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Systematics and macroevolution of extant and fossil scalopine moles (Mammalia, Talpidae)
... However, the resolution of locomotor adaptations through time requires a well-resolved phylogeny. Numerous phylogenetic hypotheses have been proposed based on osteological, myological, and molecular data (Hutchison, 1976;Yates and Moore, 1990;Whidden, 2000;Motokawa, 2004;Shinohara et al., 2004;Cabria et al., 2006;Sánchez-Villagra et al., 2006;Bannikova et al., 2015;Schwermann and Thompson, 2015;Sansalone et al., 2018;Schwermann et al., 2019), but often they reveal more conflicts rather than resolve the problem. This creates additional problems regarding the establishment and composition of subfamilies and tribes (Hutchison, 1968;Yates, 1984;McKenna and Bell, 1997;Hutterer, 2005), with substantial confusion surrounding the phylogenetic placement and taxonomic assignment of fossil forms (Ziegler, 2003;2012;Klietmann et al., 2015;He et al., 2016;Sansalone et al., 2018). ...
... This character is also present in other tribes such as the Talpini, Urotrichini (Rzebik-Kowalska, 2014), and Scaptonychini (Skoczeń, 1980); therefore, it is not a reliable synapomorphy for the tribe Scalopini. Instead, researchers now rely on differences in dental characteristics to separate Scalopini talpids from other talpids (see Schwermann et al., 2019, S1 for a discussion of the dental formula). Recent geometric morphometric and phylogenetic analyses (e.g., Schwermann et al., 2019) have also placed Mioscalops within the Scalopini tribe, thus we do the same. ...
... Instead, researchers now rely on differences in dental characteristics to separate Scalopini talpids from other talpids (see Schwermann et al., 2019, S1 for a discussion of the dental formula). Recent geometric morphometric and phylogenetic analyses (e.g., Schwermann et al., 2019) have also placed Mioscalops within the Scalopini tribe, thus we do the same. ...
... The humerus of subterranean species displays a pattern of coordinated early ossification of the distal (muscular) and proximal (articular) regions when compared to other nonsubterranean taxa (Bicklemann et al. 2014). Furthermore, the humeri of moles are generally wellpreserved in the fossil record, allowing the inclusion of extinct taxa which are key to the accurate reconstruction of evolutionary transitions within the clade and the coverage of the realized morphospace (Ziegler, 1999;Schwermann et al., 2019;Castiglione et al. 2020). ...
... Because we included fossil taxa, we built our phylogenetic hypothesis based on maximum parsimony trees produced by cladistic analyses of previously published matrices of osteological characters (Sanchez-Villagra et al. 2006;Schwermann and Thompson, 2015;Hooker, 2016;Sansalone et al. 2018;Schwermann et al. 2019). The matrix includes 171 total characters (five unordered; ...
... Tables S1 and S2), all characters were equally weighted, and the topology was constrained following the hypothesis proposed by He et al. (2021). Some fossil species were too poorly represented to facilitate codification of a sufficient number of characters, hence we coded characters only for the 8 taxa represented by complete or near-complete material (Domninoides mimicus, Mygalea jaegeri, Proscapanus sansaniensis, Mioscalops isodens, M. ripafodiator, Leptoscaptor robustior, Yanshuella primaeva and Yunoscaptor scalprum) following the coding in Schwermann et al. (2019). The comparative analyses presented here were performed on a strict consensus tree generated from the four most parsimonious trees produced from a heuristic search and stepwise addition, with a random addition sequence of 1000 replicates. ...
The evolution of complex morphological structures can be characterized by the interplay between different anatomical regions evolving under functional integration in response to shared selective pressures. Using the highly derived humeral morphology of talpid moles as a model, here we test whether functional performance is linked to increased levels of evolutionary integration between humerus sub‐units and, if so, what the strength is of the relationship. Combining 2D geometric morphometrics, phylogenetic comparative methods and functional landscape modelling, we demonstrate that the high biomechanical performance of subterranean moles’ humeri is coupled with elevated levels of integration, whereas taxa with low performance values show intermediate or low integration. Theoretical morphs occurring in high‐performance areas of the functional landscape are not occupied by any species, and show a marked drop in covariation levels, suggesting the existence of a strong relationship between integration and performance in the evolution of talpid moles’ humeri. We argue that the relative temporal invariance of the subterranean environment may have contributed to stabilize humeral morphology, trapping subterranean moles in a narrow region of the landscape and impeding any attempt to reposition on a new ascending slope. This article is protected by copyright. All rights reserved
... The macroevolution of the Scalopini is more complex than generally acknowledged. Although the extant scalopines are now sparse and mainly distributed in North America, more than 14 fossil genera from the upper Oligocene have been found throughout Asia, Europe and North America, indicating a formerly high diversity and wide distribution (Schwermann et al., 2019). Morphological studies suggest that the Scalopini originated in Eurasia and had at least two back migrations to Eurasia (Sánchez-Villagra et al., 2006;Schwermann et al., 2019). ...
