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Astragalar and calcaneal morphology of the middle Eocene primate Anchomomys frontanyensis (Anchomomyini): Implications for early primate evolution
... The functional morphology of the tarsus has been extensively studied for the calcaneus and astragalus of extinct primates (e.g., Decker and Szalay, 1974;Szalay and Decker, 1974;Lewis, 1980a,b;Godinot and Dagosto, 1983;Dagosto, 1988Dagosto, , 2007Gebo, 1988;Gebo et al., 2000Gebo et al., , 2001Gebo et al., , 2012Gebo et al., , 2015Seiffert and Simons, 2001;Dunn et al., 2006;Dagosto et al., 2010;Dunn, 2010;Marivaux et al., 2010Marivaux et al., , 2011Moy a-Sol a et al., 2012;Boyer et al., 2013Boyer et al., , 2015Boyer et al., , 2017aGladman et al., 2013;Chester et al., 2015;Seiffert et al., 2015;Marig o et al., 2016;Yapuncich et al., 2017Yapuncich et al., , 2019. These two bones account for the 31% and 38% of the fossil primate pedal remains preserved in the fossil record, respectively, indicating a strong bias toward their study compared with other foot elements (Yapuncich et al., 2022). ...
... Evolutionary model 1988; Gebo et al., 1991;Boyer et al., 2013), as supported by our results (Figs. 3e5; Tables 2e4). The only exception is the smallbodied adapiform A. frontanyensis, which possesses an omomyiform-like tarsal elongation (Marig o et al., 2016(Marig o et al., , 2020. This is indicated in the phylomorphospace (Fig. 2), in which A. frontanyensis falls very close to the omomyiform cluster. ...
... Omomyiforms show lower evolutionary rates than adapiforms, which experienced a body size increase that led to the acquisition of a different type of locomotion than the ancestral euprimate, arguably emphasizing above-branch quadrupedalism, as in extant lemurids (Rose and Walker, 1985;Covert, 1988;Gebo et al., 1991). Some adapiforms, such as the small-bodied A. frontanyensis, converged toward the omomyiform condition by displaying a more proximodistally elongated navicular as a result of more active arboreal locomotor behaviors (Marig o et al., 2016(Marig o et al., , 2020. ...
The morphological adaptations of euprimates have been linked to their origin and early evolution in an arboreal environment. However, the ancestral and early locomotor repertoire of this group remains contentious. Although some tarsal bones like the astragalus and the calcaneus have been thoroughly studied, the navicular remains poorly studied despite its potential implications for foot mobility. Here, we evaluate early euprimate locomotion by assessing the shape of the navicular—an important component of the midtarsal region of the foot—using three-dimensional geometric morphometrics in relation to quantified locomotor repertoire in a wide data set of extant primates. We also reconstruct the locomotor repertoire of representatives of the major early primate lineages with a novel phylogenetically informed discriminant analysis and characterize the changes that occurred in the navicular during the archaic primate–euprimate transition. To do so, we included in our study an extensive sample of naviculars (36 specimens) belonging to different species of adapiforms, omomyiforms, and plesiadapiforms. Our results indicate that navicular shape embeds a strong functional signal, allowing us to infer the type of locomotion of extinct primates. We demonstrate that early euprimates displayed a diverse locomotor behavior, although they did not reach the level of specialization of some living forms. Finally, we show that the navicular bone experienced substantial reorganization throughout the archaic primate–euprimate transition, supporting the major functional role of the tarsus during early primate evolution. This study demonstrates that navicular shape can be used as a reliable proxy for primate locomotor behavior. In addition, it sheds light on the diverse locomotor behavior of early primates as well as on the archaic primate–euprimate transition, which involved profound morphological changes within the tarsus, including the navicular bone.
... Functional implications of these features, derived from correlations between morphology and positional behavior in extant primates (Dagosto, 1986;Gebo, 1986aGebo, , b, 1987aGebo, , b, 1988Gebo, , 1989aGebo, , b, 1994, were applied to fossil taxa to better understand the evolution of euprimate positional behavior. These features still serve as core components of the descriptive morphology of euprimate fossils and interpretation of posture and locomotion (e.g., Rose et al., 2011;Dunn et al., 2016;Marigó et al., 2016Marigó et al., , 2020. ...
... Preserved in two shale slabs, the skeleton of the middle Eocene cercamoniine Darwinius masillae from Grube Messel, Germany, provides excellent documentation of relative proportions of the foot and digits (although comparisons that rely on 3D measurements are more challenging) (Franzen et al., 2009). Tarsals of Donrussellia, a dentally primitive euprimate , and Anchomomys, a small-bodied European adapiform, (Marigó et al., 2016(Marigó et al., , 2020 have also been described. ...
... Finally, pedal features of some adapiform species, including notharctids (Gregory, 1920;Napier & Walker, 1967;Gebo, 1988; but see Gingerich, 2012), Donrussellia , and Anchomomys (Marigó et al., 2016(Marigó et al., , 2020 may reflect leaping specializations. The tali of these taxa have a deep talar body, a strongly developed posterior trochlear shelf, and a shallow flexor fibularis groove. ...
The Paleogene epoch was a dynamic time for mammalian evolution, including the fossil relatives of primates. Several adaptively significant features of the primate foot first appear in fossils from the Paleogene, and relatives of most extant primate groups are recognizable in the fossil record by the end of the Oligocene. This chapter reviews the morphology of the foot in Paleogene fossil groups (plesiadapiforms, adapiforms, omomyiforms, and early anthropoids) and focuses on recently discovered or described fossils to examine four key aspects of primate feet (e.g., hallucial metatarsal morphology, proximal tarsal morphology, digit ray proportions, and degree of pedal prehensility). After discussing the morphology of each fossil group, we compare the order of appearance of these features with predictions made by several adaptive hypotheses for primate origins and make recommendations for future research.
... Measurements of the teeth were taken with an optic caliper "Nikon measuroscope 10" connected to a monitor "Nikon SC112" and using the criteria described by Marig o et al. (2010) and Femenias-Gual et al. (2016b). The measurements on the calcaneus were taken with an optic caliper Electro DH, model 60.205, with a 0.01 mm resolution, following Gladman et al. (2013) andMarig o et al. (2016). ...
... Since the attribution of the fragment of the calcaneus to A. smithorum could be controversial, even though this is the only primate for which dental remains have been recovered in the fossil site of Casa Retjo-1, we plotted calcaneal cuboid facet area against length of the second lower molar (Fig. 1), using comparative data provided by , , and Winchester et al. (2014), in order to check if the size of the calcaneus found matches the expected size for this species, taking into account its molar size (Marig o et al., 2016). ...
... In order to test the phylogenetic relationships of A. smithorum in light of the new findings, we also performed a phylogenetic analysis with the latest version of the character-taxon matrix of living and extinct primates, as well as euarchontan outgroups originally published by Seiffert et al. (2005), including its later modifications (Seiffert et al., 2009;Marig o et al., 2011Marig o et al., , 2013Marig o et al., , 2016Femenias-Gual et al., 2017). We added to the last version of the matrix the scorings provided by the new material of A. smithorum. ...
New material attributed to Agerinia smithorum from Casa Retjo-1 (early Eocene, NE Iberian Peninsula), consisting of 13 isolated teeth and a fragment of calcaneus, is studied in this work. These fossils allow the first description of the calcaneus and the upper premolars for the genus Agerinia, as well as the first description of the P2 and M2 for A. smithorum. The newly recovered lower teeth are virtually identical to the holotype of A. smithorum and are clearly distinguishable from the other species of Agerinia. The upper teeth also show clear differences with Agerinia marandati. The morphology of the calcaneal remains reveals that A. smithorum practiced a moderately active arboreal quadrupedal mode of locomotion, showing less leaping proclivity than notharctines but more than asiadapids. All the morphological features observed in the described material reinforce the hypothesis of a single lineage consisting of the species A. smithorum, A. marandati, and Agerinia roselli. Furthermore, the phylogenetic analysis developed in this work, which incorporates the newly described remains of A. smithorum, maintains the position of Agerinia as closely related to sivaladapids and asiadapids.
... Under this scenario the more generalized anatomy of euprimates from Vastan mine, India would represent specializations that postdate the initial radiation of euprimates from their common ancestor. Slightly earlier occurring notharctid adapiforms from North America (Cantius ralstoni) appear more dentally primitive than Vastan mine adapiforms (Asiadapinae) in certain respects and have a postcranium reflecting more leaping specialization (Rose and Walker, 1985;Boyer et al., 2013a); however, most recent cladistic analyses reconstruct notharctids as more nested than asiadapines (Seiffert et al., 2015;Marig o et al., 2016;Ni et al., 2016). Therefore, for adapiforms, the idea that the earliest members lacked leaping specializations is better supported. ...
... That is, an extension of the lateral tibial facet onto the neck is only a squatting facet if it is also distinctly concave, or sulcus-like. The squatting facet is typical of omomyiforms (Godinot and Dagosto, 1983;Covert and Hamrick, 1993;Dunn et al., 2006) and adapines , but is usually lacking in notharctids Marig o et al., 2016) including species of Cantius and M. indicus. It is also lacking in anthropoids, Eosimias, Vastanomys major, and some plesiadapiforms (Fig. 2). ...
... Indeed, the asiadapines are the only fossil euprimates to plot within the polygon encompassing extant lorises in our analysis of biomechanically important features of the talar body (Fig. 5A). Marig o et al. (2016) concluded that the talus of M. indicus also has features of the neck and head associated with slow climbing (Gebo, , 1989, such as an exceptionally short talar neck, high neck angle and flattened talar head. The strong dorsomedial position of the head also differentiates it from P. lowii, Eosimias and D. provincialis. ...
The fossil record of early primates is largely comprised of dentitions. While teeth can indicate phylogenetic relationships and dietary preferences, they say little about hypotheses pertaining to the positional behavior or substrate preference of the ancestral crown primate. Here we report the discovery of a talus bone of the dentally primitive fossil euprimate Donrussellia provincialis. Our comparisons and analyses indicate that this talus is more primitive than that of other euprimates. It lacks features exclusive to strepsirrhines, like a large medial tibial facet and a sloping fibular facet. It also lacks the medially positioned flexor-fibularis groove of extant haplorhines. In these respects, the talus of D. provincialis comes surprisingly close to that of the pen-tailed treeshrew, Ptilocercus lowii, and extinct plesiadapiforms for which tali are known. However, it differs from P. lowii and is more like other early euprimates in exhibiting an expanded posterior trochlear shelf and deep talar body. In overall form, the bone approximates more leaping reliant euprimates. The phylogenetically basal signal from the new fossil is confirmed with cladistic analyses of two different character matrices, which place D. provincialis as the most basal strepsirrhine when the new tarsal data are included. Interpreting our results in the context of other recent discoveries, we conclude that the lineage leading to the ancestral euprimate had already become somewhat leaping specialized, while certain specializations for the small branch niche came after crown primates began to radiate.
... Recent works dealing with European Eocene primates have focused on the description of new material (Hooker, 2007;Hooker, 2012;Hooker & Harrison, 2008;Marigó, Minwer-Barakat & Moyà-Solà, 2011;Gebo, Smith & Dagosto, 2012;Gebo et al., 2015;Minwer-Barakat et al., 2013;Femenias-Gual et al., 2015), the revision of previous taxonomic assignations Minwer-Barakat, Marigó & Moyà-Solà, 2016;Marigó et al., 2014) and the establishment of relationships between different taxa (Smith, Rose & Gingerich, 2006;Minwer-Barakat et al., 2017), with some exceptions focused on the diet (Ramdarshan, Merceron & Marivaux, 2012), the locomotor behaviour (Marigó et al., 2016) and the endocranial anatomy (Ramdarshan & Orliac, 2016) of several species. However, only a few contributions have been published regarding European primates from the early Eocene, recently including the revision of Agerinia roselli from Les Saleres and the description of the new species Agerinia smithorum from Casa Retjo-1 (Femenias-Gual et al., 2016a andFemenias-Gual et al., 2016b, respectively). ...
... Two phylogenetic analyses were run using a version of a character-taxon matrix of living and extinct primates as well as euarchontan outgroups that was originally published by Seiffert et al. (2005). This matrix has been successively modified (Seiffert et al., 2009) and a recent version was used by Marigó et al. (2016). The matrix analysed here (Data S1) includes 391 characters and 109 taxa for the first analysis, or 112 taxa for the second analysis (see 'Results of the Phylogenetic Analyses'). ...
