evolved locally from dryopithecins rather than immigrating from elsewhere during MN9.
... Stem and crown hominids from the Middle-Late Miocene display many features and/or combinations of features not found in living apes, and this morphological disparity complicates phylogenetic inference. For instance, while all extant apes use variations of vertical climbing and below-branch suspensory postures and locomotion combined with other behaviors such as knucklewalking, clambering, or leaping (Fleagle, 1976;Hunt, 1991;Hunt et al., 1996;Thorpe and Crompton, 2006), some fossil apes from the Middle-Late Miocene preserve morphology that has been interpreted as evidence for arboreal or terrestrial quadrupedalism and many lack specialized adaptations for suspensory behaviors (e.g., Napier and Davis, 1959;Rose, 1984Rose, , 1986Pilbeam et al., 1990;Ward, 1993;McCrossin, 1994;Benefit and McCrossin, 1995;McCrossin et al., 1998;Madar et al., 2002;Sherwood et al., 2002;Ishida et al., 2004;Moy a-Sol a et al., 2004;Alm ecija et al., 2009;Patel et al., 2009;Morgan et al., 2015). Some fossil taxa also differ from extant hominids in their patterns of sexual dimorphism, showing an extremely high degree of postcanine dental size and inferred body size dimorphism that is greater than in living primates (Kelley and Xu, 1991;Kelley and Plavcan, 1998;Schrein, 2006;Scott et al., 2009). ...
Despite intensive study, many aspects of the evolutionary history of great apes and humans (Hominidae) are not well understood. In particular, the phylogenetic relationships of many fossil taxa remain poorly resolved. This study aims to provide an updated hypothesis of phylogenetic relationships for Middle-Late Miocene fossil apes, focusing on those taxa typically considered to be great apes. The character matrix compiled here samples 274 characters from the skull, dentition, and postcranium. Multiple iterations were performed to examine the effects of ingroup taxon selection, outgroup constraints, treatment of continuous data, character partitions (craniodental, postcranial), and missing data. Parsimony and Bayesian methods were used to infer phylogenetic relationships. Most European hominoids (Hispanopithecus, Rudapithecus, Dryopithecus, Pierolapithecus) are recovered as stem hominids, not more closely related to orangutans or to African apes and humans (Homininae), whereas Ouranopithecus, Graecopithecus, and Nakalipithecus are inferred to be members of the hominine clade. Asian fossil hominoids, with the exception of Lufengpithecus hudienensis, are recovered as part of the orangutan clade (Ponginae). Results suggest that Kenyapithecus and Griphopithecus are possible stem hominids, whereas Equatorius and Nacholapithecus are consistently recovered as stem hominoids. Oreopithecus and Samburupithecus are not recovered as hominids. Results of Bayesian analyses differ from those of parsimony analyses. Craniodental and postcranial character partitions are incongruent in the placement of hylobatids, which is interpreted as evidence that hylobatids and hominids independently evolved adaptations to suspensory positional behaviors. An understanding of phylogenetic relationships is necessary to address many of the questions asked in paleoanthropology. Thus, the updated hypothesis of phylogenetic relationships presented here can be used to gain a better understanding of important morphological transitions that took place during hominid evolution, ancestral morphotypes at key nodes, and the biogeography of the clade.
... The huge sampling effort at the middle to late Miocene stratigraphic section of Abocador de Can Mata (ACM), at els Hostalets de Pierola (Alba et al., 2006(Alba et al., , 2017, has uncovered a previously unsuspected diversity of primates from 12.4 to 11.6 Ma (Alba et al., 2017). They include small-bodied catarrhines (Alba et al., 2010a(Alba et al., , 2012a(Alba et al., , 2015; Alba and Moy a-Sol a, 2014; Urciuoli et al., 2018) and three species of dryopithecine great apes (Moy a- Sol a et al., , 2009aAlm ecija et al., 2009;Casanovas-Vilar et al., 2011;Alba, 2012; Alba and Moy a-Sol a, 2012; P erez de los Ríos et al., 2012;Alba et al., 2013Alba et al., , 2017Hammond et al., 2013;Marig o et al., 2014;Pina et al., 2014): Pierolapithecus catalaunicus Moy a-Sol a et al., 2004 at 12.0 Ma; Anoiapithecus brevirostris Moy a-Sol a et al., 2009b at 12.4e12.0 Ma; and D. fontani at 11.9 Ma. ...
... The Miocene hominoid fossil record demonstrates that these features have not evolved en bloc. For example, Nacholapithecus has long forelimbs and phalanges, but a narrow, monkey-like thorax and lumbar region (Nakatsukasa et al., 1998(Nakatsukasa et al., , 2003(Nakatsukasa et al., , 2007Ishida et al., 2004), whereas Pierolapithecus has a broad thorax like modern great apes, but relatively short and straight manual phalanges (Moy a-Sol a et al., 2004;Alm ecija et al., 2009). ...
Odd-nosed monkeys ‘arm-swing’ more frequently than other colobines. They are therefore somewhat behaviorally analogous to atelines and apes. Scapular morphology regularly reflects locomotor mode, with both arm-swinging and climbing anthropoids showing similar characteristics, especially a mediolaterally narrow blade and cranially angled spine and glenoid. However, these traits are not expressed uniformly among anthropoids. Therefore, behavioral convergences in the odd-nosed taxa of Nasalis, Pygathrix, and Rhinopithecus with hominoids may not have resulted in similar structural convergences. We therefore used a broad sample of anthropoids to test how closely odd-nosed monkey scapulae resemble those of other arm-swinging primates. We used principal component analyses on size-corrected linear metrics and angles that reflect scapular size and shape in a broad sample of anthropoids. As in previous studies, our first component separated terrestrial and above-branch quadrupeds from clambering and arm-swinging taxa. On this axis, odd-nosed monkeys were closer than other colobines to modern apes and Ateles. All three odd-nosed genera retain glenoid orientations that are more typical of other colobines, but Pygathrix and Rhinopithecus are closer to hominoids than to other Asian colobines in mediolateral blade breadth, spine angle, and glenoid position. This suggests that scapular morphology of Pygathrix may reflect a significant reliance on arm-swinging and that the morphology of Rhinopithecus may reflect more reliance on general climbing. As ‘arm-swinging’ features are also found in taxa that only rarely arm-swing, we hypothesize that these features are also adaptive for scrambling and bridging in larger bodied anthropoids that use the fine-branch component of their arboreal niches.
... The single lumbar vertebra known is similar to great ape vertebrae in its robustness and reduced wedging angle, both of which indicate this fossil ape had a relatively rigid lower back. The wrist is similar to that of the great apes, but the phalanges are short and less curved than in other fossil apes [Begun, 1993], This monkey-like hand is associated with apparent great ape characters linked supposedly with suspensory behaviour [Almécija et al., 2007[Almécija et al., , 2009. ...
For much of their history, fossil apes retained many monkey-like features in posture and body structure. They also occupied a range of habitats, of which tropical forest was only a part, and there is evidence of increasing terrestriality in the fossil record as it is known at present (2019). In the early Miocene (18–20 million years ago, Ma), fossil apes were pronograde arboreal slow climbers, associated mainly with forest environments and deciduous woodland and with some indications of terrestrial behaviour, particularly the larger species. Their hands had long and opposable thumbs, and the phalanges were curved. In the early middle Miocene (15–16 Ma), apes were still monkey-like in body plan and posture and were associated almost entirely with non-forest, deciduous woodland habitats, with increasing evidence of terrestrial adaptations. Hand proportions remained the same. Towards the end of the middle Miocene (12 Ma), some fossil ape species had broadened chests, long clavicles, medial torsion of the humerus and re-positioning of the scapula to the back. These adaptations may have been linked with more upright posture, as in the living apes, but unlike them, the hand phalanges were short, robust and less curved, and the thumb remained long. Associated environments were deciduous woodland rather than forest. This body plan was retained in part in some later Miocene apes (10 Ma), some of which also had more elongated limbs and hands (thumb length not known), and hind limbs modified for greater flexibility, analogous with the orang utan. Associated environments were subtropical deciduous woodlands and subtropical evergreen laurophyllous woodland in southern Europe. Other late Miocene European apes had adaptations for living on the ground, and some of these also shared characters of the skull with orang utans. They are associated with more open deciduous woodland habitats. This body plan and environment were retained in the early hominin, Ardipithecus ramidus , but with a more robust postcranial skeleton and incipient bipedalism. Based on shared character states in fossil apes, living apes and early hominins, 27 characters are identified as probable attributes of the last common ancestor (LCA) of apes and humans. The likely environment of the LCA was tropical deciduous woodland with some evidence of more open habitats, and this remained unchanged in the transition from apes to early hominins.
... As táticas evolutivas foram adquiridas, ao longo de milhões de anos, em resposta às adaptações necessárias às alterações do meio, seguidas por mudanças na fisiologia e na bioquímica da alimentação (ALMÉCIJA et al., 2009;POLLICK et al., 2007;YOUNG, 2003). Os genes que melhor se adaptam às mudanças do meio e que provocam alterações na população são selecionados naturalmente e dessa maneira ocorre o processo de evolução. ...