... Although the extant scalopines are now sparse and mainly distributed in North America, more than 14 fossil genera from the upper Oligocene have been found throughout Asia, Europe and North America, indicating a formerly high diversity and wide distribution (Schwermann et al., 2019). Morphological studies suggest that the Scalopini originated in Eurasia and had at least two back migrations to Eurasia (Sánchez-Villagra et al., 2006;Schwermann et al., 2019). The extant Gansu mole (Scapanulus oweni) was regarded as a migrator and the only relict species of the Scalopini in China. ...
... Thus, we suggest that the rapid uplift of the Himalayan-Tibetan Plateau and ensuing climate change led to the isolation and divergence of A. medogensis and Scapanulus oweni. Schwermann et al. (2019) hypothesized that scalopine moles migrated from North America into Asia at least twice via the Bering land bridge, and the earlier time (c. 15-16 Mya) represents the origin of Scapanulus oweni. ...
All scalopine moles are found in North America, except the Gansu mole (Scapanulus oweni), which is endemic to central-west China. In 2019, we collected two specimens of Scalopini on Mt Namjagbarwa in the eastern Himalayas, Tibet, China. We sequenced two mitochondrial (CYT B and 12S) and three nuclear (APOB, BRCA1 and RAG2) genes to estimate the phylogenetic relationships of the two moles, and also compared their morphology with other genera and species within the Scalopini. Both morphological and molecular analyses strongly suggest that the specimens represent a new monotypic genus and species, which are formally described here as Alpiscaptulus medogensis gen. et sp. nov. The dental formula of the new mole (44 teeth) is distinct from the Chinese Scapanulus oweni (36 teeth) and its hairy and pale brown tail is unique among species of the Scalopini. The Kimura-2-parameter (K2P) distances of CYT B between A. medogensis and the four recognized Scalopini genera range from 14.5% to 18.9%. A sister relationship between A. medogensis and Scapanulus oweni was strongly supported in the phylogenetic trees. The divergence between A. medogensis and Scapanulus oweni occurred in the mid-Miocene (c. 11.56 Mya), which corresponds with the rapid uplift of the Himalayan-Tibetan Plateau.
... For example, the lack of significant convergence between European (genus Talpa) and North-American moles may reflect the longstanding separation and phylogeographic histories of these two groups (Ziegler, 1999;Sánchez-Villagra et al., 2006;Schwermann et al., 2019). Scalopine moles went extinct in Europe during the Messinian salinity crisis (Krijgsman et al., 1999), whereas European mole (Talpini) diversity rose after the crisis ended, possibly exploiting the ecological niche left empty by the extinction of the Scalopini in Eurasia (Ziegler, 1999;van den Hoek Ostende and Fejfar, 2006). ...
Morphological similarity between biological structures in phylogenetically distant species is usually regarded as evidence of convergent evolution. Yet, phenotypic similarity is not always a sign of natural selection acting on a particular trait, therefore adaptation to similar conditions may fail to generate convergent lineages. Herein we tested whether convergent evolution occurred in the humerus of fossorial mammals, one of the most derived biological structures among mammals. Clades adapting to digging kinematics possess unusual, by mammalian standards, humeral shapes. The application of a new, computationally fast morphological test revealed a single significant instance of convergence pertaining to the Japanese fossorial moles (Mogera) and the North-American fossorial moles (Scalopini). Yet, the pattern only manifests when trade-off performance data (derived from finite element analysis) are added to shape data. This result indicates that fossorial mammals have found multiple solutions to the same adaptive challenge, independently moving around multiple adaptive peaks. This study suggests the importance of accounting for functional trade-off measures when studying morpho-functional convergence. We revealed that fossorial mammals, a classic example of convergent evolution, evolved multiple strategies to exploit the subterranean ecotope, characterized by different functional trade-offs rather than converging toward a single adaptive optimum.