... In this analysis, the clade formed by Agerinia, sivaladapids and asiadapines would not be nested within a monophyletic Adapiformes. These results have been obtained in previous analyses (see Marigó et al., 2016). ...
Background
The Eocene was the warmest epoch of the Cenozoic and recorded the appearance of several orders of modern mammals, including the first occurrence of Euprimates. During the Eocene, Euprimates were mainly represented by two groups, adapiforms and omomyiforms, which reached great abundance and diversity in the Northern Hemisphere. Despite this relative abundance, the record of early Eocene primates from the European continent is still scarce and poorly known, preventing the observation of clear morphological trends in the evolution of the group and the establishment of phylogenetic relationships among different lineages. However, knowledge about the early Eocene primates from the Iberian Peninsula has been recently increased through the description of new material of the genus Agerinia from several fossil sites from Northeastern Spain.
Methods
Here we present the first detailed study of the euprimate material from the locality of Masia de l’Hereuet (early Eocene, NE Spain). The described remains consist of one fragment of mandible and 15 isolated teeth. This work provides detailed descriptions, accurate measurements, high-resolution figures and thorough comparisons with other species of Agerinia as well with other Eurasian notharctids. Furthermore, the position of the different species of Agerinia has been tested with two phylogenetic analyses.
Results
The new material from Masia de l’Hereuet shows several traits that were previously unknown for the genus Agerinia, such as the morphology of the upper and lower fourth deciduous premolars and the P2, and the unfused mandible. Moreover, this material clearly differs from the other described species of Agerinia, A. roselli and A. smithorum, thus allowing the erection of the new species Agerinia marandati. The phylogenetic analyses place the three species of Agerinia in a single clade, in which A. smithorum is the most primitive species of this genus.
Discussion
The morphology of the upper molars reinforces the distinction of Agerinia from other notharctids like Periconodon. The analysis of the three described species of the genus, A. smithorum, A. marandati and A. roselli, reveals a progressive change in several morphological traits such as the number of roots and the position of the P1 and P2, the molarization of the P4, the reduction of the paraconid on the lower molars and the displacement of the mental foramina. These gradual modifications allow for the interpretation that these three species, described from the early Eocene of the Iberian Peninsula, are part of a single evolutionary lineage. The stratigraphical position of Masia de l’Hereuet and Casa Retjo-1 (type locality of A. smithorum) and the phylogenetic analyses developed in this work support this hypothesis.
... Adapiforms are among the first demonstrable crown primates in the fossil record (Rose et al. 1994), and are generally (but not universally) considered to be basal stem members of Strepsirrhini, the clade that contains the living lemurs, lorises, and galagos (Marivaux et al. 2013;Seiffert et al. 2015;Marigó et al. 2016;Ni et al. 2016). Members of the group first appeared in the early Eocene, and then underwent significant adaptive radiations on each of the northern continents (Godinot 1998(Godinot , 2015. ...
... Despite the fact that Aframonius and Afradapis are both thought to be folivores (Kirk & Simons 2001;Seiffert et al. 2010) and share very similar molar morphology and apomorphic features of the premolar dentition (notably extreme reduction of Afradapis-Caenopithecus clade (Kirk & Williams 2011;Marigó et al. 2011Marigó et al. , 2013; some analyses in Seiffert et al. 2009;Marigó et al. 2016; some analyses in Seiffert et al. 2010Seiffert et al. , 2015; (2) as part of a more inclusive clade uniting caenopithecines and adapines (some analyses in Seiffert et al. 2015;Marigó et al. 2016);or (3) or as a basal adapiform with no special relationship to caenopithecines or adapines (Ni et al. 2013. The latter hypothesis effectively implies that the derived morphological similarities of P 2 / 2 in Aframonius and loss of P 2 / 2 in Afradapis), phylogenetic analyses that have included both genera have nevertheless yielded remarkably different results. ...
... Despite the fact that Aframonius and Afradapis are both thought to be folivores (Kirk & Simons 2001;Seiffert et al. 2010) and share very similar molar morphology and apomorphic features of the premolar dentition (notably extreme reduction of Afradapis-Caenopithecus clade (Kirk & Williams 2011;Marigó et al. 2011Marigó et al. , 2013; some analyses in Seiffert et al. 2009;Marigó et al. 2016; some analyses in Seiffert et al. 2010Seiffert et al. , 2015; (2) as part of a more inclusive clade uniting caenopithecines and adapines (some analyses in Seiffert et al. 2015;Marigó et al. 2016);or (3) or as a basal adapiform with no special relationship to caenopithecines or adapines (Ni et al. 2013. The latter hypothesis effectively implies that the derived morphological similarities of P 2 / 2 in Aframonius and loss of P 2 / 2 in Afradapis), phylogenetic analyses that have included both genera have nevertheless yielded remarkably different results. ...
Caenopithecine adapiform primates are currently represented by two genera from the late Eocene of Egypt (Afradapis and Aframonius) and one from the middle Eocene of Switzerland (Caenopithecus). All are somewhat anthropoid-like in several aspects of their dental and gnathic morphology, and are inferred to have been highly folivorous. Here we describe a new caenopithecine genus and species, Masradapis tahai, from the ~37 million-year-old Locality BQ-2 in Egypt, that is represented by mandibular and maxillary fragments and isolated teeth. Masradapis is approximately the same size as Aframonius but differs in having a more dramatic distal increase in molar size, more complex upper molar shearing crests, and an exceptionally deep mandibular corpus. We also describe additional mandibles and part of the orbit and rostrum of Aframonius which suggest that it was probably diurnal. Phylogenetic analyses place Masradapis either as the sister taxon of Aframonius (parsimony), as a basal adapine (standard Bayesian), or as the sister taxon of Afradapis and Caenopithecus (Bayesian tip-dating). The latter analysis, when combined with Bayesian biogeographic analysis, suggests that a common ancestor of known caenopithecines dispersed to Afro-Arabia from Europe between 49.4 and 47.4 Ma, and that a trans-Tethyan back-dispersal explains Caenopithecus’ later presence in Europe.
For Masradapis: urn:lsid:zoobank.org:act:41BC8459-7CCE-487F-BC59-1C34257D5C4E
For Masradapis tahai: urn:lsid:zoobank.org:act:C0A620AD-6FCA-4649-A980-FCA237AFE39D
... The calcaneus is considered relatively a good indicator of positional patterns and paleoecological inferences because it is in direct contact with the preferred substrates of a primate. Calcaneal morphological complexes have been strongly related to specific behaviors, and they have been frequently used to infer positional behavior of fossil primates (Szalay and Decker, 1974;Ford, 1988;Strasser, 1988;Youlatos, 2003;Belmaker, 2010;Gilbert et al., 2010;Boyer et al., 2013;Gladman et al., 2013;Marig o et al., 2016). Many calcaneal features have been well described and functionally associated with different functional positional patterns. ...
... Furthermore, the high probability classification of the fossil calcaneus as Rhinopithecus appeared to provide some support to the suggested affinities between Mesopithecus and the odd-nosed colobines, and most particularly the snub-nosed monkeys (Jablonski, 2002;Pan et al., 2004). Moreover, our qualitative and quantitative analysis identified calcaneal characters, such as the length and form of the proximal calcaneoastragalar facet, the length of the proximal and distal calcaneal regions, and the form of the tuber calcanei, that are associated with specific functions of the foot that suggest differential habitat preferences (Szalay and Decker, 1974;Langdon, 1986;Ford, 1988;Strasser, 1988;Lewis, 1989;Gebo, 1993;Belmaker, 2010;Boyer et al., 2013;Gladman et al., 2013;Marig o et al., 2016). In general, the family Cercopithecidae is characterized by relatively long proximal calcaneal regions compared with other anthropoids (Strasser, 1988;Gebo, 1993). ...
Apart from a juvenile hominoid, the locality of Shuitangba (southwestern China, 6.5–6.0 Ma) has yielded a mandible and proximal femur attributed to the colobine genus Mesopithecus. A complete colobine calcaneus also accompanies this material, but its association with the other Mesopithecus material remains to be confirmed. These fossil elements are very important as they represent the oldest known colobines from East Asia,
extend the dispersal of Mesopithecus to southwestern China, and underscore its close affinities and potential ancestry to the odd-nosed colobines. The present article focuses on the functional morphology of this complete calcaneus to reconstruct the positional habits, infer the paleocology, and understand the dispersal patterns of this fossil colobine. The studied characters corroborate the attribution of this element to colobines and support potential affinities with the Mesopithecus remains of the same locality. Functionally, characters such as the long and narrow tuber calcanei, the short proximal calcaneal region, and the relatively extended and long and narrow proximal calcaneoastragalar facet appear to enable habitual pedal flexion with conjunct inversion
that accommodate the foot on diversely oriented and differently sized arboreal substrates. On the other hand, the relatively short distal calcaneal region is functionally related to (mainly terrestrial) quadrupedal activities, wherein thrust and rapid flexion are required. This combination of characters suggests that the Shuitangba colobine could move at ease on arboreal substrates and was also able to occasionally use terrestrial substrates. The potential affinities of this calcaneus to Mesopithecus and its positional profile most likely imply an eastward migration via forested corridors. In Shuitangba, this fossil colobine could trophically and positionally exploit a wide range of habitats successfully coexisting with resident hominoids.
... Qi and Beard (1998) made an early attempt to clarify relationships among sivaladapids, and more recently Ni et al. (2016) attempted to place a few sivaladapid taxa within the larger primate radiation. While our analysis does not examine as many characters as some more recent analyses on adapoids and early primates as a whole (e.g., Seiffert et al., 2005Seiffert et al., , 2009Seiffert et al., , 2015Rose et al., 2009;Marivaux et al., 2013;Marig o et al., 2016;Ni et al., 2016), it is notable in that it includes nearly all taxa that have been previously argued to be sivaladapids and also includes some of the most basal taxa of other adapoid groups for comparison. Thus, the phylogenetic analysis performed here represents the most comprehensive attempt to clarify relationships among known sivaladapid taxa to date. ...
... Future analyses may benefit from a much larger set of characters and taxa than examined here, so that sivaladapids can be considered within a broader context of adapoid and primate evolution. One suggestion might be to include all sivaladapid taxa into the most current matrix of Seiffert and colleagues (e.g., Seiffert et al., 2015;Marig o et al., 2016) or the recent analysis by Ni et al. (2016). ...
Over the past century, numerous vertebrate fossils collected near the town of Ramnagar, India, have proven to be important for understanding the evolution and biogeography of many mammalian groups. Primates from Ramnagar, though rare, include a number of hominoid specimens attributable to Sivapithecus, as well as a single published mandibular fragment preserving the P4-M1 of the Miocene adapoid Sivaladapis palaeindicus. Since 2010, we have renewed fossil prospecting in the Lower Siwalik deposits near Ramnagar in an attempt to better understand the evolution, biogeographic timing, and paleoclimatic context of mammalian radiations in Asia, with a particular focus on primates. Our explorations have resulted in the identification of new fossil localities, including the site of Sunetar. The age of Sunetar and the Ramnagar region, in general, is tentatively dated between 14 and 11 Ma. In 2014, a partial right mandible of a sivaladapid primate was recovered at Sunetar, preserving the corpus with P4 roots and worn M1-M3 dentition. Although sivaladapids are known by numerous specimens of two genera (Sivaladapis and Indraloris) at Lower Siwalik sites on the Potwar Plateau (Pakistan) and at the Middle Siwalik locality of Haritalyangar (India), this new specimen is just the second sivaladapid recovered from the Ramnagar region. Our analyses suggest that the new specimen is distinct from all other sivaladapids, and we therefore describe it as a new genus and species close to the base of the Sivaladapinae.
... Posteriorly, the medial trochlear rim is slightly damaged but it does not obscure the overall shape of the trochlear surface, which is slightly constricted and expands again plantarly. The articular surface of the trochlea continues to the plantar border of the astragalus, with no development of a posterior shelf like that seen in most strepsirrhines, adapoids, and some omomyids such as Necrolemur, Ourayia, and Chipetaia (Godinot and Dagosto, 1983;Gebo and Simons, 1987;Gebo et al., 2001;Dunn et al., 2006;Dunn, 2010;Marig o et al., 2016). The groove for the flexor hallucis longus tendon on the posterior aspect of the trochlea is wide and shallow and aligned with the posterior aspect of the trochlea, in contrast to the condition in asiadapids, in which this groove is narrower, deeper, lateral to the posterior trochlea, and demarcated from the trochlea dorsomedially by an oblique ridge (Fig. 7). ...