Os alimentos possuem grande importância para o desenvolvimento dos organismos e a expressividade gênica está inteiramente ligada aos fatores nutricionais. Dependendo dos alimentos, os animais podem desenvolver características, comportamentos e funções metabólicas não peculiares a espécie, ocasionando um processo de especiação ao longo das sucessivas gerações. Os primatas da atualidade têm se destacado devido a mudança no padrão de alimentação uma vez que as espécies que habitam ambientes urbanos desenvolveram novas habilidades e padrões comportamentais diferenciados das populações naturais.
... Therefore, our new finding provides additional evidence to support the view that a number of postcranial characters have evolved in parallel between the hylobatids and great apes (Larson, 1998;Ward, 2007;Alm ecija et al., 2015). Pierolapithecus from 12 Ma-old Spain is widely accepted as a stem great ape exhibiting an orthograde body plan but lacking specialized hands for belowbranch suspension (Moy a-Sol a et Alm ecija et al., 2009). If Nacholapithecus is a great ape, it would indicate that not only suspensory adaptations but also the orthograde body plan have evolved independently in hylobatids and hominids. ...
... So, whereas Begun interprets the presence of extant ape-like morphologies of the thorax, lower back, and limbs of Miocene apes such as Morotopithecus, Pierolapithecus (which he calls Dryopithecus), Hispanopithecus, and Rudapithecus as functional indicators of suspensory behavior (and, with the exception of Morotopithecus, as shared derived features with extant apes), Andrews (2016:248) sees orthogrady as potentially "pre-adaptive" for suspension, but not indicative of it. The latter hypothesis, which proposes that orthogrady and suspensory behavior were decoupled in hominoid evolution, was proposed in the original description and interpretation of the hand morphology of Pierolapithecus (Moy a-Sol a et al., 2004Alm ecija et al., 2009; but see; Begun and Ward, 2005), and has stimulated the application of new analytical Begun, 2008, 2010;Alba et al., 2010) and comparative morphological (e.g., Russo and Williams, 2015) approaches to test it. ...
... Ward, 1997;Pilbeam and Young, 2001;Richmond and Whalen, 2001;Madar et al., 2002;Nakatsukasa, 2003;Machnicki et al., 2016). Pierolapithecus, on the other hand, likely engaged in some below-branch arboreality, though perhaps was less specialized for these activities than extant apes (Alm ecija et al., 2009). The small fragment of ilium known for Pierolapithecus has Ekembo-like iliac tuberosity width but a wider iliac blade more like extant apes, and provides the first evidence that geometric changes in the pelvis are beginning to occur in the very latest middle Miocene (11.9 Ma; Hammond et al., 2013). ...
Orientation of the iliac blades is a key feature that appears to distinguish extant apes from monkeys. Iliac morphology is hypothesized to reflect variation in thoracic shape that, in turn, reflects adaptations for shoulder and forearm function in anthropoids. Iliac orientation is traditionally measured relative to the acetabulum, whereas functional explanations pertain to its orientation relative to the cardinal anatomical planes. We investigated iliac orientation relative to a median plane using digital models of hipbones registered to landmark data from articulated pelves. We fit planes to the iliac surfaces, midline, and acetabulum, and investigated linear metrics that characterize geometric relationships of the iliac margins. Our results demonstrate that extant hominoid ilia are not rotated into a coronal plane from a more sag-ittal position in basal apes and monkeys but that the apparent rotation is the result of geometric changes within the ilia. The whole ilium and its gluteal surface are more coronally oriented in apes, but apes and monkeys do not differ in orientation of the iliac fossa. The angular differences in the whole blade and gluteal surface primarily reflect a narrower iliac tuberosity set closer to the midline in extant apes, reflecting a decrease in erector spinae muscle mass associated with stiffening of the lumbar spine. Mediolateral breadth across the ventral dorsal iliac spines is only slightly greater in extant apes than in monkeys. These results demonstrate that spinal musculature and mobility have a more significant effect on pelvic morphology than does shoulder orientation, as had been previously hypothesized. Breadth and orientation of the iliac blades are key features that distinguish extant apes from monkeys (Straus
... Most subsequent hypotheses dealing with human hand evolution have been framed assuming a "long-fingered/short-thumbed" chimpanzee-like hand as the starting point, with strong selective pressures acting to reverse these proportions in the context of stone toolmaking and/or as a by-product of drastic changes in foot morphology (Rolian et al., 2010). However, the current fossil evidence of early hominins (Alba et al., 2003;Lovejoy et al., 2009;Almécija et al., 2010;Kivell et al., 2011) and fossil apes (Napier and Davis, 1959;Moyà-Solà et al., 2004;Almécija et al., 2007Almécija et al., , 2009) challenges this paradigm. Collectively these fossils indicate that hand proportions fairly similar to the modern human condition might in fact be plesiomorphic for the hominoid clade (Alba et al., 2003;Almécija et al., 2010;Almécija and Alba, 2014), as was previously suggested before molecular phylogenetics. ...
Humans possess the most advanced manipulative skills among hominoid primates and produce the most sophisticated technology. This capability is reflected in (1) human hand anatomy, facilitating opposition during precision grasping; and (2) neurobiological structure and function, conferring humans with enhanced neocortical control over behavior. This stark human–ape dichotomy is less clear when looking at the fossil record, in part due to the difficulty of assessing primitive versus derived (ie, " uniquely human ") features. We review the evolutionary history of the link between the hand and brain in primates, with a view toward understanding the emergence of human tool culture. 3.16.1 Background As compared to our closest living relatives (chimpanzees and bonobos), humans are distinctive in exhibiting a combination of " unique " features including a peculiar form of locomotion (bipedalism), a large brain, and highly dexterous hands (Fig. 1). Ever since Darwin (1871), these three traits have been argued to be integrally related, although it is unclear precisely in what manner. For example, Darwin (1871) believed that the necessity to use stone tools for food acquisition played an important role in a reciprocal feedback loop with cognition/brain size promoting the appearance of habitual terrestrial bipedalism to free the hands from locomotor demands. Lovejoy (1981) similarly highlighted the coevolution of bipedalism and dependence on unen-cumbered hands for carrying food over long distances in a model of human origins where a monogamous male-provisioning system promoted the emergence of habitual bipedalism. Other models imply that stone tools were a major force leading to drastic changes in gross hand anatomy (eg, Susman, 1988, 1994; Skinner et al., 2015). However, other fossil evidence and analyses show that modern humanlike hand proportions evolved prior the advent of systematic flaked stone tool culture in human evolution (Alba et al., 2003; Almécija et al., 2010, 2015b). Although the order of the causal factors is not yet entirely understood, there is a general agreement that the evolution of manipulative capabilities and bipedalism in humans were interrelated. Hands released from a function in locomotion may have provided an opportunity for the evolution of increased manipulative dexterity, but this release from locomotor function would not be sufficient on its own. Further changes in the neural control of the movements of the hand would also be necessary. For example, Napier (1962) described the hand bones at the 1.75-million-year-old FLK NN1 site in the Olduvai Gorge of Tanzania, which were later included in the holotype of /Homo habilis/ (Leakey et al., 1964). However, Napier remarked that although that hand appeared suited to produce the simple stone tools found at the site (as Napier himself replicated using only /power grip/, see below), the " intellectual " factor must also be taken into account when making such paleobiological inferences. In fact, the definition of the genus Homo was subsequently emended to include precision grip and an endocranial volume (ECV) approaching the " cerebral Rubicon " for Homo of 750 cc (Leakey et al., 1964). More recent findings, however, challenge the notion that enhanced manual dexterity, an enlarged brain, and stone tool production were temporally synchronized at the dawn of the genus Homo. Notably, new fossil evidence indicates that earlier hominins, Evolution of Nervous Systems, 2nd edition, Volume 3 http://dx.
... This model, however, is not intended to be all encompassing for ape and human forelimb evolution and development. The relatively short meta carpals relative to total phalangeal length observed in Ardipithecus (Lovejoy et al. 2009a) and many Miocene hominoids (Almecija et al. 2009) suggest parallel changes in digit propor tions in African apes and humans influenced by other developmental mechanisms (Hamrick 2001;Reno 2014). In addition, while this is a plausible scenario that accords with the available morphological and developmental data, it is difficult to prove that such a mechanism underlies the evolution of hominoid limb proportions in the absence of gene expression data during ape and human limb development and/or the identification of functional genomic changes that regulate skeletal growth. ...
Comparative embryology played an important role in anthropological investigations of the first half of the 20th century (Schultz 1925, 1926), but the frequency of these studies waned due to methodological challenges and ethical considerations of working on long‐lived, slow reproducing, and often endangered primates. Due to
these limitations it has been difficult to link genetic, developmental, and morphological evolution in primates. Evolutionary developmental biology (evo‐devo) has emerged from relatively recent inclusion of developmental genetics and embryology into the Modern Synthesis (Gilbert et al. 1996; Raff 2000). This has resulted from
technological advances in molecular genetics that enable the roles of individual genes to be tracked and tested during embryological development and led to paradigmatic shifts in the understanding of the depth to which many developmental genes and processes are highly conserved (Carroll 2008). Evolutionary developmental
anthropology can take advantage of a broad range of phenotypic, genetic, and embryological analyses to identify the genomic and developmental mechanisms underlying the intraspecific variation and evolutionary diversity of human and primate anatomy (Lovejoy et al. 1999, 2003; Carroll 2003).