... Clearly, there is much room for interpretation in the reconstruction of locomotor behavior in fossil taxa for which there are no close living relatives or close analogues. Comparison of the calcaneus of Marcgodinotius with the distinctly elongated calcaneus of the cercamoniid Anchomomys frontanyensis, the only adapoid of similar body size for which postcranial material is known, strongly suggests that Marcgodinotius was not a specialized leaper (Marig o et al., 2016). While it is possible that asiadapids were slow climbers, their morphology does not overwhelmingly indicate adaptation to this lifestyle, instead suggesting generalized arboreal locomotion. ...
... Phylogenetic and functional studies of primate and euarchontan tarsal evolution suggest that moderate leaping adaptations were present in the earliest crown primates (Boyer et al 2013, Marigó et al., 2016Boyer et al., 2017; but see Dunn et al., 2016). The tarsal anatomy of the dentally primitive Donrusellia provincialis as well as reconstructions of adaptive shifts in the functional morphology of the hand and foot across Euarchonta have been used to suggest that leaping adaptations may have even preceded morphological commitment to the fine branch niche in early primates (Boyer & Seiffert, 2013;Boyer et al., 2013b;2016;Yapuncich et al., 2017). ...
Multiple competing hypotheses attribute the evolution of the suite of traits that distinguish primates from their closest relatives, including forward-facing eyes which create a wide field of binocular vision, to specific behavioral and ecological factors. The Grasp-Leaping Hypothesis suggests that the evolution of these traits in basal primates was driven by the demands of a form of leaping locomotion unique to primates. Whether the Grasp-Leaping Hypothesis provides a viable mechanism for the evolution of primates’ forward-facing eyes remains untested. To determine whether grasp-leaping locomotion may have contributed to driving the evolution of primates’ forward-facing eyes, the importance of vision within the binocular field for this type of leaping was evaluated experimentally in Cheirogaleus medius, one of the cheirogaleid primate species considered reasonable living analogues of the earliest primates. Availability of binocular visual cues was experimentally restricted using a head-mounted blinder that narrowed binocular visual field without altering the total visual field. Animals altered their launch behavior, reduced their horizontal leap speed, and were significantly more likely to select paths that offered the shortest available leaps when their binocular field was restricted. Restriction of binocular cue availability also significantly increased the probability of adverse landings even when statistically controlling for potentially confounding variables such as leap distance, horizontal leap speed, learning effects, etc. These results suggest a functional mechanism by which selection for improved grasp-leaping could also have contributed to the evolution of forward-facing eyes in the earliest crown primates.
... found no relationship between fibular facet angle and leaping frequency. However, within lemuriforms and platyrrhines there is a significant correlation between body mass Marigo et al. (2016) and facet angle . Among hominoids, the fibular facet is flared more laterally in African apes compared with humans, receiving the fibular malleolus during dorsiflexion. ...
The primate hindfoot consists of only two bones—the talus (ankle) and the calcaneus (heel bone). Yet, the hindfoot is a keystone of the foot that serves as a lever for multiple muscles. While many bony features of the hindfoot have been found to significantly covary with locomotor behavior, they also show a significant phylogenetic signal, indicating that closely related species tend to show similar traits due to common ancestry. As such, the hindfoot has been one of the most informative and diagnostic features for understanding foot function and inferring behavior in both extant and extinct primates.In this chapter, we discuss the anatomy of the hindfoot
from a proximal to distal direction, beginning with the distal tibia and fibula, passing through the talus
, and finally to the calcaneus
. We highlight the fact that, compared with other mammals, primates are characterized by elongation of the tarsal elements, including the neck of the talus
and distal calcaneus
. These traits are believed to relate to pedal grasping
and powerful leaping, locomotor behaviors which may have been important for the earliest euprimates. We compare the whole-bone morphology, projections and articular facets, and internal trabecular microstructure of each hindfoot
bone across primate species and locomotor mode.KeywordsTalusCalcaneusNavicularExternal anatomyFunctional anatomyJointsHindfootSubtalar jointCalcaneocuboid jointTalocrural jointTalonavicular jointHeelAchilles tendon
... , Marigó et al. (2016) quantified inter-subject variability in the morphology of the calcanei and astragali of a middle Eocene primate, Anchomomys frontanyensis, to assess its phylogenetic position compared to other crown strepsirrhines. They demonstrate a large statistical overlap in linear metrics of morphology within crown strepsirrhines, both living and fossil; however, this was not explained further. ...
The fossil record is scarce and incomplete by nature. Animals and ecological processes devour soft tissue and important bony details over time and, when the dust settles, we are faced with a patchy record full of variation. Fossil taxa are usually defined by craniodental characteristics, so unless postcranial bones are found associated with a skull, assignment to taxon is unstable. Naming a locomotor category based on fossil bone morphology by analogy to living hominoids is not uncommon, and when no single locomotor label fits, postcrania are often described as exhibiting a “mosaic” of traits. Here, we contend that the unavoidable variation that characterises the fossil record can be described far more rigorously based on extensive work in human neurobiology and neuroanatomy, movement sciences and motor control and biomechanics research. In neurobiology, degeneracy is a natural mechanism of adaptation allowing system elements that are structurally different to perform the same function. This concept differs from redundancy as understood in engineering, where the same function is performed by identical elements. Assuming degeneracy, structurally different elements are able to produce different outputs in a range of environmental contexts, favouring ecological robusticity by enabling adaptations. Furthermore, as degeneracy extends to genome level, genetic variation is sustained, so that genes which might benefit an organism in a different environment remain part of the genome, favouring species’ evolvability.
... The assignment of the calcaneus from LLU-1 to A. smithorum is mainly done by size comparison with the calcaneus of A. smithorum from CR-1 (Femenias-Gual et al., 2017a), which is roughly the same size. Cuboid facet area correlates very well with m2 length across primates (see Marigó et al., 2016), and it was used to assign the primate calcaneus from CR-1 to A. smithorum (Femenias-Gual et al., 2017a). Thus, even though the calcaneus from LLU-1 does not preserve the cuboid facet and no m2 has been recovered from this site, we can confidently attribute it to Agerinia because no other primates have been found so far in that location, and because this primate's calcaneus and teeth are roughly the same size as those from CR-1. ...
During the last decade, field work carried out in the lower Eocene deposits of the Àger Basin (southern Pyrenean basins, northeast Spain) has allowed the publication of new early primate material, including the first identification of plesiadapiform remains in Spain (Arcius ilerdensis from Masia de l’Hereuet) and the description of two new species of adapiforms: Agerinia smithorum from Casa Retjo-1 and Agerinia marandati from Masia de l’Hereuet. However, the fossil material recovered is still scarce and fragmentary. For this reason, during the last few years prospecting has been carried out in order to find new localities with primate remains. This paper describes the results of these campaigns, reporting four new lower Eocene primate localities, in which some previously unknown elements have been recovered. More specifically, the locality of Cabana del Llúcio-1 has yielded the first I1, I2, and P1 for the genus Agerinia and the first M1 of the species A. smithorum. Moreover, a fragment of calcaneus from this site provides further information about the morphology of this bone in A. smithorum. The material from Cabana del Llúcio-1 displays some intermediate traits between A. smithorum from Casa Retjo-1 and A. marandati from Masia de l’Hereuet. These transitional features are consistent with the stratigraphic position of Cabana del Llúcio and support the previously proposed anagenetic lineage Agerinia smithorum–A. marandati–A. roselli.
... Postcranial elements, such as long bones and tarsus, are very informative for both phylogenetic and functional interpretation. In primates, the ankle has been intensely studied and is very reflective of their pedal functions and associated substrate use, as well as of their leaping specialization (Boyer et al., 2013aBoyer & Seiffert, 2013;Chester et al., 2015;Gebo, 1985;Gebo & Dagosto, 1988;Marigó et al., 2016;Seiffert et al., 2015;Yapuncich et al., 2017). ...
Primate origins are subject to important controversies. The initial radiation of first Primates and their precise relationships within Euarchontans (the clade including Primates, Scandentians, Dermopterans, and Plesiadapiformes) are still debated. Moreover, the functional and evolutionary interpretation of some of the morphological characters that define Primates is still uncertain. Among them are the acquisition of manual and pedal prehensile abilities, with a specialized grasping foot bearing an opposable hallux, and nails instead of claws on the distal phalanges. Thus, the ancestral morphotype of Primates is under active investigation, despite the consensus on the arboreality and small size of our early ancestors. This PhD dissertation aimed at revisiting some blurry aspects of primate origins focusing on hand and foot grasping mechanisms, through an interdisciplinary approach blending ethology, biomechanics, comparative morphology and phylogenetics. A reappraisal of the genus Plesiadapis (Plesiadapiformes) led to question a recent hypothesis on early Primates’ phylogeny. In addition, a quantitative analysis of manual and pedal postures relatively to substrate type used during locomotion, followed by a morphological study of hand and foot metapodials and phalanges were also conducted on series of primate and non-primate species. The results were analyzed in an integrative way to relate morphological features to functional attributes, along with assessing their phylogenetic importance. Among many results, this work allowed proposing alternative hypotheses regarding two key characters of primates, the primary function of nails: more linked to sensitivity than to a mechanical advantage; and the environmental scenario that may have driven the evolution of hallucal grasping capabilities: small vertical substrates instead of the fine branch niche. Moreover, in an effort to better understand biomechanical constraints at play during arboreal locomotion, a novel spatially-resolved force sensor was created, which has potential applications in various fields such as robotics.
... The great diversity present in the Adapis group poses a problem for the performance of phylogenetic analyses of primates contain- ing Adapis parisiensis from now on, since what has been tradi- tionally called A. parisiensis is most probably composed of different species. Common character matrices used for phylogenetic ana- lyses ( Seiffert et al., 2005Seiffert et al., , 2009Marig o et al., 2011Marig o et al., , 2013Marig o et al., , 2016Femenias-Gual et al., 2017a, 2017b) contain codifications of hu- meral features such as the brachioradialis flange (usually coded as moderate to large for A. parisiensis), the trochlearecapitular junc- tion (usually coded as confluent), and the relative width of the capitulum, which may need to be re-coded in future analyses in order to include all the character states present in the Adapis group sample. Indeed, exchanging "Adapis parisiensis" for "Adapis group" would be better in future phylogenetic analyses using postcranial characters in order to illustrate that A. parisiensis is most probably a compilation of different closely related species or even closely related genera. ...
Twenty humeral specimens from the old and new Quercy collections attributed to the fossil primates Adapis and Palaeolemur are described and analysed together. We provide a qualitative and quantitative analysis of the different humeri, revealing that high variability is present within the “Adapis group” sample. Six different morphotypes are identified, confirming that what has often been called “Adapis parisiensis” is a mix of different species that present different locomotor adaptations. Such a relatively high level of locomotor diversity is unique in the Paleogene primate fossil record. The humeral proportions of Adapis overlap with different groups of extant strepsirrhines and platyrrhines depending on the specimen, so the popular view of Adapis as a loris-like slow climbing primate does not apply to the whole sample presented here. Moreover, different humeral features traditionally associated with “Adapis parisiensis” such as the absence of a zona conoidea and a reduced brachioradialis flange, are variable depending on the sample studied. In addition, results of our analyses show that adapine and omomyid humeral morphology overlap extensively, leading us to question the accuracy of taxonomic attributions based on morphology of isolated humeri at localities where omomyids and adapines of similar size coexist. Finally, assuming our different morphotypes represent different species within two genera, we propose a phylogenetic hypothesis relating these morphotypes, which inhabited a small geographic area.
... In the current study, we further showed that (a) feathertail gliders display a flexible positional behavior, composed of quadrupedalism, climbing, clambering and gliding/leaping, (b) they frequently use and prefer small moderately inclined substrates handled by a hallucal grasp, (c) climbing and clinging are related to large vertical substrates using an abducted grasp, and (d) gliding (leaping) bouts initiate from small vertical substrates and terminate on small oblique ones. This profile is similar to those reconstructed for some of the earliest euprimates, such as D. provincialis, T. belgica, Teilhardina brandti, Ar. achilles, Asiadapis cambayensis, Marcgodinotius indicus, Vastanomys major, and Anchomomys frontayensis (Rose et al., 2009(Rose et al., , 2011Ni et al., 2013;Gebo et al., 2015;Dunn et al., 2016;Marig o et al., 2016;Boyer et al., 2017). As feathertail gliders fall at the lower end of the body mass range of the earliest representatives of euprimates, this indicates that this suite of adaptations can be present in very small arboreal mammals, a fact not excluding a very small-sized origin of primates (Gebo, 2004). ...
Debates on early euprimate evolution are related to the understanding of the ecological context that promoted their unique adaptations. Currently, these discussions mainly revolve around the habitual use of the small-branch niche or the frequent utilization of wider, and probably, strongly inclined substrates by euprimate ancestors. The current fossil evidence implies a diversity of arboreal quadrupedal behaviors for these early euprimates, associated with the use of various types of substrates. However, inferring the positional behavior of early euprimates based exclusively on fossils fails to unravel the positional flexibility in terms of modes and substrate use, which is important for understanding key adaptations related to limb postures. Following previous research, we studied the positional behavior, substrate use and pedal grasping modes of the marsupial feathertail gliders to investigate patterns of arboreal behavior that may be analogous to those exhibited by early euprimate ancestors. For the purposes of the current study, we observed and filmed 15 male and 20 female captive adult feathertail gliders Acrobates pygmaeus (Marsupialia: Diprotodontia: Acrobatidae) in a large enclosure in the Nocturnal Pavilion of Nowe Zoo, Poznań, Poland. Our observations demonstrated a strong preference for small and for horizontal substrates, avoidance of large and of vertical ones, a diverse positional repertoire mainly composed of quadrupedalism, clambering, climbing and gliding, the last occurring from small and oblique and vertical substrates, and the dominant use of hallucal grasping, especially on small, horizontal and oblique substrates. We thus consider that the generalized profile of A. pygmaeus could fit in a stage where the euarchontan heritage of vertical clawed activities on large substrates has decreased in favor of the use of small moderately inclined substrates efficiently negotiated by diagonal sequence quadrupedalism and handled via an apparently powerful hallucal grasp. Competent use of small substrates could have further expanded into small vertical substrates, which would progressively serve as new climbing platforms and takeoff perches for unspecialized leaping. We feel that this stage may have occurred early in euprimate evolution, as small body size likely provided the necessary behavioral flexibility to exploit various niches. Depending on alternative scenarios, it could represent that of the common ancestor of euprimates or be rooted at the base of strepsirrhine evolution. This study underscores the important of analyzing the behavior of extant models to infer the locomotor evolution of euarchontans, primates or euprimates.
... (Godinot, 2015), and, even though it is still included in Cercamoniinae following traditional systematic studies, its phylogenetic position remains controversial. Recent studies have presented results of phylogenetic analyses that recover anchomomyins outside of a monophyletic Adapiformes, and more closely related to azibiids, djebelemurines and extant strepsirrhines (Marig o et al., 2011(Marig o et al., , 2013(Marig o et al., , 2016Femenias-Gual et al., 2017). ...
Primates reached a great abundance and diversity during the Eocene, favored by warm temperatures and by the development of dense forests throughout the Northern Hemisphere. Here we describe new primate material from La Verrerie de Roches, a Middle Eocene karstic infill situated in the Jura Region (Switzerland), consisting of more than 80 dental remains. The primate assemblage from La Verrerie de Roches includes five different taxa. The best represented primate is Necrolemur aff. anadoni, similar in size and overall morphology to Necrolemur anadoni but resembling in some features the younger species Necrolemur antiquus. Microchoerines are also represented by two species of Pseudoloris, P. pyrenaicus and Pseudoloris parvulus, constituting the unique joint record of these two species known up to now. Remains of Adapiformes are limited to one isolated tooth of a large anchomomyin and another tooth belonging to the small adapine Microadapis cf. sciureus. The studied primate association allows assigning La Verrerie de Roches to the Robiacian Land Mammal Age. More specifically, this site can be confidently situated between the MP15 and MP16 reference levels, although the primate assemblage probably indicates some degree of temporal mixing. This is the first record of P. pyrenaicus and a form closely related to N. anadoni out of the Iberian Peninsula. The identification of these microchoerines in Switzerland gives further support to the connection of NE Spain and Central Europe during the Middle Eocene.
... The analysis of several concentrates held at Institut Català de Paleontologia Miquel Crusafont (ICP) revealed the presence of numerous Eocene lizard remains (Bolet and Evans, 2010a), and new material has been recovered in the last years after additional fieldwork. Many of the Eocene localities with samples in the collection are important in yielding fossil primates that have been object of several studies (e.g., Marigó et al., 2013Marigó et al., , 2016Minwer-Barakat et al., 2012, 2013Femenias-Gual et al., 2016a, 2016b. The present paper concerns those localities of an early Eocene age that have yielded interesting lizard material. ...
Lizard and amphisbaenian fossil material is described for the first time from early Eocene localities in Spain, more specifically from Catalonia (north-eastern Iberian Peninsula). Material is fragmentary and scarce, but diagnostic enough to provide a first approach to the composition of lizard assemblages. The following taxa are recorded: Geiseltaliellus and a second indeterminate pleurodont iguanid; an agamid similar to " Tinosaurus " ; an indeterminate gekkotan; a scincoid, possibly scincid lizard; a lacertid similar to Dormaalisaurus; an indeterminate amphisbaenian; a glyptosaurin glyptosau-rine (cf. Placosaurus); an indeterminate anguine; and, finally, an indeterminate " necro-saur. " The studied localities range from the MP8+9 to the MP10, and thus complement the only previously known lizard locality of the Iberian early Eocene, the Portuguese locality of Silveirinha, which corresponds to the MP7. An analysis of the composition of these new assemblages suggests a great amount of homogeneity through the different levels of the early Eocene, and also between Iberian and contemporaneous assemblages from the rest of Europe. The lack of an Iberian Paleocene record for lizards strengthens the importance of the study of early Eocene assemblages because these are the only ones available for comparison with Cretaceous associations, providing critical information on the changes in composition between Mesozoic and early Ceno-zoic lizard faunas related to the K/Pg extinction event.
... We suggest that authors create a metadata table for listing these five elements above on each scan. This table can then be provided in the text listing materials examined (e.g., Seiffert et al., 2015;Marigó et al., 2016;Fulwood et al., in press) or as an appendix or supplementary file (e.g., Copes et al., 2016;Boyer et al., 2016). ...
Advancement of understanding in paleontology and biology has always been hindered by difficulty in accessing comparative data. With current and burgeoning technology, the severity of this hindrance can be substantially reduced. Researchers and museum personnel generating three-dimensional (3-D) digital models of museum specimens can archive them using internet repositories that can then be explored and utilized by other researchers and private individuals without a museum trip. We focus on MorphoSource, the largest web archive for 3-D museum data at present. We describe the site, how to use it most effectively in its current form, and best practices for file formats and metadata inclusion to aid the growing community wishing to utilize it for distributing 3-D digital data. The potential rewards of successfully crowd sourcing the digitization of museum collections from the research community are great, as it should ensure rapid availability of the most important datasets. Challenges include long-term governance (i.e., maintaining site functionality, supporting large amounts of digital storage, and monitoring/updating file to prevent bit rot, which is the slow and random corruption of electronic data over time, and data format obsolescence, which is the problem of data becoming unreadable or ineffective because of the loss of functional software necessary for access), and utilization by the community (i.e., detecting and minimizing user error in creating data records, incentivizing data sharing by researchers and institutions alike, and protecting stakeholder rights to data, while maximizing accessibility and discoverability).
MorphoSource serves as a proof-of-concept of how these kinds of challenges can be met. Accordingly, it is generally recognized as the most appropriate repository for large, raw datasets of fossil organisms and/or comparative samples. Its existence has begun to transform data transparency standards because journal reviewers, editors, and grant officers now often suggest or require that 3-D data be made available through this site.
... 1924), as well as to infer positional behaviors in fossil taxa (Boyer and Seiffert, 2013;Boyer, Seiffert, & Simons, 2010;Boyer, Yapuncich, Butler, Dunn, & Seiffert, 2015;Dagosto, 1983;Dunn et al., 2016;Gebo and Simons, 1987;Gebo, 1988;Gebo, Dagosto, Beard, & Ni, 2008;Gebo, Dagosto, Beard, Qi, & Wang, 2000;Gebo, Dagosto, & Rose, 1991;Gebo, Smith, & Dagosto, 2012;Marig o, Roig, Seiffert, Moy a-Sol a, Marivaux et al., 2010;Marivaux et al., 2011;Seiffert and Simons, 2001;Seiffert, Costeur, & Boyer, 2015;). ...
Objective:
On the talus, the position and depth of the groove for the flexor hallucis longus tendon have been used to infer phylogenetic affinities and positional behaviors of fossil primates. This study quantifies aspects of the flexor hallucis longus groove (FHLG) to test if: (1) a lateral FHLG is a derived strepsirrhine feature, (2) a lateral FHLG reflects inverted and abducted foot postures, and (3) a deeper FHLG indicates a larger muscle.
Methods:
We used linear measurements of microCT-generated models from a sample of euarchontans (n?=?378 specimens, 125 species) to quantify FHLG position and depth. Data are analyzed with ANOVA, Ordinary and Phylogenetic Generalized Least Squares, and Bayesian Ancestral State Reconstruction (ASR).
Results:
Extant strepsirrhines, adapiforms, plesiadapiforms, dermopterans, and Ptilocercus exhibit lateral FHLGs. Extant anthropoids, subfossil lemurs, and Tupaia have medial FHLGs. FHLGs of omomyiforms and basal fossil anthropoids are intermediate between those of strepsirrhines and extant anthropoids. FHLG position has few correlations with pedal inversion features. Relative FHLG depth is not significantly correlated with body mass. ASRs support a directional model for FHLG position and a random walk model for FHLG depth.
Conclusions:
The prevalence of lateral FHLGs in many non-euprimates suggests a lateral FHLG is not a derived strepsirrhine feature. The lack of correlations with pedal inversion features suggests a lateral FHLG is not a sufficient indicator of strepsirrhine-like foot postures. Instead, a lateral FHLG may reduce the risk of tendon displacement in abducted foot postures on large diameter supports. A deep FHLG does not indicate a larger muscle, but likely reduces bowstringing during plantarflexion.
... Ancestral state reconstructions discussed above indicate that the strepsirrhine condition of having a relatively large stapedial canal is primitive and therefore not phylogenetically informative with respect to relationships within Euprimates. Furthermore, the condition in Mahgarita appears to be convergently haplorhine-like, given currently supported phylogenies which nest it deeply within adapiforms (Kirk and Williams, 2011;Marig o et al., 2016;this study). ...
Primate species typically differ from other mammals in having bony canals that enclose the branches of the internal carotid artery (ICA) as they pass through the middle ear. The presence and relative size of these canals varies among major primate clades. As a result, differences in the anatomy of the canals for the promontorial and stapedial branches of the ICA have been cited as evidence of either haplorhine or strepsirrhine affinities among otherwise enigmatic early fossil euprimates. Here we use micro X-ray computed tomography to compile the largest quantitative dataset on ICA canal sizes. The data suggest greater variation of the ICA canals within some groups than has been previously appreciated. For example, Lepilemur and Avahi differ from most other lemuriforms in having a larger promontorial canal than stapedial canal. Furthermore, various lemurids are intraspecifically variable in relative canal size, with the promontorial canal being larger than the stapedial canal in some individuals but not others. In species where the promontorial artery supplies the brain with blood, the size of the promontorial canal is significantly correlated with endocranial volume (ECV). Among species with alternate routes of encephalic blood supply, the promontorial canal is highly reduced relative to ECV, and correlated with both ECV and cranium size. Ancestral state reconstructions incorporating data from fossils suggest that the last common ancestor of living primates had promontorial and stapedial canals that were similar to each other in size and large relative to ECV. We conclude that the plesiomorphic condition for crown primates is to have a patent promontorial artery supplying the brain and a patent stapedial artery for various non-encephalic structures. This inferred ancestral condition is exhibited by treeshrews and most early fossil euprimates, while extant primates exhibit reduction in one canal or another. The only early fossils deviating from this plesiomorphic condition are Adapis parisiensis with a reduced promontorial canal, and Rooneyia and Mahgarita with reduced stapedial canals.