Hominoids diverged from cercopithecoids during the Oligocene in Afro-Arabia, initially radiating in that continent and subsequently dispersing into Eurasia. From the Late Miocene onward, the geographic range of hominoids progressively shrank, except for hominins, which dispersed out of Africa during the Pleistocene. Although the overall picture of hominoid evolution is clear based on available fossil evidence , many uncertainties persist regarding the phylogeny and paleobiogeography of Miocene apes (nonhominin hominoids), owing to their sparse record, pervasive homoplasy, and the decimated current diversity of this group. We review Miocene ape systematics and evolution by focusing on the most parsimonious cladograms published during the last decade. First, we provide a historical account of the progress made in Miocene ape phylogeny and paleobiogeography, report an updated classification of Miocene apes, and provide a list of Miocene ape species-locality occurrences together with an analysis of their paleobiodiversity dynamics. Second, we discuss various critical issues of Miocene ape phylogeny and paleobiogeography (hylobatid and crown hominid origins, plus the relationships of Oreopithecus) in the light of the highly divergent results obtained from cladistic analyses of craniodental and postcranial characters separately. We conclude that cladistic efforts to disentangle Miocene ape phylogeny are potentially biased by a long-branch attraction problem caused by the numerous postcranial similarities shared between hylobatids and hominidsddespite the increasingly held view that they are likely ho-moplastic to a large extent, as illustrated by Sivapithecus and Pierolapithecusdand further aggravated by abundant missing data owing to incomplete preservation. Finally, we argue thatdbesides the recovery of additional fossils, the retrieval of paleoproteomic data, and a better integration between cladistics and geometric morphometricsdMiocene ape phylogenetics should take advantage of total-evidence (tip-dating) Bayesian methods of phylogenetic inference combining morphologic, molecular, and chro-nostratigraphic data. This would hopefully help ascertain whether hylobatid divergence was more basal than currently supported.
The hominins diverged from other hominoids during the Miocene. This epoch holds clues to the time, place, and circumstances of our origin, but the search for that information offered surprises. Ape species proved to be far abundant than expected and discerning the first hominins amid the variety of forms is more challenging than expected. Traits thought to be uniquely human, including bipedalism, turned out to have evolved in parallel many times. The molecular clock allows us to use genetic comparisons to establish splitting times independently of the fossil record. Three genera, thought to be early hominins are described from the Late Miocene of Africa. This is still too meager a sample to answer our larger questions.
Extensive fieldwork at Abocador de Can Mata (north-east Iberian Peninsula) has uncovered a previously unsuspected diversity of catarrhine primates in the middle Miocene (12.5–11.6 Ma) of Europe. However, the distinction of the great ape genera Pierolapithecus and Anoiapithecus from Dryopithecus (supported by craniodental differences) has been disputed by some authors. Here we revisit the diversity of great apes (dryopithecines) from the Iberian Miocene based on molar 3D endostructural morphology (relative enamel thickness, enamel distribution, and enamel–dentine junction (EDJ)). Using microtomography, we inspected an extensive sample of 49 hominoid molars representing at least five species from 12 localities. 2D and 3D relative enamel thickness values indicate that Dryopithecus and ‘Sivapithecus’ occidentalis (species inquirenda) display the thinnest and thickest enamel, respectively, while the remaining taxa (Hispanopithecus, Anoiapithecus, Pierolapithecus) show intermediate values. Upper molar enamel distribution maps exhibit a similar pattern in P. catalaunicus, A. brevirostris, D. fontani, H. laietanus and H. crusafonti whereas for the lower molars they reveal differences between H. laietanus and H. crusafonti. Lower molar enamel distribution and EDJ morphology of ‘S.’ occidentalis support the distinction of this species but do not resolve whether it is a junior synonym of Anoiapithecus brevirostris or Pierolapithecus catalaunicus. Overall our results support the distinction of middle Miocene dryopithecins from late Miocene hispanopithecins, the distinction of Pierolapithecus and Anoiapithecus from Dryopithecus among the former, and the distinct species status of H. crusafonti compared to H. laietanus among the latter. Our results highlight the potential of inner tooth morphology for hominoid alpha-taxonomy.
Although extensive research has been carried out in recent years on the origin and evolution of human bipedalism, a full understanding of this question is far from settled. Miocene hominoids are key to a better understanding of the locomotor types observed in living apes and humans. Pierolapithecus catalaunicus, an extinct stem great ape from the middle Miocene (c. 12.0 Ma) of the Vallès‐Penedès Basin (north‐eastern Iberian Peninsula), is the first undoubted hominoid with an orthograde (erect) body plan. Its locomotor repertoire included above‐branch quadrupedalism and other antipronograde behaviours. Elucidating the adaptive features present in the Pierolapithecus skeleton and its associated biomechanics helps us to better understand the origin of hominoid orthogrady. This work represents a new biomechanical perspective on Pierolapithecus locomotion, by studying its patella and comparing it with those drawn from a large sample of extant anthropoids. This is the first time that the biomechanical patellar performance in living non‐human anthropoids and a stem hominid has been studied using finite element analysis (FEA). Differences in stress distribution are found depending on body plan and the presence/absence of a distal apex, probably due to dissimilar biomechanical performances. Pierolapithecus’ biomechanical response mainly resembles that of great apes, suggesting a similar knee joint use in mechanical terms. These results underpin previous studies on Pierolapithecus, favouring the idea that a relevant degree of some antipronograde behaviour may have made up part of its locomotor repertoire. Moreover, our results corroborate the presence of modern great ape‐like knee biomechanical performances back in the Miocene.
The Evolutionary Biology of the Human Pelvis - by Cara M. Wall-Scheffler January 2020
Cambridge Core - Biological Anthropology and Primatology - The Evolutionary Biology of the Human Pelvis - by Cara M. Wall-Scheffler
Many ideas have been proposed to explain the origin of bipedalism in hominins and suspension in great apes (hominids); however, fossil evidence has been lacking. It has been suggested that bipedalism in hominins evolved from an ancestor that was a palmigrade quadruped (which would have moved similarly to living monkeys), or from a more suspensory quadruped (most similar to extant chimpanzees)1. Here we describe the fossil ape Danuvius guggenmosi (from the Allgäu region of Bavaria) for which complete limb bones are preserved, which provides evidence of a newly identified form of positional behaviour—extended limb clambering. The 11.62-million-year-old Danuvius is a great ape that is dentally most similar to Dryopithecus and other European late Miocene apes. With a broad thorax, long lumbar spine and extended hips and knees, as in bipeds, and elongated and fully extended forelimbs, as in all apes (hominoids), Danuvius combines the adaptations of bipeds and suspensory apes, and provides a model for the common ancestor of great apes and humans. Danuvius guggenmosi moved using extended limb clambering, thus combining adaptations of bipeds and suspensory apes and providing evidence of the evolution of bipedalism and suspension climbing in the common ancestor of great apes and humans.
Substantial differences among the pelves of anthropoids have been central to interpretations of the selection pressures that shaped extant hominoids, yet the evolution of the hominoid pelvis has been poorly understood due to the scarcity of fossil material. A recently discovered partial hipbone attributed to the 10 million-year-old fossil ape Rudapithecus hungaricus from Rudabánya, Hungary, differs from the hipbones of cercopithecids and earlier apes in functionally significant ways. Comparisons were made to extant and other fossil anthropoids using combination of non-landmark-based and linear metrics. Measurements were taken on 3D polygonal models of hipbones collected using laser scans. These metrics capture functionally relevant morphology given the incomplete preservation of the Rudapithecus specimen. This fossil displays features that reflect changes in spinal musculature and torso structure found only in extant great and lesser apes among hominoids. Rudapithecus has an expanded cranial acetabular lunate surface related to orthograde positional behaviors, a shallow acetabulum and relatively short ischium like orangutans and hylobatids. It displays evidence of moderately coronally-oriented iliac blades as in all extant apes and Ateles, and flaring iliac blade shape of siamangs and great apes, associated with some level of spinal stiffness. However, this fossil lacks the long lower ilium that characterizes chimpanzees, gorillas and orangutans, associated with their reduction of the number of lumbar vertebrae. The R. hungaricus pelvis demonstrates that the extreme elongation of the lower ilium seen in extant great apes does not necessarily accompany adaptation to orthograde posture and forelimb-dominated arboreal locomotion in hominoid evolution. Lower iliac elongation appears to have occurred independently in each lineage of extant great apes, supporting the hypothesis that the last common ancestor of Pan and Homo may have been unlike extant great apes in pelvic length and lower back morphology.