... In the Iberian Peninsula, the first studies of Eocene primates were undertaken in the 1960s (Crusafont-Pairó, 1967). In the last decade, the research team of the Institut Català de Paleontologia Miquel Crusafont (ICP) has restarted the study of the Paleogene primate record from Spain, but focusing on middle and late Eocene sites , 2012, 2013a, 2013b, 2015a, 2015b, including the definition of several new anchomomyins (Marigó et al., , 2011(Marigó et al., , 2013 and the first interpretations about their locomotion (Marigó et al., 2016). On the contrary, recent studies of early Eocene primates from the Iberian Peninsula only involve some preliminary studies of Euprimates (Femenias-Gual et al., 2014, 2015 and the description of Arcius from Masia de l'Hereuet, the first record of Plesiadapiformes from Spain . ...
In this work, new dental material of Agerinia roselli from its type locality, Les Saleres (NE Spain), is described. An emended diagnosis of the species is provided, together with a redescription of the entire hypodigm from that locality, which was necessary due to some inaccuracies in previous descriptions. The studied material includes 12 teeth (from p3 to m3); the roots of the anterior premolars preserved in a mandible fragment are reported for the first time. Some previously undescribed traits have been identified after the new analysis of this material, such as the p4 with distinct hypoconid and entoconid and the tiny paraconid on the m1. A detailed comparison with other cercamoniines has been made. The body mass of A. roselli, ranging from 650 to 900 g, has also been estimated. The presence of a minuscule paraconid in the m1 is the most reliable criterion for distinguishing this molar from the m2. This is supported by the complete absence of paraconid in four m2 preserved in mandible fragments. The trigonid length seems to be less reliable for distinguishing m1 from m2 , due to its high variability in this species. Concluding, this study updates the knowledge about the dental anatomy of A. roselli and demonstrates that it is a valid taxon clearly distinguishable from other cercamoniines.
... In the Iberian Peninsula, the study of Eocene mammals has received increasing attention in recent decades, mainly due to the presence of continuous and well-exposed continental series of this epoch, containing abundant vertebrate remains. However, recent work has been focused on a few mammal orders (especially primates; see Marig o et al., 2010Marig o et al., , 2012Marig o et al., , 2013Marig o et al., , 2014Marig o et al., , 2016, though new data on groups such as rodents have been scarce in recent years. ...
The locality of Sant Jaume de Frontanyà (Eastern Pyrenees, Catalonia, northeastern Spain) includes four fossil-bearing levels with an extraordinary abundance of mammal remains, representing the most significant middle Eocene site from the Iberian Peninsula. Despite this, the fauna from this locality has not been studied in detail. Recent work has mostly focused on the primates from the oldest levels, including the description of two new species, Anchomomys frontanyensis and Pseudoloris pyrenaicus. Recently, study of the primate remains from the uppermost level, Sant Jaume de Frontanyà-1 (SJF-1), has led to the description of a new species of Necrolemur. On the other hand, other mammal groups such as rodents are practically undescribed. In this work, rodent remains from SJF-1 are described for the first time. Three different forms have been identified: one glirid, referred to Glamys aff. robiacensis, and two theridomyids that have allowed the erection of the new species Paradelomys santjaumensis and Elfomys catalaunicus, suggested to be the most primitive members of the genera Paradelomys and Elfomys. These three forms show more primitive traits than other species from upper Bartonian (MP16) localities such as Robiac, Grisolles, and Le Bretou. Locality SJF-1 is therefore assigned to the lower Bartonian (MP15), with an age slightly older than Chéry-Chartreuve, and represents the first occurrence of the genera Paradelomys and Elfomys. Moreover, this dating allows us to place the only record of Necrolemur from the Iberian Peninsula in a correct chronological framework, shedding new light on the evolution of this primate genus. http://zoobank.org/urn:lsid:zoobank.org:pub:3609A71E-9414-4935-BD58-BE7812C49497 Citation for this article: Bonilla-Salomón, I., R. Minwer-Barakat, M. Vianey-Liaud, and S. Moyà-Solà. 2016. Middle Eocene rodents from Sant Jaume de Frontanyà (eastern Pyrenees, northern Spain) and biochronological implications. Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2016.1121
The genus Homo, as currently known, includes several hominin taxa that span a time period from roughly 2.8 million years ago (Ma) to the present. Nearly all of these taxa possess feet that appear, at least superficially, anatomically similar to the feet of modern humans. They possess clear adaptations for terrestrial bipedalism, and the range of morphological diversity is relatively constrained compared with that observed among earlier hominins. However, there does exist variation in foot anatomy among Homo taxa, which leads to questions regarding whether and how patterns of foot function and locomotion may have varied across fossil Homo. Here, we explore these anatomical variations, introduce some of the preliminary hypotheses regarding how foot function among Homo taxa may have varied, and highlight key areas where our current knowledge is limited and where focused studies may prove fruitful.Keywords
Homo
NeanderthalsDmanisiIleretKoobi ForaGran DolinaSima de los HuesosDinalediFlores
We describe the first known navicular bones for an Eocene euprimate from Europe and assess their implications for early patterns of locomotor evolution in primates. Recovered from the fossil site of Sant Jaume de Frontanyà-3C (Barcelona, Spain), the naviculars are attributed to Anchomomys frontanyensis. The small size of A. frontanyensis allows us to consider behavioral implications of comparisons with omomyiforms, regardless of allometric sources of navicular variation. Researchers usually consider omomyiforms to be more prone to leaping than contemporaneous adapiforms partly because of the more pronounced elongation of omomyiform tarsal elements. However, A. frontanyensis differs from other adapiforms and is similar to some omomyiforms in its more elongated navicular proportions. Although this might raise questions about attribution of these naviculars to A. frontanyensis, the elements exhibit clear strepsirrhine affinities leaving little doubt about the attribution: the bones' mesocuneiform facets contact their cuboid facets. We further propose that this strepsirrhine-specific feature in A. frontanyensis and other adapiforms reflects use of more inverted foot postures and potentially smaller substrates than sympatric omomyiforms that lack it. Thus substrate differences may have influenced niche partitioning in Eocene euprimate communities along with differences in locomotor agility. As previous studies on the astragalus and the calcaneus have suggested, this study on the navicular is consistent with the hypothesis that the locomotor mode of A. frontanyensis was similar to that of extant cheirogaleids, especially species of Microcebus and Mirza.
The new species Agerinia smithorum (Adapiformes, Primates) from the early Eocene of the Iberian Peninsula is erected in this work. An emended diagnosis of the genus is provided, together with a broad description of the new species and comparisons with other samples assigned to Agerinia and other similar medium-sized cercamoniines. The new species is based on the most complete specimen of this genus published to date, a mandible preserving the alveoli of the canine and P1 , the roots of the P2 and all teeth from P3 to M3 . It was found in Casa Retjo-1, a new early Eocene locality from Northeastern Spain. The studied specimen is clearly distinguishable from other cercamoniines such as Periconodon, Darwinius, and Donrussellia, but very similar to Agerinia roselli, especially in the similar height of P3 and P4 and the general morphology of the molars, therefore allowing the allocation to the same genus. However, it is undoubtedly distinct from A. roselli, having a less molarized P4 and showing a larger paraconid in the M1 and a tiny one in the M2 , among other differences. The body mass of A. smithorum has also been estimated, ranging from 652 to 724 g, similar to that of A. roselli. The primitive traits shown by A. smithorum (moderately molarized P4 , large paraconid in the M1 and small but distinct in the M2 ) suggest that it could be the ancestor of A. roselli.
Objectives:
The presence of Microchoerus in Sant Cugat de Gavadons (Late Eocene, Ebro Basin, Northeastern Spain) was first noted by M. Crusafont, who described a fragment of maxilla with two teeth that he interpreted as P(4) and M(1) and referred this specimen to the species Microchoerus ornatus. The objective of this work is to study in detail this fossil and check if the previous taxonomic determination was correct.
Methods:
We reexamine the single specimen from Sant Cugat de Gavadons, providing for the first time detailed descriptions, measurements and illustrations. We also compare this fossil with the holotype of Microchoerus ornatus from Mormont Entreroches (Switzerland) and with the type material of all other described species of Microchoerus.
Results:
Although the scarcity of material from Sant Cugat de Gavadons and the strong wear of the two available teeth (which in fact correspond to P(3) and P(4) ) do not allow a determination at the specific level, it is clear that this form presents notable differences with the type of M. ornatus and must not be referred to this species.
Discussion:
Neither the anatomical identification of the two teeth of this maxillary fragment, nor the specific determination of the specimen from Sant Cugat de Gavadons was correct. The ascription of this fossil to Microchoerus ornatus, which represented the only mention of the species in the Iberian Peninsula, is no longer valid. Therefore, the known geographical range of M. ornatus remains restricted to Switzerland. Am J Phys Anthropol, 2016. © 2016 Wiley Periodicals, Inc.
Objectives
The material of Necrolemur (Microchoerinae, Omomyidae, Primates) from the Middle Eocene (Robiacian) locality of Sant Jaume de Frontanyà (Eastern Pyrenees) is described. This is the first confirmable record of this genus from Spain.MethodsA mandible fragment bearing P4-M3 and 15 isolated teeth have been carefully described and compared with all the known species of Necrolemur (namely Necrolemur antiquus, Necrolemur zitteli and Necrolemur cf. zitteli from Egerkingen α) and with Nannopithex filholi.ResultsThe studied material shows substantial differences from all previously described forms of Necrolemur and can be erected as a new species. Necrolemur anadoni sp. nov. is characterized by its small size, weak enamel wrinkling, lower molars with the trigonid significantly narrower than the talonid, distinct paraconid in the M1 but poorly differentiated M2 and M3 paraconids, relatively short M3 hypoconulid lobe, M1-2 with tubercular buccal metaconule, crest-shaped lingual metaconule, hypocone connected to the protocone by a weak postprotocingulum, and M3 with a very reduced talon basin. It exhibits intermediate size and morphological features between the older Nannopithex filholi and the more recent Necrolemur antiquus.Conclusions
This finding allows reinterpretation of the phylogenetic relationships of the known species of Necrolemur. Necrolemur anadoni is considered a direct descendant of Nannopithex filholi and the ancestor of Necrolemur antiquus, whereas Necrolemur zitteli would be a descendant of N. antiquus. Finally, Necrolemur cf. zitteli from Egerkingen most likely evolved independently from N. filholi, being thus separated from the N. filholi-N. anadoni-N. antiquus lineage. Am J Phys Anthropol, 2015. © 2015 Wiley Periodicals, Inc.
The middle Eocene species Caenopithecus lemuroides, known solely from the Egerkingen fissure fillings in Switzerland, was the first Paleogene fossil primate to be correctly identified as such (by Ludwig Rütimeyer in 1862), but has long been represented only by fragmentary mandibular and maxillary remains. More recent discoveries of adapiform fossils in other parts of the world have revealed Caenopithecus to be a biogeographic enigma, as it is potentially more closely related to Eocene adapiforms from Africa, Asia, and North America than it is to any known European forms. More anatomical evidence is needed, however, to provide robust tests of such phylogenetic hypotheses. Here we describe and analyze the first postcranial remains that can be attributed to C. lemuroides—an astragalus and three calcanei held in the collections of the Naturhistorisches Museum Basel that were likely recovered from Egerkingen over a century ago. Qualitative and multivariate morphometric analyses of these elements suggest that C. lemuroides was even more loris-like than European adapines such as Adapis and Leptadapis, and was not simply an adapine with an aberrant dentition. The astragalus of Caenopithecus is similar to that of younger Afradapis from the late Eocene of Egypt, and parsimony and Bayesian phylogenetic analyses that include the new tarsal data strongly support the placement of Afradapis and Caenopithecus as sister taxa to the exclusion of all other known adapiforms, thus implying that dispersal between Europe and Africa occurred during the middle Eocene. The new tarsal evidence, combined with previously known craniodental fossils, allows us to reconstruct C. lemuroides as having been an arboreal and highly folivorous 1.5–2.5 kg primate that likely moved slowly and deliberately with little or no capacity for acrobatic leaping, presumably maintaining consistent powerful grasps on branches in both above-branch and inverted postures.
Objectives:
Comprehensive quantification of the shape and proportions of the medial tibial facet (MTF) of the talus (=astragalus) has been lacking for Primates and their closest relatives. In this study, aspects of MTF form were quantified and employed to test hypotheses about their functional and phylogenetic significance. The following hypotheses influence perceptions of primate evolutionary history but are due for more rigorous assessment: 1) A relatively large MTF distinguishes "prosimians" (strepsirrhines and tarsiers) from anthropoids and non-primate euarchontans; 2) the distinctive form of the "prosimian" MTF is a correlate of locomotor tendencies that emphasize use of vertical and small diameter supports in conjunction with inverted, abducted foot postures; and 3) the "prosimian" MTF form arose along the primate stem lineage and was present in the euprimate common ancestor.
Methods:
Three-dimensional (3D) scanning was used to create scale digital models of tali (n = 378 specimens, 122 species) from which three types of variables capturing aspects of MTF form were computed: 1) MTF area relative to body mass and ectal facet area; 2) MTF shape (elliptical vs. non-elliptical); and 3) MTF dorsal restriction on the talar body (i.e., extensive vs. minimal exposure of non-articular area). Data were analyzed using both phylogenetic and traditional comparative methods including Phylogenetic Generalized Least Squares, Ordinary Least Squares, ANCOVA, ANOVA, and Bayesian Ancestral State Reconstruction (ASR).
Results:
Extant "prosimians" are generally distinct from anthropoids and non-primate euarchontans in our quantitative representations of MTF form. MTF area (but not shape or dorsal restriction) correlates with fibular facet angle (FFa) of the talus, which has also been argued to reflect habitual pedal inversion. Among strepsirrhines, taxa that engage in grasp-leaping more frequently/effectively appear to have a relatively larger MTF than less acrobatic taxa. Directional models of evolutionary change better describe the phylogenetic distribution of MTF variation than do other models. ASR shows 1) little change in the MTF along the primate stem, 2) independent evolution of relatively large and dorsoplantarly deep MTFs in basal haplorhines and strepsirrhines, and 3) re-evolution of morphologies similar to non-euprimates in anthropoids.
Conclusions:
Results support the hypothesis that differences in MTF form between anthropoids and "prosimians" reflect greater use of inverted foot postures and grasp-leaping in the latter group. Although fossil "prosimians" do not have the extreme MTF dimensions that characterize many extant acrobatic leapers, these variables by themselves provide little additional behavioral resolution at the level of individual fossils due to strong phylogenetic signal. ASR suggests that some specialization for use of inverted foot postures (as required in a fine-branch niche) and modifications for grasp-leaping evolved independently in basal strepsirrhine and haplorhine lineages.
Background:
Molecular clock estimates of crown strepsirhine origins generally advocate an ancient antiquity for Malagasy lemuriforms and Afro-Asian lorisiforms, near the onset of the Tertiary but most often extending back to the Late Cretaceous. Despite their inferred early origin, the subsequent evolutionary histories of both groups (except for the Malagasy aye-aye lineage) exhibit a vacuum of lineage diversification during most part of the Eocene, followed by a relative acceleration in diversification from the late Middle Eocene. This early evolutionary stasis was tentatively explained by the possibility of unrecorded lineage extinctions during the early Tertiary. However, this prevailing molecular view regarding the ancient origin and early diversification of crown strepsirhines must be viewed with skepticism due to the new but still scarce paleontological evidence gathered in recent years.
Methodological/principal findings:
Here, we describe new fossils attributable to Djebelemur martinezi, a≈50 Ma primate from Tunisia (Djebel Chambi). This taxon was originally interpreted as a cercamoniine adapiform based on limited information from its lower dentition. The new fossils provide anatomical evidence demonstrating that Djebelemur was not an adapiform but clearly a distant relative of lemurs, lorises and galagos. Cranial, dental and postcranial remains indicate that this diminutive primate was likely nocturnal, predatory (primarily insectivorous), and engaged in a form of generalized arboreal quadrupedalism with frequent horizontal leaping. Djebelemur did not have an anterior lower dentition as specialized as that characterizing most crown strepsirhines (i.e., tooth-comb), but it clearly exhibited a transformed antemolar pattern representing an early stage of a crown strepsirhine-like adaptation ("pre-tooth-comb").
Conclusions/significance:
These new fossil data suggest that the differentiation of the tooth-comb must postdate the djebelemurid divergence, a view which hence constrains the timing of crown strepsirhine origins to the Middle Eocene, and then precludes the existence of unrecorded lineage extinctions of tooth-combed primates during the earliest Tertiary.
Dental topographic analysis is the quantitative assessment of shape of three-dimensional models of tooth crowns and component features. Molar topographic curvature, relief, and complexity correlate with aspects of feeding behavior in certain living primates, and have been employed to investigate dietary ecology in extant and extinct primate species. This study investigates whether dental topography correlates with diet among a diverse sample of living platyrrhines, and compares platyrrhine topography with that of prosimians. We sampled 111 lower second molars of 11 platyrrhine genera and 121 of 20 prosimian genera. For each tooth we calculated Dirichlet normal energy (DNE), relief index (RFI), and orientation patch count (OPCR), quantifying surface curvature, relief, and complexity respectively. Shearing ratios and quotients were also measured. Statistical analyses partitioned effects of diet and taxon on topography in platyrrhines alone and relative to prosimians. Discriminant function analyses assessed predictive diet models. Results indicate that platyrrhine dental topography correlates to dietary preference, and platyrrhine-only predictive models yield high rates of accuracy. The same is true for prosimians. Topographic variance is broadly similar among platyrrhines and prosimians. One exception is that platyrrhines display higher average relief and lower relief variance, possibly related to lower relative molar size and functional links between relief and tooth longevity distinct from curvature or complexity. Explicitly incorporating phylogenetic distance matrices into statistical analyses of the combined platyrrhine-prosimian sample results in loss of significance of dietary effects for OPCR and SQ, while greatly increasing dietary significance of RFI. Am J Phys Anthropol 153:29-44, 2014. © 2013 Wiley Periodicals, Inc.
The systematics of all adapiforms is reviewed at the generic and specific levels. A new classification is proposed for the 30 genera of adapiforms, containing three families: Notharctidae, Adapidae and Sivaladapidae; and one subfamily of uncertain affinities, the new Pronycticebinae. A stratophenetic schema summarizing the distribution and phylogenetic relationships of all European adapiforms, Cercamoniinae, Notharctinae and Adapidae, is given. The particular characters of the skull of Pronycticebus gaudryi warrant its isolation in a separate subfamily Pronycticebinae, nocturnal adapiforms which are of special significance for lemuriform ancestry. Agerinia might pertain to the same group. Four genera are proposed as adapids outside the European adapine radiation. Amphipithecinae and several other Asiatic genera of uncertain affinities are discussed.
Specialized acrobatic leaping has been recognized as a key adaptive trait tied to the origin and subsequent radiation of euprimates based on its observed frequency in extant primates and inferred frequency in extinct early euprimates. Hypothesized skeletal correlates include elongated tarsal elements, which would be expected to aid leaping by allowing for increased rates and durations of propulsive acceleration at takeoff. Alternatively, authors of a recent study argued that pronounced distal calcaneal elongation of euprimates (compared to other mammalian taxa) was related primarily to specialized pedal grasping. Testing for correlations between calcaneal elongation and leaping versus grasping is complicated by body size differences and associated allometric affects. We re-assess allometric constraints on, and the functional significance of, calcaneal elongation using phylogenetic comparative methods, and present an evolutionary hypothesis for the evolution of calcaneal elongation in primates using a Bayesian approach to ancestral state reconstruction (ASR). Results show that among all primates, logged ratios of distal calcaneal length to total calcaneal length are inversely correlated with logged body mass proxies derived from the area of the calcaneal facet for the cuboid. Results from phylogenetic ANOVA on residuals from this allometric line suggest that deviations are explained by degree of leaping specialization in prosimians, but not anthropoids. Results from ASR suggest that non-allometric increases in calcaneal elongation began in the primate stem lineage and continued independently in haplorhines and strepsirrhines. Anthropoid and lorisid lineages show stasis and decreasing elongation, respectively. Initial increases in calcaneal elongation in primate evolution may be related to either development of hallucal-grasping or a combination of grasping and more specialized leaping behaviors. As has been previously suggested, subsequent increases in calcaneal elongation are likely adaptations for more effective acrobatic leaping, highlighting the importance of this behavior in early euprimate evolution.
A laterally sloping fibular facet of the astragalus (=talus) has been proposed as one of few osteological synapomorphies of strepsirrhine primates, but the feature has never been comprehensively quantified. We describe a method for calculating fibular facet orientation on digital models of astragali as the angle between the planes of the fibular facet and the lateral tibial facet. We calculated this value in a sample that includes all major extant primate clades, a diversity of Paleogene primates, and nonprimate euarchontans (n = 304). Results show that previous characterization of a divide between extant haplorhines and strepsirrhines is accurate, with little overlap even when individual data points are considered. Fibular facet orientation is conserved in extant strepsirrhines despite major differences in locomotion and body size, while extant anthropoids are more variable (e.g., low values for catarrhines relative to non-callitrichine platyrrhines). Euprimate outgroups exhibit a mosaic of character states with Cynocephalus having a more obtuse strepsirrhine-like facet and sampled treeshrews and plesiadapiforms having more acute haplorhine-like facets. Surprisingly, the earliest species of the adapiform Cantius have steep haplorhine-like facets as well. We used a Bayesian approach to reconstruct the evolution of fibular facet orientation as a continuous character across a supertree of living and extinct primates. Mean estimates for crown Primatomorpha (97.9°), Primates (99.5°), Haplorhini (98.7°), and Strepsirrhini (108.2°) support the hypothesis that the strepsirrhine condition is derived, while lower values for crown Anthropoidea (92.8°) and Catarrhini (88.9°) are derived in the opposite direction. Am J Phys Anthropol 151:420-447, 2013.© 2013 Wiley Periodicals, Inc.
A well-preserved calcaneus referrable to Proteopithecus sylviae from the late Eocene Quarry L-41 in the Fayum Depression, Egypt, provides new evidence relevant to this taxon's uncertain phylogenetic position. We assess morphological affinities of the new specimen using three-dimensional geometric morphometric analyses with a comparative sample of primate calcanei representing major extinct and extant radiations (n = 58 genera, 106 specimens). Our analyses reveal that the calcaneal morphology of Proteopithecus is most similar to that of the younger Fayum parapithecid Apidium. Principal components analysis places Apidium and Proteopithecus in an intermediate position between primitive euprimates and crown anthropoids, based primarily on landmark configurations corresponding to moderate distal elongation, a more distal position of the peroneal tubercle, and a relatively "unflexed" calcaneal body. Proteopithecus and Apidium are similar to cercopithecoids and some omomyiforms in having an ectal facet that is more tightly curved, along with a larger degree of proximal calcaneal elongation, whereas other Fayum anthropoids, platyrrhines and adapiforms have a more open facet with less proximal elongation. The similarity to cercopithecoids is most plausibly interpreted as convergence given the less tightly curved ectal facets of stem catarrhines. The primary similarities between Proteopithecus and platyrrhines are mainly in the moderate distal elongation and the more distal position of the peroneal tubercle, both of which are not unique to these groups. Proteopithecus and Apidium exhibit derived anthropoid features, but also a suite of primitive retentions. The calcaneal morphology of Proteopithecus is consistent with our cladistic analysis, which places proteopithecids as a sister group of Parapithecoidea. Am J Phys Anthropol 151:372-397, 2013.© 2013 Wiley Periodicals, Inc.
Foot proportions, and in particular the lengthening of the tarsal elements, play a fundamental role in the discussion on the locomotor adaptations of Palaeogene primates. The elongation of the distal portion of the tarsus, particularly the anterior part of the calcaneus, is frequently interpreted as an adaptation to leaping and has played a fundamental role in the reconstruction of the locomotor adaptations of the earliest primates. Here, we report an allometric analysis of calcaneal proportions in primates and other mammals, in order to determine the actual differences in calcaneal proportions. This analysis reveals that primates as a group display a relatively longer distal calcaneus, relative to both total calcaneal length and body mass, when compared with other mammals. Contrary to current expectations, morphofunctional analysis indicates that a moderate degree of calcaneal elongation is not an adaptation to leaping, but it is merely a compensatory mechanism to recover the lost load arm (metatarsal length) when the foot adopts a grasping function, in order to maintain the same locomotor efficiency. Leaping can be inferred only when anterior calcaneal length departs from the scaling of non-specialized primate groups. The role of leaping on the inferred locomotor repertoire of earliest primates needs to be revised considering the results of this work.