Considerable taxonomic diversity has been recognised among early Miocene catarrhines (apes, Old World monkeys, and their extinct relatives). However, locomotor diversity within this group has eluded characterization, bolstering a narrative that nearly all early catarrhines shared a primitive locomotor repertoire resembling that of the well-described arboreal quadruped Ekembo heseloni. Here we describe and analyse seven catarrhine capitates from the Tinderet Miocene sequence of Kenya, dated to ~20 Ma. 3D morphometrics derived from these specimens and a sample of extant and fossil capitates are subjected to a series of multivariate comparisons, with results suggesting a variety of locomotor repertoires were present in this early Miocene setting. One of the fossil specimens is uniquely derived among early and middle Miocene capitates, representing the earliest known instance of great ape-like wrist morphology and supporting the presence of a behaviourally advanced ape at Songhor. We suggest Rangwapithecus as this catarrhine’s identity, and posit expression of derived, ape-like features as a criterion for distinguishing this taxon from Proconsul africanus. We also introduce a procedure for quantitative estimation of locomotor diversity and find the Tinderet sample to equal or exceed large extant catarrhine groups in this metric, demonstrating greater functional diversity among early catarrhines than previously recognised.
Considerable taxonomic diversity has been recognised among early Miocene catarrhines (apes, Old World monkeys, and their extinct relatives). However, locomotor diversity within this group has eluded characterization, bolstering a narrative that nearly all early catarrhines shared a primitive locomotor repertoire resembling that of the well-described arboreal quadruped Ekembo heseloni. Here we describe and analyse seven catarrhine capitates from the Tinderet Miocene sequence of Kenya, dated to ~20 Ma. 3D morphometrics derived from these specimens and a sample of extant and fossil capitates are subjected to a series of multivariate comparisons, with results suggesting a variety of locomotor repertoires were present in this early Miocene setting. One of the fossil specimens is uniquely derived among early and middle Miocene capitates, representing the earliest known instance of great ape-like wrist morphology and supporting the presence of a behaviourally advanced ape at Songhor. We suggest Rangwapithecus as this catarrhine’s identity, and posit expression of derived, ape-like features as a criterion for distinguishing this taxon from Proconsul africanus. We also introduce a procedure for quantitative estimation of locomotor diversity and find the Tinderet sample to equal or exceed large extant catarrhine groups in this metric, demonstrating greater functional diversity among early catarrhines than previously recognised.
We describe eleven hominin metacarpals and phalanges recovered from Jacovec Cavern and Member 4 of the Sterkfontein Formation between 1998 and 2003. Collectively, the fossils date in excess of 2.0 Ma, and are probably attributable to Australopithecus africanus and/or Australopithecus prometheus. When combined with results of previous studies on Australopithecus postcranial functional morphology, the new data presented here suggest that at least some late Pliocene and/or early Pleistocene hominins from Sterkfontein were arboreally adept. This finding accords with the reconstruction of the site's >2.0 Ma catchment area as well-vegetated and containing significant woody components. In addition, most of the new specimens described here evince morphologies that indicate the hands from which they derived lacked complete modern humanlike manual dexterity, which is integral to the manufacture and use of intentionally shaped stone tools. The absence of lithic artifacts from both stratigraphic units from which the fossils were excavated is consistent with this conclusion.
Objectives:
Gorillas, along with chimpanzees and bonobos, are ubiquitously described as 'knuckle-walkers.' Consequently, knuckle-walking (KW) has been featured pre-eminently in hypotheses of the pre-bipedal locomotor behavior of hominins and in the evolution of locomotor behavior in apes. However, anecdotal and behavioral accounts suggest that mountain gorillas may utilize a more complex repertoire of hand postures, which could alter current interpretations of African ape locomotion and its role in the emergence of human bipedalism. Here we documented hand postures during terrestrial locomotion in wild mountain gorillas to investigate the frequency with which KW and other hand postures are utilized in the wild.
Materials and methods:
Multiple high-speed cameras were used to record bouts of terrestrial locomotion of 77 habituated mountain gorillas at Bwindi Impenetrable National Park (Uganda) and Volcanoes National Park (Rwanda).
Results:
We captured high-speed video of hand contacts in 8% of the world's population of mountain gorillas. Our results reveal that nearly 40% of these gorillas used "non-KW" hand postures, and these hand postures constituted 15% of all hand contacts. Some of these "non-KW" hand postures have never been documented in gorillas, yet match hand postures previously identified in orangutans.
Discussion:
These results highlight a previously unrecognized level of hand postural diversity in gorillas, and perhaps great apes generally. Although present at lower frequencies than KW, we suggest that the possession of multiple, versatile hand postures present in wild mountain gorillas may represent a shared feature of the African ape and human clade (or even great ape clade) rather than KW per se.
Phalangeal curvature is a term describing the presence of convex curvature along the dorsal surface of manual and pedal phalanges. In extant primates, phalangeal curvature is most pronounced in species that engage in high frequencies of arboreal locomotion. For this reason, it has long been used to infer climbing behaviors in fossil primates. This association is supported by research that suggests phalangeal curvature lowers the forces experienced by digits during grasping. The interpretation of phalangeal curvature as a trait indicative of climbing has contributed to long-standing debates regarding the locomotion of well-known fossil hominids. However, proper application of this feature towards interpreting fossil behavior relies on determining if it is a plastic or inherited trait, which is still being explored.
Pierolapithecus is a Miocene hominoid genus, represented by a single species, Pierolapithecus catalaunicus, dated to 12 million years ago, which provides the oldest comprehensive evidence of the origin of the distinctive orthograde body plan of extant great apes. Morphological features of the trunk, hand, and hindlimb are functionally related to the use of erect trunk postures during climbing and clambering, basic adaptations of extant hominoids. However, in contrast to them, some features, in particular the short hands, suggest that Pierolapithecus lacks below-branch suspensory adaptations. Pierolapithecus thus displays a locomotor pattern with no modern analog, retaining morphologically primitive features related to above-branch, powerful palmigrady, associated with crown hominoid climbing adaptations. The very thick enamel and the analysis of the dental wear marks suggest a diet based on hard foods, similar to that of extant orangutans.
More than ten years of paleontological fieldwork during the enlargement of the Can Mata Landfill (Abocador de Can Mata [ACM]), in els Hostalets de Pierola (Vallès-Penedès Basin, NE Iberian Peninsula) led to the recovery of >60,000 Miocene vertebrate remains. The huge sampling effort (due to continuous surveillance of heavy machinery digging activity, coupled with manual excavation and screen-washing of sediments) enabled generally rare faunal elements such as pliopithecoid and hominoid primates to be found. Thanks to detailed litho-, bio- and magnetostratigraphic controls, accurate dating is possible for all the recovered primate remains from 19 of the 235 localities defined along the 234 m-thick composite stratigraphic sequence of the ACM. Here we report updated estimated (interpolated) ages for these paleontological localities and review the timing of the primate succession in this area. Our results indicate that the whole ACM sequence is late Aragonian in age (MN6 and MN7+8) and includes seven magnetozones that are correlated to subchrons C5Ar.1r to C5r.2r (ca. 12.6 to 11.4 Ma). Great apes (dryopithecines) are first recorded at 12.4–12.3 Ma, but most of the finds (Anoiapithecus, Pierolapithecus and Dryopithecus) cluster between 12.0 and 11.9 Ma, followed by some indeterminate dryopithecine remains between 11.7 and 11.6 Ma. Pliopithecoids first appear at 12.1 Ma, being subsequently represented by Pliopithecus between 11.9 and 11.7 Ma. The small-bodied hominoid Pliobates is the youngest ACM primate, with an estimated age of 11.6 Ma. Although these primates probably overlapped in time, their co-occurrence is recorded only twice, at 11.9 Ma (a dryopithecine with Pliopithecus) and at 11.6 Ma (a dryopithecine with Pliobates). The rare co-occurrence between great apes and small-bodied catarrhines might be attributable to sampling biases and/or to presumed diverging ecological preferences of these groups. In the future, more detailed analyses of the fauna recovered from the long and densely-sampled ACM sequence will hopefully throw new light on this long-standing, unresolved question.
Skeletal functional morphology in primates underlies many fossil interpretations. Understanding the functional correlates of arboreal grasping is central to identifying locomotor signatures in extinct primates. We tested 3 predictions linking substrate orientation and digital grasping pressures: (1) below-branch pressures are greater than above-branch and vertical-branch pressures; (2) there is no difference in pressure exerted across digits within autopods at any substrate orientation, and (3) there is no difference in pressure exerted between homologous digits across autopods at any substrate orientation. Adult males and females from 3 strepsirrhine species crossed an artificial arboreal substrate oriented for above-, below- and vertical-branch locomotion. We compared digital pressures within and across behaviors via ANOVA and Tukey's Honest Significant Difference test. Results show limited support for all predictions: below-branch pressures exceeded vertical-branch pressures and above-branch pressures for some digits and species (prediction 1), lateral digits often exerted greater pressures than medial digits (prediction 2), and pedal digits occasionally exerted greater pressures than manual digits during above-branch and vertical orientations but less often for below-branch locomotion (prediction 3). We observed functional variability across autopods, substrate and species that could underlie morphological variation within and across primates. Future work should consider the complexity of arboreality when inferring locomotor modes in fossils.