Understanding the evolutionary history of living organisms is a central problem in biology. Until recently the ability to infer evolutionary relationships was limited by the amount of DNA sequence data available, but new DNA sequencing technologies have largely removed this limitation. As a result, DNA sequence data are readily available or obtainable for a wide spectrum of organisms, thus creating an unprecedented opportunity to explore evolutionary relationships broadly and deeply across the Tree of Life. Unfortunately, the algorithms used to infer evolutionary relationships are NP-hard, so the dramatic increase in available DNA sequence data has created a commensurate increase in the need for access to powerful computational resources. Local laptop or desktop machines are no longer viable for analysis of the larger data sets available today, and progress in the field relies upon access to large, scalable high-performance computing resources. This paper describes development of the CIPRES Science Gateway, a web portal designed to provide researchers with transparent access to the fastest available community codes for inference of phylogenetic relationships, and implementation of these codes on scalable computational resources. Meeting the needs of the community has included developing infrastructure to provide access, working with the community to improve existing community codes, developing infrastructure to insure the portal is scalable to the entire systematics community, and adopting strategies that make the project sustainable by the community. The CIPRES Science Gateway has allowed more than 1800 unique users to run jobs that required 2.5 million Service Units since its release in December 2009. (A Service Unit is a CPU-hour at unit priority).
The first metatarsal of living Primates is characterized by a well-developed peroneal process, which appears proportionally larger in prosimians than in anthropoids. A large peroneal process has been hypothesized to: 1) reflect powerful hallucal grasping, 2) act as a buttress to reduce strain from loads acting on the entocuneiform-first metatarsal joint during landing and grasping after a leap, and/or 3) correlate with differences in physiological abduction of the hallux. In this study, we address the latter two hypotheses by comparing the morphology of the peroneal process in 143 specimens representing 37 species of extant prosimians, platyrrhine anthropoids, and tupaiids (tree shrews) that engage in different locomotor behaviors. In particular, we compare taxa that vary in leaping frequency and hallucal abduction. Linear and angular measurements on the first metatarsal were obtained to evaluate differences in relative peroneal process thickness and length, first metatarsal abduction angle, and overall first metatarsal shape. Leaping frequency was significantly correlated only with relative peroneal process thickness within extant lorisoids. Relative process length was positively correlated with the angle of hallucal abduction within prosimians; this angle is significantly greater in prosimians than anthropoids. Multivariate analyses of metatarsal shape effectively separate species along phylogenetic lines, but not by locomotor behaviors. The hypothesis that the peroneal process on the first metatarsal reduces the loads on the entocuneiform-first metatarsal joint during landing after a leap is in part supported by data from extant lorisoids (i.e., slow quadrupedal lorises vs. leaping galagos). A peroneal process of greater length within prosimians may serve to increase the lever arm for the peroneus longus muscle in order to prevent hyper-abduction, followed by inversion in locomotor situations where the animal's weight is born on a highly divergent/abducted hallux.
The oldest euprimates known from India come from the Early Eocene Cambay Formation at Vastan Mine in Gujarat. An Ypresian (early Cuisian) age of ∼53 Ma (based on foraminifera) indicates that these primates were roughly contemporary with, or perhaps predated, the India-Asia collision. Here we present new euprimate fossils from Vastan Mine, including teeth, jaws, and referred postcrania of the adapoids Marcgodinotius indicus and Asiadapis cambayensis. They are placed in the new subfamily Asiadapinae (family Notharctidae), which is most similar to primitive European Cercamoniinae such as Donrussellia and Protoadapis. Asiadapines were small primates in the size range of extant smaller bushbabies. Despite their generally very plesiomorphic morphology, asiadapines also share a few derived dental traits with sivaladapids, suggesting a possible relationship to these endemic Asian adapoids. In addition to the adapoids, a new species of the omomyid Vastanomys is described. Euprimate postcrania described include humeri, radii, femora, calcanei, and tali, most of which show typical notharctid features and are probably attributable to asiadapines. Anatomical features of the limb elements indicate that they represent active arboreal quadrupedal primates. At least one calcaneus is proximally shorter and distally longer than the others, resembling eosimiids in this regard, a relationship that, if confirmed, would also suggest an Asian or southeast Asian faunal connection. Isolated teeth from Vastan Mine recently attributed to a new eosimiid, Anthrasimias gujaratensis, appear to provide that confirmation. However, their attribution to Eosimiidae is equivocal. They are similar to teeth here tentatively referred to Marcgodinotius, hence A. gujaratensis may be a junior synonym of M. indicus. Corroboration of eosimiids at Vastan requires more compelling evidence. Although definitive conclusions are premature, available evidence suggests that the Vastan adapoids, at least, were derived from western European stock that reached India near the Paleocene-Eocene boundary.
Since its introduction in 2001, MrBayes has grown in popularity as a software package for Bayesian phylogenetic inference using Markov chain Monte Carlo (MCMC) methods. With this note, we announce the release of version 3.2, a major upgrade to the latest official release presented in 2003. The new version provides convergence diagnostics and allows multiple analyses to be run in parallel with convergence progress monitored on the fly. The introduction of new proposals and automatic optimization of tuning parameters has improved convergence for many problems. The new version also sports significantly faster likelihood calculations through streaming single-instruction-multiple-data extensions (SSE) and support of the BEAGLE library, allowing likelihood calculations to be delegated to graphics processing units (GPUs) on compatible hardware. Speedup factors range from around 2 with SSE code to more than 50 with BEAGLE for codon problems. Checkpointing across all models allows long runs to be completed even when an analysis is prematurely terminated. New models include relaxed clocks, dating, model averaging across time-reversible substitution models, and support for hard, negative, and partial (backbone) tree constraints. Inference of species trees from gene trees is supported by full incorporation of the Bayesian estimation of species trees (BEST) algorithms. Marginal model likelihoods for Bayes factor tests can be estimated accurately across the entire model space using the stepping stone method. The new version provides more output options than previously, including samples of ancestral states, site rates, site d(N)/d(S) rations, branch rates, and node dates. A wide range of statistics on tree parameters can also be output for visualization in FigTree and compatible software.
The ∼37 million-year-old Birket Qarun Locality 2 (BQ-2), in the Birket Qarun Formation of Egypt's Fayum Depression, yields evidence for a diverse primate fauna, including the earliest known lorisiforms, parapithecoid anthropoids, and Afradapis longicristatus, a large folivorous adapiform. Phylogenetic analysis has placed Afradapis as a stem strepsirrhine within a clade of caenopithecine adapiforms, contradicting the recently popularized alternative hypothesis aligning adapiforms with haplorhines or anthropoids. We describe an astragalus from BQ-2 (DPC 21445C), attributable to Afradapis on the basis of size and relative abundance. The astragalus is remarkably similar to those of extant lorises, having a low body, no posterior shelf, a broad head and neck. It is like extant strepsirrhines more generally, in having a fibular facet that slopes gently away from the lateral tibial facet, and in having a groove for the tendon of flexor fibularis that is lateral to the tibial facet. Comparisons to a sample of euarchontan astragali show the new fossil to be most similar to those of adapines and lorisids. The astragali of other adapiforms are most similar to those of lemurs, but distinctly different from those of all anthropoids. Our measurements show that in extant strepsirrhines and adapiforms the fibular facet slopes away from the lateral tibial facet at a gradual angle (112-126°), in contrast to the anthropoid fibular facet, which forms a sharper angle (87-101°). Phylogenetic analyses incorporating new information from the astragalus continue to support strepsirrhine affinities for adapiforms under varying models of character evolution.
This book updates, summarizes and synthesizes past and current research regarding the origin of the Order Primates. When did Primates arise? To what group of mammals are they most closely related? What is the functional and adaptive meaning of their constellation of derived characteristics? The papers in this volume examine hypotheses that have dominated our notions regarding early primate evolution and by coupling this with an emergent body of novel evidence due to new fossil discoveries and technological and methodological advances, provide a long overdue multidisciplinary reanalysis of the suite of derived life history, socioecological, neural, visual, circumorbital, locomotor, postural and masticatory specializations of the first primates. This integrative neontological and paleontological perspective is critical for understanding major behavioral and morphological transformations during the later evolution of higher primate clades. Primate Origins: Adaptations and Evolution is ideal for advanced undergraduates, graduate students and professionals in the fields of primatology, anthropology, mammalogy, and paleontology.
The sixth primate from Messel is identified and described in detail. It is a juvenile nocturnal cercamoniine displaying large orbits and a highly reduced deciduous molar dentition. The specimen belongs to the new genus Godinotia n.g. that is based on 'Pronycticebus' neglectus from the 'untere Mittelkohle' (uMK) of the Geiseltal (Thalmann et al. 1989; Thalmann 1994) as the type species.
Primate evolutionary morphologists have argued that selection for life in a fine branch niche resulted in grasping specializations that are reflected in the hallucal metatarsal (Mt1) morphology of extant “prosimians”, while a transition to use of relatively larger, horizontal substrates explains the apparent loss of such characters in anthropoids. Accordingly, these morphological characters—Mt1 torsion, peroneal process length and thickness, and physiological abduction angle—have been used to reconstruct grasping ability and locomotor mode in the earliest fossil primates. Although these characters are prominently featured in debates on the origin and subsequent radiation of Primates, questions remain about their functional significance. This study examines the relationship between these morphological characters of the Mt1 and a novel metric of pedal grasping ability for a large number of extant taxa in a phylogenetic framework. Results indicate greater Mt1 torsion in taxa that engage in hallucal grasping and in those that utilize relatively small substrates more frequently. This study provides evidence that Carpolestes simpsoni has a torsion value more similar to grasping primates than to any scandentian. The results also show that taxa that habitually grasp vertical substrates are distinguished from other taxa in having relatively longer peroneal processes. Furthermore, a longer peroneal process is also correlated with calcaneal elongation, a metric previously found to reflect leaping proclivity. A more refined understanding of the functional associations between Mt1 morphology and behavior in extant primates enhances the potential for using these morphological characters to comprehend primate (locomotor) evolution. Am J Phys Anthropol, 2014. © 2014 Wiley Periodicals, Inc.
Questions surrounding the origin and early evolution of primates continue to be the subject of debate. Though anatomy of the skull and inferred dietary shifts are often the focus, detailed studies of postcrania and inferred locomotor capabilities can also provide crucial data that advance understanding of transitions in early primate evolution. In particular, the hand skeleton includes characteristics thought to reflect foraging, locomotion, and posture. Here we review what is known about the early evolution of primate hands from a comparative perspective that incorporates data from the fossil record. Additionally, we provide new comparative data and documentation of skeletal morphology for Paleogene plesiadapiforms, notharctines, cercamoniines, adapines, and omomyiforms. Finally, we discuss implications of these data for understanding locomotor transitions during the origin and early evolutionary history of primates. Known plesiadapiform species cannot be differentiated from extant primates based on either intrinsic hand proportions or hand-to-body size proportions. Nonetheless, the presence of claws and a different carpometacarpal joint form in plesiadapiforms indicate different grasping mechanics. Notharctines and cercamoniines have intrinsic hand proportions with extremely elongated proximal phalanges and digit rays relative to metacarpals, resembling tarsiers and galagos. But their hand-to-body size proportions are typical of many extant primates (unlike those of tarsiers, and possibly Teilhardina, which have extremely large hands). Non-adapine adapiforms and omomyids exhibit additional carpal features suggesting more limited dorsiflexion, greater ulnar deviation, and a more habitually divergent pollex than observed plesiadapiforms. Together, features differentiating adapiforms and omomyiforms from plesiadapiforms indicate increased reliance on vertical prehensile-clinging and grasp-leaping, possibly in combination with predatory behaviors in ancestral euprimates.
Common locomotor patterns within extant taxonomic groups appear to be evident within Anthropoidea. These common locomotor patterns, as well as the anthropoid fossil record, provide insights into anthropoid locomotor evolution. The locomotor pattern quadrupedalism-leaping (found today among non-ateline ceboids) appears to represent the earliest locomotor adaptation in anthropoid evolution. Atelines and catarrhines increase the frequency of climbing behavior relative to callitrichines, cebines, and pithecines. Here, foot anatomy is analysed to infer locomotor adaptation in extinct anthropoids and to evaluate these common locomotor patterns in terms of anthropoid locomotor evolution. Similarly, primitive versus derived features in catarrhine foot anatomy are analysed. The foot anatomy of Oligocene parapithecids and propliopithecids may not be suitably representative of the ancestral anthropoid or the ancestral catarrhine condition, respectively.