Torso-orthograde (TO)-positional behavior
and an associated suite of postcranial morphological specializations
, both of which are often linked to the evolution of large body size
, are considered hallmarks of hominoid evolution
. These features are thought to have played an important role in the Old World monkey-ape divergence and the development of upright bipedal locomotion
in our own lineage. Compared to early theorists, who considered hylobatids an appropriate model for investigating the initial stages of hominoid evolution, more recent reconstructions of the last common ancestor of hominoids
have advocated a larger-bodied, more generalized ape very different from hylobatids as the most likely morphotype. While field observations from the large-bodied non-human hominids (i.e., Asian and African apes) confirm that they do in fact utilize an expansive TO-positional repertoire, no detailed data from hylobatids has been available until now to fully evaluate this hypothesis in light of all hominoid taxa. Using recently published positional behavior data from a population of adult white-handed
gibbons
(
Hylobates lar
) from Khao Yai National Park
, Thailand
, and integrating these data with a diverse anthropoid primate comparative sample, we reevaluate differences in positional behavior of extant cercopithecoids
and hominoids. The comparative dataset agrees with recent suggestions that all living apes share a diverse TO-positional repertoire, relative to that of cercopithecoid monkeys. The question, whether or not TO-anatomical specializations and behavior among the Hominoidea represent homologous or homoplastic traits or both, could not yet be answered conclusively, despite the fact that homologous evolution is the more parsimonious explanation, due to a lack of support from the fossil record. Nevertheless, an upright (TO) and enhanced exploitation of the arboreal tree canopy
by our ape ancestors were likely key evolutionary novelties that helped to shape the origin of hominins. Only an expansive understanding of the diversity of both extant and extinct apes
will help to comprehensively unravel our enigmatic origins.
In the early 20th century the dominant paradigm for the ecological context of the origins of human bipedalism was arboreal suspension. In the 1960s, however, with recognition of the close genetic relationship of humans, chimpanzees and bonobos, and with the first field studies of mountain gorillas and common chimpanzees, it was assumed that locomotion similar to that of common chimpanzees and mountain gorillas, which appeared to be dominated by terrestrial knuckle-walking, must have given rise to human bipedality. This paradigm has been popular, if not universally dominant, until very recently. However, evidence that neither the knuckle-walking or vertical climbing of these apes is mechanically similar to human bipedalism, as well as the hand-assisted bipedality and orthograde clambering of orang-utans, has cast doubt on this paradigm. It now appears that the dominance of terrestrial knuckle-walking in mountain gorillas is an artefact seen only in the extremes of their range, and that both mountain and lowland gorillas have a generalized orthogrady similar to that seen in orang-utans. These data, together with evidence for continued arboreal competence in humans, mesh well with an increasing weight of fossil evidence suggesting that a mix of orang-utan and gorilla-like arboreal locomotion and upright terrestrial bipedalism characterized most australopiths. The late split date of the panins, corresponding to dates for separation of Homo and Australopithecus, leads to the speculation that competition with chimpanzees, as appears to exist today with gorillas, may have driven ecological changes in hominins and perhaps cladogenesis. However, selection for ecological plasticity and morphological conservatism is a core characteristic of Hominidae as a whole, including Hominini.
Almost a century and a half ago, Charles Darwin in The Descent of Man (1871: 141) highlighted the evolution of bipedalism as one of the key features of the human lineage, freeing the hands for carrying and for using and making tools. But how did it arise? The famous footprints from Laetoli in Tanzania show that hominin ancestors were walking upright by at least 3.65 million years ago. Recent work, however, suggests a much earlier origin for bipedalism, in a Miocene primate ancestor that was still predominantly tree-dwelling. Here Susannah Thorpe, Juliet McClymont and Robin Crompton set out the evidence for that hypothesis and reject the notion that the common ancestor of great apes and humans was a knuckle-walking terrestrial species, as are gorillas and chimpanzees today. The article is followed by a series of comments, rounded off by a reply from the authors.
Images in paleoanthropology are of persuasive power, since they try to illuminate ancient life which is not otherwise visually documented. The scientific community, as well as public media and museums, aim to establish a window into the past in part through visualization of scenarios from prehistoric life and environments. The role of human ancestors in these settings is captured by body and especially facial reconstructions, which comparatively easily attract attention among nonscientific audiences and therefore raise public understanding of a complex field of research, allowing it to compete successfully with other, at times more tangible scientific subjects. Within the scientific community itself, reconstructions of early hominids play only a limited role, merely supplementing a whole range of field and laboratory research, evolutionary hypotheses, and the analysis of empirical data. Paleoanthropologists and paleontologists are aware of the interpretative character of facial reconstructions that go beyond the limited set of primary facts documented in the fossils themselves.
The visual approach to paleoanthropology has changed strongly over time, varies with the media used, and depends on how we imagine our ancestors in coeval context. On the one hand, evolutionary theories and contemporary social ideas are influencing and shaping how we view and depict our ancestors. On the other hand, hominid reconstructions themselves, in turn, can influence our view and the underlying ideas.
This chapter reflects on the development of facial reconstructions over time, along with influences such as the development of methods and techniques – from drawings to manual modeling to virtual 3D reconstructions. For exemplification, special emphasis will be put on Neanderthal reconstructions, as these are linked both to early attempts at facial reconstruction and to the subsequent methodological development of reconstruction techniques during the twentieth century. Starting with the first hominid fossils found, we trace the “evolution” of facial reconstructions of Neanderthals, in order to highlight contemporary perceptions and limiting factors in the visualization of our ancestors.
Human hands are distinguished from apes by possessing longer thumbs relative to fingers. However, this simple ape-human dichotomy fails to provide an adequate framework for testing competing hypotheses of human evolution and for reconstructing the morphology of the last common ancestor (LCA) of humans and chimpanzees. We inspect human and ape hand-length proportions using phylogenetically informed morphometric analyses and test alternative models of evolution along the anthropoid tree of life, including fossils like the plesiomorphic ape Proconsul heseloni and the hominins Ardipithecus ramidus and Australopithecus sediba. Our results reveal high levels of hand disparity among modern hominoids, which are explained by different evolutionary processes: autapomorphic evolution in hylobatids (extreme digital and thumb elongation), convergent adaptation between chimpanzees and orangutans (digital elongation) and comparatively little change in gorillas and hominins. The human (and australopith) high thumb-to-digits ratio required little change since the LCA, and was acquired convergently with other highly dexterous anthropoids.
The fossil remains of nine individuals attributable to the Miocene hominoid genus Proconsul were recovered during 1984 and 1985 from the Kaswanga Primate Site on Rusinga Island, Kenya. Among the thousands of bone fragments recovered were hundreds of phalangeal fragments, which have been collected and assembled into 247 separate identifiable phalanges or phalangeal fragments, representing nine of ten identified Kaswanga individuals. This sample is many times larger than any other Miocene hominoid phalangeal sample, and preserves several examples of every hand and foot phalanx from both sexes (deduced from associated cranial remains) in several age categories. This allows for a much greater understanding of normal ranges of variation and for a more detailed reconstruction of positional behavior in Proconsul.
Hominoids, or taxa identified as hominoids, are known from much of Africa, Asia, and Europe since the Late Oligocene. The
earliest taxa, from Africa, resemble extant hominoids but share with them mainly primitive characters. Middle and Late Miocene
taxa are clearly hominoids, and by the end of the Middle Miocene most can be attributed to either the pongine (Pongo) or hominine (African ape and human) clade. Interestingly, there is no fossil record of the hylobatid clade (gibbons and
siamangs). Miocene hominoids experienced a series of dispersals between Africa, Europe, and Asia that mirror those experienced
by many other contemporaneous land mammals. These intercontinental movements were made possible by the appearance of land
bridges, changes in regional and global climatic conditions, and evolutionary innovations. Most of the attributes that define
the hominids evolved in the expansive subtropical zone that was much of Eurasia. Hominines and pongines diverge from each
other in Eurasia, and the final Miocene dispersal brings the hominine clade to Africa and the pongine clade to Southeast Asia.
Having moved south with the retreating subtropics, hominines and pongines finally diverge in situ into their individual extant lineages.
An insightful new work, Function, Phylogeny, and Fossils integrates two practices in paleobiology which are often separated - functional and phylogenetic analysis. The book summarizes the evidence on paleoenvironments at the most important Miocene hominoid sites and relates it to the pertinent fossil record. The contributors present the most up-to-date statements on the functional anatomy and likely behavior of the best known hominoids of this crucial period of ape and human evolution. A key feature is a comprehensive table listing 240 characteristics among 13 genera of living and extinct hominoids.
It is not the purpose of this chapter to provide definitive answers to any of the questions asked in its title, even though various aspects of these questions have formed a large part of the lively debate that has been conducted in recent years concerning Miocene hominoid postcrania. The material available for investigation has been increased significantly recently by new specimens from the early Miocene of East Africa [KNM-RU 2036C and KNM-RU 5872 specimens (Walker and Pickford, this volume, Chapter 12)], the later Miocene of Rudabánya, Hungary [Rud specimens (Morbeck, this volume, Chapter 14)], and the Potwar Plateau of Pakistan [most GSP specimens (Pilbeam et al., 1980)]. The main purpose of this chapter is to make some general comments on functional features of the morphology of some Miocene hominoid postcrania and on possible positional capabilities consistent with those features. Similarities to and differences from features of Miocene species evident in the postcrania of groups of living higher primates will be made purely in terms of function. Attention will be directed toward the larger bodied Miocene hominoids. Original specimens of all the East African and Asian material have been examined. The European material has been examined in cast form.
A renaissance of comparative primatological studies occurred during the past 15 years. It flourishes unabated. It is characterized by intensive focuses on function and inferential phylogenies and a dazzling battery of new and refurbished gadgetry and methods ranging from electromyography and cineradiography to computers and multivariate statistics for many seasons. This, coupled with an outpouring of information on the behavior of captive and free-ranging primates, their biomolecular particularities, and a remarkable number of new fossils, promises to elucidate aspects of some primate careers in a refreshingly solid note. Hopefully man will be among this newly illuminated lot.
This brief commentary begins with my graduate work with Elwyn Simons which culminated in the 1965 “Preliminary Revision of the Dryopithecinae,” then about the most comprehensive review of the paleontological record of the great apes (Simons and Pilbeam, 1965). It reflected a time when that fossil record was dominated by teeth and fragmentary jaws, one decent skull, and a handful of postcranial remains. Much has changed since then, both in the record itself and in how it is interpreted, and what follows are reflections on where we are, how we got here, and where we might go next.
During the last 10 years numerical methods have begun to dominate paleontology. These methods now reach far beyond the fields of morphological and phylogenetic analyses to embrace biostratigraphy, paleobiogeography, and paleoecology. Paleontological Data Analysis explains the key numerical techniques in paleontology, and the methodologies employed in the software packages now available. Following an introduction to numerical methodologies in paleontology, and to univariate and multivariate techniques (including inferential testing), there follow chapters on morphometrics, phylogenetic analysis, paleobiogeography and paleoecology, time series analysis, and quantitative biostratigraphy Each chapter describes a range of techniques in detail, with worked examples, illustrations, and appropriate case histories Describes the purpose, type of data required, functionality, and implementation of each technique, together with notes of caution where appropriate The book and the accompanying PAST software package (seewww.blackwellpublishing.com/hammer) are important investigative tools in a rapidly developing field characterized by many exciting new discoveries and innovative techniques An invaluable tool for all students and researchers involved in quantitative paleontology.
Comparative morphology of the African ape hand is receiving renewed interest in the wake of recent discoveries of fossil hominid hands and the increasing number of biomolecular studies that question the traditional chimpanzee/gorilla clade. This paper compares ontogenetic sequences of Pan paniscus, Pan troglodytes troglodytes, Gorilla gorilla gorilla, Gorilla gorilla beringei and Pongo pygmaeus in order to assess whether or not previously established interspecific differences between adult chimpanzee and gorilla metacarpals and phalanges are due to a differential extension/truncation of a common growth allometry. Furthermore, inter-ray comparisons are made within the African apes to evaluate the functional role of individual rays. Results indicate that most dimensions of metacarpals and phalanges are ontogenetically scaled between Pan and Gorilla and also among pongids. Metacarpal and phalangeal lengths, however, depart from the general pattern of ontogenetic scaling. In interspecific comparisons of metacarpal and phalangeal lengths regressed on public lengths, the slopes are not significantly different between chimpanzees and gorillas, but there are significant transpositions in the growth trajectories such that Gorilla has shorter rays than Pan at common sizes. Inter-ray comparisons between genera reveal that gorillas have less variation between rays in almost all dimensions compared to chimpanzees. On the basis of these results, it is concluded that most differences in metacarpal, phalangeal, and inter-ray morphology between chimpanzees and gorillas that are not attributed to ontogenetic scaling may be related to the following: (1) kinematically distinct types of knuckle-walking, (2) a greater proportion of body weight borne on the hands of gorillas than chimpanzees at common sizes, or (3) a higher frequency of arboreal behavior of chimpanzees than gorillas at common sizes.
Extreme reduction of the hallux is unique to the orang-utan (Pongo pygmaeus) among Primates. Hallucal diminution has advanced so far that 60% of orang-utans lack both distal phalanges and nails. Absence of these structures occurs significantly more often in females than in males. Hypotheses on possible genetic control of the condition have been tested and indicate that either single gene inheritance or polygenic inheritance with variable expressivity is involved. Reduction of pollex and of hallux in Pongo have advanced with selection for a specialized four-digit grasp in hands and feet. Diminution has progressed farther in the great toe than in the thumb due to selection for fine manipulation in the latter digit.
IN 1856 Éduard Lartet described a hominoid humerus which had been found at the same time and place as the type mandibular fragments of Dryopithecus fontani
1. This was the first recording of a fossil great ape. The site of this classic find was a brickworks in Miocene marly clays at the base of a wooded hill or plateau on which the village of Saint Gaudens (Haute Garonne), France, is situated.
Numerous studies of the locomotor skeleton of the Hadar hominids have revealed traits indicative of both arboreal climbing/suspension and terrestrial bipedalism. These earliest known hominids must have devoted part of their activities to feeding, sleeping and/or predator avoidance in trees, while also spending time on the ground where they moved bipedally. In this paper we offer new data on phalangeal length and curvature, moφhology of the tarsus and metatarsophalangeal joints, and body proportions that further strengthen the argument for arboreality in the Hadar hominids. We also provide additional evidence on limb and pedal proportions and on the functional anatomy of the hip, knee and foot, indicating that the bipedality practiced at Hadar differed from that of modern humans. Consideration of the ecology at Hadar, in conjunction with modern primate models, supports the notion of arboreality in these earliest australopithecines. We speculate that selection for terrestrial bipedality may have intensified through the Plio-Pleistocene as forests and woodland patches shrunk and the need arose to move increasingly longer distances on the ground. Only with Homo erectus might body size, culture and other factors have combined to ‘release’ hominids from their dependence on trees.
Many problems in comparative biology and biological anthropology require meaningful definitions of “relative size” and “shape.” Here we review the distinguishing features of ratios and residuals and their relationships to other methods of “size-adjustment” for continuous data. Eleven statistical techniques are evaluated in reference to one broadly interspecific data set (craniometries of adult Old World monkeys) and one narrowly intraspecific data set (anthropometries of adult Native American males). Three different types of residuals are compared to three versions of shape ratios, and these are contrasted to “cscores,” Penrose shape, and multivariate adjustments based on the first principal component of the logged variance-covariance matrix; all methods are also compared to raw and logged raw data. In order to help us identify appropriate; methods for size-adjustment, geometrically similar or “isometric” versions of the male vervet and the Inuit male were created by scalar multiplication of all variables. The geometric mean of all variables is used as overall “size” throughout this investigation, but our conclusions would be the same for most other size variables.
The fossil hominid hand bone collection from the Pliocene Hadar Formation, Ethiopia, is described anatomically. These hand bones, all from A.L. (Afar Locality) 333 and 333w, constitute the largest sample of hominid manus remains thus far recovered from the Plio-Pleistocene of Africa.
Comparative morphology has long been vexed by conflicting considerations of size and shape (relative size); a subsidiary consideration has been the effect of allometry (shape change with size) on results and interpretations.
A review of history and opinion indicates the lack of universal acceptance of the following points: the inherent relatedness and/or separability of size and shape; the greater importance (anatomically, functionally, and/or taxonomically) of shape than size; the existence of residual size effects (allometry) after canceling the gross linear size factor from morphometric data; the failure of covariance matrix inversion to negate size always; the dimensionless quality of shape variables; the effect of logarithmic transformation; and the inadvisability of simple ratios.
Two morphometric data sets (primate postcranial proportions, hominoid maxillary premolar odontometrics) encompassing significant size and taxonomic diversity in primates enable illustration and examination of these points.
Although determination of optimum procedures is problematic, accuracy of classification and partition of variance among known morphogroups are criteria that can be applied. Intergroup distances generated after inversion of the covariance matrix show little improvement over raw size distances, unlike the shape distances expressed by shape vector (ratio), double-centered, Penrose, common part removed, and Q-mode correlation methods; very slight further improvement is accomplished using pooled within-group adjustment to remove residual size (allometric) effects. No improvement emanates solely from log transformation of measurements. Significant problems are indicated by the results obtained with interspecific regression residuals: particularly, large and small forms in the analysis become unrealistically similar. Also, regression-corrected distances still correlate with size even though the univariate residual values, by definition, do not.
Comparisons of hominoid metacarpals and phalanges reveal differences, many of which are closely linked to locomotor hand postures. The African apes display features of the metacarpals and phalanges which distinguish them from the other Hominoidea. These features are most evident in digits III and IV. The orangutan hand is demonstrably less well adapted to knuckle-walking and is distinctive in its adaptation to power and hook grasping of vertical and horizontal supports, respectively. Orangutan fingers possess a “double-locking” mechanism (Napier, '60), and a slight ulnad shift in the axis of the hand which results in lengthened phalanges of ray IV. Hylobatid apes are more like orangutans in their finger morphology than any of the other Hominoidea, but exhibit unique features of their own. These include elongate phalanges of fingers II-V. Human metacarpals II-V form two sets composed of II-III, and IV-V. The heads of both metacarpals II and III are characterized by axial torsion. This reflects the enhanced manipulatory role of the third finger in humans. Human distal phalanges are unique in the development of pronounced apical tufts.