The study of 13 partial femora and 3 tibiae from late Eocene Quercy localities (France) confirms the distinction of the two adapinine genera Adapis and Palaeolemur. The femora come from both new (Rosières 2 and Escamps) and old collections (of uncertain provenance). They allow the distinction of 5 morphological groups, whose morphological characteristics are functionally explained. Adapis and Palaeolemur show strong similarities to some small living platyrrhines (Saimiri, Cebus, Aotus) and much less to lorisines. Type 1 and type 2 were probably branch walking and running forms, using climbing less frequently. Types 4 and 5 were probably less specialized for running and used climbing more frequently. These relatively close 4 types are interpreted as 4 species of Adapis. Type 3 is associated with the only species known from Escamps, Palaeolemur betillei. This last species appears to have been predominantly a climber, however, without the morphological specializations of the posterior limb associated with slow climbing in lorisines.
The late Eocene European adapid Adapis parisiensis shares many postcranial features with the extant Lorisinae, suggesting that it was a nonleaping, slow-moving arboreal quadruped. The slightly older Leptadapis magnus was a larger, more robustly built strepsirhine, similar in some ways to Varecia insignis. Both taxa are quite different postcranially from the American Eocene adapids Pelycodus, Notharctus, and Smilodectes, and from an earlier European adapid from Messel. A phylogenetic analysis of these post-cranial features argues against an ancestral relationship between these two adapine species and anthropoids or these two adapines and Lemuriformes. The similarities between Adapis and lorisines and Leptadapis and Varecia are considered to be convergences.Copyright © 1983 S. Karger AG, Basel
Most primates live in trees, and many of them have strikingly human-like hands and faces. Scientists who study primate evolution agree that these two facts must be connected in some way. The details, however, are a matter of debate. Early theories explained the human-like peculiarities of primates simply as arboreal adaptations. More recent accounts have traced the origins of these peculiarities to more specific ways of arboreal life, involving leaping locomotion, shrub-layer foraging, visually guided predation on insects, or fruit-eating.
Two new primate tali were discovered from the middle Miocene of South America at La Venta, Colombia. IGM-KU 8802 is similar in morphology toCallicebus andAotus, and is allocated to cf.Aotus dindensis, while IGM-KU 8803, associated with a dentition of a new cebine primate, is similar toSaimiri. Both tali differ from the other known fossil platyrrhine tali,Dolichocebus andCebupithecia, and increase our knowledge of the locomotor diversity of the La Venta primate fauna.
A new genus and species attributed to the tribe Anchomomyini is described from the early Late Eocene locality of Sossís (MP17a), one of the most important Paleogene fossil sites from the Iberian Peninsula. Nievesia sossisensis is characterized by its buccolingually compressed P(4) and its upper molars with no pericone, medium-sized hypocone, straight postcingulum and minuscule mesostyle, and the extremely reduced metacone on the M(3). Its lower dentition presents a P4 with an incipient metaconid, lower molars with no paraconid and a premetacristid closing the trigonid basin, and M3 with the trigonid wider than the talonid. Phylogenetic analyses suggest a close relationship between Nievesia and Mazateronodon, although the new genus is also related to Anchomomys and, to a lesser extent, Buxella and Periconodon. These analyses, which also include djebelemurines, no longer relate European anchomomyins with crown strepsirhines, and suggest their closer relationship with asiadapines and sivaladapids.
The grasping primate foot is one of the hallmark adaptations for the order Primates. Prosimian muscle and joint analysis indicates that there are two distinct primate grasping feet. The I–V opposable grasp, in which the hallux opposes the other four digits around a support, is the primitive grasp type utilized by cheirogaleids, lorisides, Daubentonia, and tarsiids. Lemurids and indriids, on the other hand, have a derived I–II adductor grasp, where the grasping action of the hallux and the second digit have been enhanced. This grasp seems to be in response to increasing body size and the use of vertical supports. North American adapids, which were large and possessed the I–V opposable grasp, were probably not able to utilize vertical supports frequently. The recognition of this innovative adaptation, the I–II adductor grasp, which is unique to Madagascar, extends our appreciation of prosimian locomotor capabilities.
More than one hundred undescribed foot elements of Cantius and other closely related notharctine adapids (7 species in all) from throughout the early Eocene (Wasatchian) Willwood Formation of the Bighorn Basin, Wyoming, have been analyzed. For four species (Cantius ralstoni, “Copelemur” feretutus, Cantius frugivorus, and? Pelycodus jarrovii) these represent the first described postcranial material. The clade of Cantius and allied genera in the Bighorn Basin includes several speciation events and both increases and decreases in body size. The largest species represented by tarsal remains (? Pelycodus jarrovii) is several times larger than the smallest, Cantius ralstoni. However, despite the number of species, temporal duration, and range of body size represented, there are no obvious changes in foot morphology as measured by various indices or by observation of qualitative features. This contrasts with the more obvious changes in dental features (e.g., development of hypocone and mesostyle) in the same group of species described by earlier authors. The fossil record of Cantius thus illustrates different kinds of evolutionary change in the dentition and tarsus. The dentition changes in both size and shape while the tarsus changes only in size. We describe significant differences in foot anatomy which distinguish notharctines from extant strepsirhines, including the nature of the articulations between the navicular and cuboid and the distal tarsus with the metatarsus. These features indicate that the fossil taxa are not particularly closely allied phylogenetically to either extant strepsirhines in general or lemurids in particular.
Several aspects of Eocene adapiform hands were studied. Terminal phalanges of Smilodectes and Adapis have a distal broadening and a proximal body similar to claw-bearing phalanges. The relative lengths of metacarpals one to three show little specialization in the Messel adapiform and Pronycticebus, reduction of the second metacarpal in Notharctus and Smilodectes, and the proportions of arboreal quadrupeds in Adapis. A group of long-digited fossils, including Notharctus, the Messel adapiform and Europolemur, probably approximates early euprimate hand proportions. Pronycticebus had longer metacarpals more similar to indriids, while Adapis has the shorter digits of an arboreal quadruped. These adapiforms had a divergent thumb, although the degree of divergence can be estimated only in Adapis (35-40° between the first and the second metacarpals). Primitive euprimates probably had distal phalanges with a claw-bearing like body, but with some distal broadening. The simiiform hand is probably not derived from a prosimian grasping hand, a view which seems to be corroborated by the mode of locomotion in Adapis and is in agreement with Napier's analyses.
Remarkable new fossil discoveries and intensive study of fossil evidence has led, during the past decade, and particularly the last few years, to exceptional advances and modifications in our understanding of early primate evolution. New insights have also come from research on extant primates, especially detailed anatomical, functional, and molecular studies. This review, however, focuses on the paleontological evidence. New fossils are spawning novel, sometimes controversial ideas about the relationships within and among primates and their allies—a situation that has caused temporary instability, but should eventually lead to elucidation, if not resolution, of outstanding problems.
The paleontological evidence pertaining to the evolution of the modern diversity in structure and function of primate hands is reviewed. A reconstructed digit ofPlesiadapis shows characters and functional capacities typical of an arboreal way of life. In euprimates, we describe the strepsirhine morphotype hand, characterized by a relatively high degree of pollical divergence, features of the ulnocarpal articulation that imply an enhanced capacity for ulnar deviation, and relatively long digits; this hand is specialized for grasping. Hand remains ofSmilodectes, Adapis and a Messel adapiform reveal a remarkable diversity in carpal structure achieved in these Eocene adapiforms, due to differing locomotor evolutionary pathways. The subfossil lemuriformsMegaladapis andPalaeopropithecus both show stereotyped (but different) grasping capabilities.
The simiiform morphotype hand combines a relatively low degree of pollical divergence, features of the ulnocarpal articulation that imply a limited capacity for ulnar deviation, and relatively long metacarpals and short digits. This type of hand anatomy is mechanically well-suited to arboreal palmigrade quadrupedalism. The hands ofPliopithecus andMesopithecus are generally monkey-like.Oreopithecus' hand fits with its presumed suspensory habits. The hand ofProconsul suggests palmigrade quadrupedalism and climbing.Australopithecus afarensis' hand remains primarily a branch-grasping organ, with indications of enhanced manipulatory abilities.Homo habilis andParanthropus robustus illustrate two lines of increased tool-use abilities.
The euprimate morphotype hand was elongated, had a short carpus and limited mobility, but the corresponding locomotor mode remains speculative. Considerations on hand evolution in some living primate groups are included in the final summary of hand evolution in primates.
Im Zuge einer detaillierten Beschreibung wird der sechste Primatenfund aus Messet (Franzen 1994) neu bestimmt. Es handelt sich um einen juvenilen nocturnalen Cercamoniinen mit einer großen Orbita und stark reduzierter
Milchmolarbezahnung. Er gehört zur neu aufgestellten GattungGodinotia n. g., welche sich auf „Pronycticebus“ neglectus aus der unteren Mittelkohle des Geiseltales (Thalmann et al. 1989;Thalmann 1994) als Typusart bezieht.
The sixth primate from Messel is identified and described in detail. It is a juvenile nocturnal cercamoniine displaying large
orbits and a highly reduced deciduous molar dentition. The specimen belongs to the new genusGodinotia n. g. that is based on“Pronycticebus” neglectus from the “untere Mittelkohle” (uMK) of the Geiseltal (Thalmann et al. 1989;Thalmann 1994) as the type species.
The HGL-50 locality, situated on the Glib Zegdou outlier in the Gour Lazib of Algeria (Hammada du Dra), is famous for having yielded several dental remains of primates dating from the late Early to the early Middle Eocene. These primates include Algeripithecus minutus, Azibius trerki and a new species of cf. Azibius (not described yet). Algeripithecus was widely acknowledged to be one of the oldest known anthropoids from Africa. However, very recent discoveries strongly suggest that Algeripithecus is closely related to Azibius and that both taxa are phylogenetically remote from the clade Anthropoidea. Algeripithecus and Azibius make up the family Azibiidae and appear as stem strepsirhines. Here we describe and analyse two ankle bones (tali) found in HGL-50. UM/HGL50-466 is a small left talus, which is appropriate in size to belong to A. trerki, while UM/HGL50-467 is a right talus, which is significantly larger and appropriate in size to belong to the new large species of cf. Azibius. Both tali exhibit a suite of features that resemble conditions primarily found in extinct and extant strepsirhine and adapiform primates; conditions that are consistent with the strepsirhine-like dentition characterizing azibiids. Functionally, these two tali indicate that Azibius species were engaged in a form of active arboreal quadrupedalism with some ability to climb and leap. Azibiids were rather small-bodied primates, approximating the size of some modern dwarf lemurs (Cheirogaleidae) and sportive lemurs (Lepilemuridae) from Madagascar. Given their small body-size and their talar morphology, living cheirogaleid lemurs, which are agile arboreal quadrupeds (with climbing, springing and branch running activities), might appear as good analogues for azibiids in terms of locomotor behaviour.
A well-preserved fossil talus [National Museum of Myanmar Primates (NMMP) 82] of a large-bodied primate is described from the late middle Eocene Pondaung Formation of central Myanmar. The specimen was collected at Thandaung Kyitchaung, a well-known amphipithecid primate-bearing locality near the village of Mogaung. NMMP 82 adds to a meager but growing sample of postcranial remains documenting the large-bodied primates of the Pondaung Formation. This new talus exhibits a suite of features that resemble conditions found in living and fossil haplorhine primates, notably anthropoids. As such, the phylogenetic signal deriving from the morphology of NMMP 82 conflicts with that provided by NMMP 20, a partial skeleton (including a fragmentary calcaneus) of a second large-bodied Pondaung primate showing undoubted adapiform affinities. Analysis subtalar joint compatibility in a hypothetical NMMP 82/NMMP 20 combination (talus/calcaneus) reveals a substantial degree of functional mismatch between these two tarsal bones. The functional incongruence in subtalar joint morphology between NMMP 20 and NMMP 82 is consistent with the seemingly divergent phylogenetic affinities of these specimens, indicating that two higher level taxa of relatively large-bodied primates are documented in the Pondaung Formation. On the basis of its size and morphology, we refer the NMMP 82 talus to the large-bodied amphipithecid Pondaungia. The occurrence of anthropoid-like tali in the Pondaung Formation obviates the need to invoke homoplasy to explain the shared, derived dental characters that are common to amphipithecids and undoubted anthropoids. Functionally, the NMMP 82 talus appears to have pertained to a primate that is engaged in active quadrupedalism in an arboreal environment along broad and subhorizontal branches. The primate taxon represented by NMMP 82 was capable of climbing and leaping, although it was not particularly specialized for either of these activities.