Multivariate analysis of metacarpal III and proximal III yields variables that array the extant apes along an arboreal-terrestrial axis, from hylobatid apes to male gorillas. The positions of taxa on this discriminant concur with observations on the locomotion of free-ranging apes.
Extant apes are adapted to various forms of below-branch forelimb-dominated arboreal locomotion and share morphologies associated
with the shared aspects of their locomotor behaviors. With the expanding record of Miocene hominoid fossils, we are coming
to realize that although some shared characters may indeed be homologous, at least some almost certainly represent homoplasies.
The apparently more primitive body plan of Sivapithecus than seen in Asian and African great apes indicates that at least some homoplasy has occurred within these clades. Furthermore,
the expanding fossil record may be indicating a greater diversity of positional behaviors within the Hominoidea than previously
appreciated; for example, Pierolapithecus may indicate the evolution of suspensory locomotion in combination with arboreal quadrupedalism, and Nacholapithecus is unique with its enlarged forelimb but otherwise primitive body plan. These new fossils reveal that variation is prevalent
and critical to appreciate for reconstructing hominoid evolutionary history. Furthermore, it seems increasingly likely that
many postcranial and locomotor specializations of great apes may have evolved from ancestors that were more generalized than
are living hominoids. This realization is critical for interpreting the ancestral morphology from which hominins were derived.
Despite the large and growing number of Miocene fossil catarrhine taxa, suitable common ancestors of great apes and humans
have yet to be agreed upon. Considering a) the conservative and primitive nature of the hominoid molar cusp pattern, and b)
the variability of secondary dental features, it is difficult to discern whether a hominoid dentition is primitive, secondarily
simplified to the primitive condition or too far derived to be ancestral to any of the living forms. Nonetheless, the inability
to recognize a common ancestor is primarly due to the absence of a model of hominoid differentiation that provides a basis
for its recognition. Vertical climbing as the limiting component of cautious climbing, explains all of the locomotor anatomy
shared by living hominoids. Comparison of the shared derived characters of hominoids to those of forms which have converged
on hominoidsi.e colobines, atelines, lorisines, paleopropithecines and sloths suggest that early hominoids were probably folivores. In arboreal
forms there is a strong link between a large body size, folivory and cautious climbing. Comparison of craniodental characters
of committed folivores to committed frugivores from among each of the compared groups with the exception of lorisines, indicates
that many of the distinguishing craniodental characters of humans and great apes are adaptations to folivory. Many of these
characters, however, are also present in Jolly's seed eating complex. As such folivory may be the heritage factor which Jolly
hypothesized to account for differential reduction of canines in fossilTheropithecus and hominids.
Observations on the behavior of living hominoids show generic differences in the use and posture of the wrist joint. Both
orang-utans and hylobatids usually use the wrist in suspensory behaviors. However, orang-utans emphasize markedly adducted
and flexed wrist postures, while hylobatids emphasize violent forearm and wrist rotation. African apes, especially the gorilla,
use the wrist more frequently than other hominoids for terrestrial quadrupedal weight-bearing. Humans use the wrist less frequently
for supportive purposes than do other hominoids. These behavioral differences correspond to structural specializations in
the proximal carpal joint of each of the hominoid genera. Although each of the hominoid genera has apparently modified its
proximal carpal joint best to serve its characteristic behaviors, all hominoids share a unique proximal carpal joint that
permits approximately 160ℴ of forearm rotation. The hylobatid proximal carpal joint is specialized in exhibiting a marked
development of those structures limiting forearm rotation, but it is in most respects the least derived— that is, closest
to the nonhominoid anthropoids. Chimpanzees show a proximal carpal joint that is more generalized than those of the other
great apes but more derived than that of hylobatids. The human and gorilla proximal wrist joints, on the other hand, show
marked modifications for weight-bearing in terrestrial behaviors. Orang-utans have the most derived proximal carpal joint,
which in many respects parallels that of the slow-climbing nonhominoid primates. The comparative anatomy and structural specializations
of the wrist joint support (a) an early divergence of hylobatids from the common hominoid stock, (b) a common ancestry for
gorillas and humans separate from the other hominoids, and (c) a long independent evolutionary period for orang-utans since
their divergence from the common hominoid stock, or one that was marked by strong selection pressures for wrist specializations.
Unfortunately, the generalized condition of the chimpanzee’s wrist joint and the very derived condition of the orang-utan
wrist provide uncertain evidence as to which of the two was first to diverge from the common hominoid stock. Identification
of hominoid wrist specializations as reflecting real phylogenetic relationships or parallelisms depends on how well the phytogeny
inferred from wrist morphology accords with those arrived at from the study of other systems.
Two calcanei, a cuboid, and three manual phalanges of Late Miocene Sivapithecus from Pakistan are described. The morphology of the foot bones suggests that considerable rotation around the long axis of the foot resulted from movements at the subtalar and transverse tarsal joints. This was accompanied by other movements at the subtalar joint. Articular features of the phalanges are similar to those of palmigrade quadrupeds. However, features of shaft curvature and robusticity imply that the fingers were also subjected to tensile stresses. The combined evidence of these and previously described specimens suggests that arboreal quadrupedalism and climbing were distinctive features of Sivapithecus positional behavior.
Proximal phalanges recovered from Oligocene sediments of the Jebel Qatrani Formation, Fayum Province, Egypt, are attributed to the anthropoids Aegyptopithecus and Apidium. A multivariate discriminant function analysis using phalangeal shape indices proved reliable for distinguishing between manual and pedal proximal phalanges of extant primates, and these data can be applied to classify phalanges of fossil primates. Manual and pedal phalanges of Aegyptopithecus show features clearly related to a quadrupedal arboreal lifestyle involving frequent and powerful digital flexion: plantar tubercles are prominent, the flexor sheath ridges are well developed, shaft height increases proximally, shaft cortices are thickest in their distal halves, and the phalanges display strong dorsoventral curvature. Proximal phalanges of Aegyptopithecus resemble those of extant Alouatta, and to a lesser extent those of colobine primates, in these respects. These fossil phalangeal specimens resemble quadrupedal cercopithecids in having large palmar and plantar tubercles, flaring basal apophyses, robust shafts, and dorsally extended and proximodorsally tilted metacarpal and metatarsal facets. Manual and pedal phalanges of Apidium have straight, robust shafts with cortices of equal thickness throughout, relatively dorsoventrally compressed condyles, weak flexor ridges, and a flared base for insertion of the collateral ligaments and interosseous musculature. These features suggest a locomotor repertoire for Apidium that is well suited for stable digital extension during quadrupedal running on horizontal substrates with little emphasis on grasping capabilities. These features compare most favourably with those of the phalanges of extant Saimiri.
Recent collections at the middle Miocene site of Maboko Island in Kenya have yielded a relatively large sample of isolated postcranial bones that can be assigned with some degree of confidence to the early cercopithecid. Victoriapithecus. This paper provides a detailed description of the postcranial morphology of Victoriapithecus, and offers some general conclusions concerning its inferred locomotor behavior and phylogenetic status. The range of metrical and morphological variation exhibited by the material does not exceed that seen in modern species of Old World monkeys. This findings is consistent with recent re-interpretations of the cranio-dental material that indicate that only a single species of Victoriapithecus may be represented at Maboko Island. Victoriapithecus appears to be a relatively small (with an estimated average body weight of 3·5–4·0 kg), agile and active quadrupedal monkey, adapted to moving effectively in both arboreal and terrestrial settings. In its overall morphology, and probably also in its inferred locomotor behavior. Victoriapithecus is most closely similar to modern-day semi-terrestrial Old World monkeys.
Adaptation has been defined and recognized by two different criteria: historical genesis (features built by natural selection for their present role) and current utility (features now enhancing fitness no matter how they arose). Biologists have often failed to recognize the potential confusion between these different definitions because we have tended to view natural selection as so dominant among evolutionary mechanisms that historical process and current product become one. Yet if many features of organisms are non-adapted, but available for useful cooptation in descendants, then an important concept has no name in our lexicon (and unnamed ideas generally remain unconsidered): features that now enhance fitness but were not built by natural selection for their current role. We propose that such features be called
exaptations
and that adaptation be restricted, as Darwin suggested, to features built by selection for their current role. We present several examples of exaptation, indicating where a failure to conceptualize such an idea limited the range of hypotheses previously available. We explore several consequences of exaptation and propose a terminological solution to the problem of preadaptation.
Fossil hominoid remains from the Miocene site of Moroto II include a well preserved lumbar vertebra (UMP 67-28). This vertebra is associated with a palate that has been included in the hominoid tribe Afropithecini and referred by some to Afropithecus. UMP 67-28 originally was described as having close morphological affinities with lumbar vertebrae from African apes and humans (Walker & Rose, 1968). The present analysis, however, indicates that UMP 67-28 shares no exclusive proportional or structural similarities with lumbar vertebrae from any particular extant catarrhine. The Moroto vertebra is the size of lumbar elements from female chimpanzees and orang-utans or large male cercopithecoids. Regression analysis of vertebral body surface area suggests that the individual represented by UMP 67-28 had a body weight of approximately 38 kg. UMP 67-28 is similar to large-bodied hominoids in general, in position and orientation of its transverse process, absence of anapophyses, inclination of its neural spine, and pedicular shape, marking the earliest appearance in the catarrhine fossil record of lumbar morphology resembling that of modern hominoids. Conversely, vertebral body proportions in UMP 67-28 most closely resemble those in male baboons, and in other traits the specimen cannot be differentiated between hominoids and cercopithecoids. The overall morphology of UMP 67-28 indicates that lumbar vertebrae of the Moroto hominoid were mole derived toward the great ape condition than those of Proconsul heseloni and P. nyanzae. In contrast to Proconsul, UMP 67-28 shares features with other dorsostable-backed mammals, suggesting that the Moroto hominoid and Proconsul possessed very different locomotor capabilities. Dental traits linking the Moroto hominoid with other afropithecins are thought to correspond functionally to a fundamental shift in diet, relative to the primitive catarrhine condition. It is possible that evolution of the lumbar region of early hominoids toward the morphotype of extant large-bodied hominoids, evidenced in UMP 67-28, was adaptively driven by modifications in substrate use coincident with changes in resource acquisition. Peer Reviewed http://deepblue.lib.umich.edu/bitstream/2027.42/31743/1/0000682.pdf
A well-preserved 11.8-million-years-old lower face attributed to the seminal taxon Dryopithecus fontani (Primates, Hominidae) from the Catalan site ACM/C3-Ae of the Hostalets de Pierola area (Vallès-Penedès Basin, Catalonia, NE Spain) is described. The new data indicate that D. fontani is distinct at the genus level from Late Miocene European taxa previously attributed to Dryopithecus, which are here reassigned to Hispanopithecus. The new facial specimen also suggests that D. fontani and the Middle Miocene Pierolapithecus catalaunicus are not synonymous. Anatomical and morphometric analyses further indicate that the new specimen shows a combination of lower facial features-hitherto unknown in Miocene hominoids-that resembles the facial pattern of Gorilla, thus providing the first nondental evidence of gorilla-like lower facial morphology in the fossil record. Considering the current evidence, the gorilla-like facial pattern of D. fontani is inferred to be derived relative to previously known stem hominids, and might indicate that this taxon is either an early member of the Homininae or, alternatively, a stem hominid convergent with the lower facial pattern of Gorilla. The biogeographic implications of both alternatives are discussed. This new finding in the Hostalets de Pierola section reinforces the importance of this area for understanding the elusive question of the Middle Miocene origin and early radiation of great apes.
Phalangeal curvature has frequently been used as a proxy indicator of fossil hominoid and hominin positional behavior and locomotor adaptations, both independently and within the context of broader discussions of the postcranium as a whole. This study used high-resolution polynomial curve fitting (HR-PCF) to measure the shaft curvature of fragmentary proximal phalanges that have previously been excluded from analyses of phalangeal curvature owing to design limitations of existing methods. In doing so, the available sample of fossil specimens was increased substantially, making it possible to test prevailing locomotor hypotheses for many taxa with new specimens. The results generated from the HR-PCF analysis of extant primate manual and pedal phalangeal samples suggest that, although capable of identifying suspensory hominoids with some degree of accuracy, phalangeal curvature values reported for extant terrestrial and arboreal quadrupeds overlap considerably. Consequently, it is difficult to reliably predict the locomotor adaptations for fossil taxa with phalangeal curvatures similar to these groups, although the curvature values reported for most taxa were broadly consistent with existing locomotor hypotheses. Only the curvature values reported for Pierolapithecus, which are most similar to those of suspensory hominoids, are inconsistent with previously published locomotor hypotheses. Likewise, although not inconsistent with bipedality, curvature values reported for Australopithecus confirm earlier conclusions that, despite a general reduction in phalangeal length relative to Pan, these taxa have similar and overlapping ranges of phalangeal curvature.
Allometry should be defined broadly as the study of size and its consequences, not narrowly as the application of power functions to the data of growth. Variation in size may be ontogenetic, static or phyletic. Errors of omission and treatment have plagued the study of allometry in primates. Standard texts often treat brain size as an independent measure, ignoring its allometric relation with body size - on this basis, gracile australopithecines have been accorded the mental status of gorillas. Intrinsic allometries of the brain/body are likewise neglected: many authors cite cerebral folding as evidence of man's mental superiority, but folding is a mechanical correlate of brain size itself. Confusion among types of scaling heads errors of treatment in both historical primacy [Dubois' ontogenetic inferences from interspecific curves] and current frequency. The predicted parameters of brain-body plots differ greatly for ontogenetic, intrapopulational, interspecific and phyletic allometries. I then discuss basic trends in bivariate allometry at the ordinal level for internal organ weights, skeletal dimensions, lifespan and fetal weight. In considering the causes of basic bivariate allometries, I examine the reason for differences among types of scaling in brain-body relationships. The interspecific exponent of 0.66 strongly suggests a relationship to body surfaces, but we have no satisfactory explanation for why this should be so. The tripartite ontogenetic plot is a consequence of patterns in neuronal differentiation. We do not know why intraspecific exponents fall between 0.2 and 0.4; several partial explanations have been offered. Multivariate techniques have transcended the pictorial representation of transformed coordinates and offer new, powerful approaches to total allometric patterns. Allometry is most often used as a 'criterion for subtraction'. In order to assess the nature and purpose of an adaptation, we must be able to identify and isolate the aspect of its form that depends both upon its size and the size of the body within which it resides. Cranial indices and limb lengths are misinterpreted when authors apply no correction for body size. The search for a criterion of subtraction has been most diligently pursued in studies of the brain. Clearly, brain size must be assessed by comparison with a 'standard' animal of the same body size. But how shall size be measured, especially in fossils; and how shall a standard animal be construed. I discuss and criticize three methods recently used: RADINSKY'S foramen magnum criterion; Jerison's minimum convex polygons and cephalization quotients; and the indices of progression in comparison with 'basal' insectivores' of BAUCHOT, Stephan and their colleagues.
A major contribution of previous analyses of Miocene hominoid postcrania is the recognition of a great ape grade of locomotor morphology in the late Miocene. However, in the absence of a consideration of the taxonomic and phylogenetic implications of the specimens concerned, the importance of this conclusion remains unappreciated. This paper presents a revised view of the positional implications of late Miocene hominid fossils and considers some of the taxonomic and phyletic implications of these specimens. The taxonomic status of a number of large catarrhine specimens from Europe (attributed to Dryopithecus, Sivapithecus, Austriacopithecus, Paidopithex, Rudapithecus) is discussed. The functional and phyletic significance of this material reveals a complex pattern of behavioral and phyletic diversity among large-bodied catarrhines in Europe and suggests that this diversity evolved in situ from circum-Mediterranean middle Miocene ancestors.
Mechanical hypotheses concerning the function of chimpanzee anatomical specializations are examined in light of recent positional behavior data. Arm-hanging was the only common chimpanzee positional behavior that required full abduction of the humerus, and vertical climbing was the only distinctive chimpanzee positional behavior that required forceful retraction of the humerus and flexion of the elbow. Some elements of the chimpanzee anatomy, including an abductible humerus, a broad thorax, a cone-shaped torso, and a long, narrow scapula, are hypothesized to be a coadapted functional complex that reduces muscle action and structural fatigue during arm-hanging. Large muscles that retract the humerus (latissimus dorsi and probably sternocostal pectoralis major and posterior deltoid) and flex the elbow (biceps brachii, probably brachialis and brachioradialis) are argued to be adaptations to vertical climbing alone. A large ulnar excursion of the manus and long, curved metacarpals and phalanges are interpreted as adaptations to gripping vertical weight-bearing structures during vertical climbing and arm-hanging. A short torso, an iliac origin of the latissimus dorsi, and large muscles for arm-raising (caudal serratus, teres minor, cranial trapezius, and probably anterior deltoid and clavicular pectoralis major) are interpreted as adaptations to both climbing and unimanual suspension.
New humeri of two species of the Miocene hominoid Sivapithecus are described from near Chinji in Pakistan from between approximately 9 and 11 Myr ago. Sivapithecus, a middle and late Miocene hominoid from Turkey and Indo-Pakistan, is overall unlike any living hominoid, although facial-palatal similarities to the extant orangoutan, Pongo, have been used to support a hypothesis of close relationship. Living hominoids have postcranial similarities assumed to be shared derived, among them features of the proximal humerus. However, the new Sivapithecus proximal humeri differ from those of living hominoids, supporting an alternative hypothesis in which Sivapithecus and Pongo are not closely related. It is not clear how to choose between these incompatible hypotheses.