... We digitized 22 landmarks and 14 semi-landmarks on the humerus and 12 landmarks and 26 semi-landmarks on the mandible ( Fig. 2a and b) using the tpsDig2 software [45]. The humeral and mandibular landmark configurations were derived from [40,[46][47][48] respectively. Semi-landmarks were used to capture the morphology of complex outlines where homologous anatomical points were missing. ...
Background:
Understanding the mechanisms promoting or constraining morphological diversification within clades is a central topic in evolutionary biology. Ecological transitions are of particular interest because of their influence upon the selective forces and factors involved in phenotypic evolution. Here we focused on the humerus and mandibles of talpid moles to test whether the transition to the subterranean lifestyle impacted morphological disparity and phenotypic traits covariation between these two structures.
Results:
Our results indicate non-subterranean species occupy a significantly larger portion of the talpid moles morphospace. However, there is no difference between subterranean and non-subterranean moles in terms of the strength and direction of phenotypic integration.
Conclusions:
Our study shows that the transition to a subterranean lifestyle significantly reduced morphological variability in talpid moles. However, this reduced disparity was not accompanied by changes in the pattern of traits covariation between the humerus and the mandible, suggesting the presence of strong phylogenetic conservatism within this pattern.
The Pliocene Konservat-Lagerstätten maar lake site of Camp dels Ninots (NE Iberian Peninsula) has recently delivered a partial skeleton of a mole (family Talpidae) with many elements in anatomical connection. At a first glance, molar and humerus size, geological time interval, and geographical location suggested that this specimen could correspond to Talpa minor . However, after some mechanical preparation of the clay block (matrix removal, consolidation, and cleaning) and a micro-CT scan, this excellently preserved specimen turned out to be an unknown species to science. The resulting 3D models of this new form, Vulcanoscaptor ninoti gen. et sp. nov., revealed some peculiar morphological traits in teeth, mandible, and postcranial elements, which according to the phylogenetic analysis carried out, would allocate this new species within the tribe Scalopini. This is surprising, because the representatives of this tribe are nowadays restricted to North America and Asia, and only some taxa had been previously reported in the Oligocene and Miocene fossil record from Europe. The postcranial construction of this specimen reveals a highly fossorial lifestyle supported by a complex forelimb structure. How such a specialized digging animal reached the maar lake sediments where it was finally preserved is still to be solved. Some hypotheses consider swimming abilities for this extinct species. Alternatively, this specimen could be the remaining portions of a floated or scavenged carcass whose remains fell into the lake and reached the anoxic bottom.
ELife digest
Understanding how extinct species are related to each other or to their living relatives is often a difficult task. Many extinct species have been identified only from incomplete fragments of some of their bones. However, even if complete skeletons have been found, determining the relationships between species can be tricky because researchers often have to rely solely on the shapes of the bones.
It is sometimes possible to retrieve DNA sequences from fossil bones. This is easier with younger fossils and those that have been recovered from cold environments. Ancient DNA sequences have been retrieved from only a few fossils older than 100,000 years, but such DNA sequences can be tremendously useful in determining how different species are related to each other.
Today there are three living elephant species: the African forest elephant, the African savanna elephant and the Asian elephant. However, there are many extinct elephant species. For example, the European straight-tusked elephant went extinct at least 30,000 years ago, although most of the fossils that have been discovered are at least 100,000 years old. Straight-tusked elephants are generally assumed to be closely related to the Asian elephant, but this conclusion had been based solely on reconstructing skeletons.
Meyer et al. have now obtained DNA sequences from fossils of four straight-tusked elephants ranging from around 120,000 to 240,000 years in age. These sequences were analysed to determine how straight-tusked elephants are related to the three living elephant species and the extinct mammoth, the DNA sequences for which can be found in public databases. The analyses revealed that straight-tusked elephants are in fact most closely related to the African forest elephant, not the Asian elephant as previously thought.
This result completely changes our picture of elephant evolution and suggests that it is extremely difficult to determine elephant relationships based on the shape of their skeleton alone. It also shows that the African elephant lineage was not restricted to the African continent (the place where all elephant lineages originated), but that it also left Africa.
Overall, the results presented by Meyer et al. confirm that DNA sequences are of critical importance for understanding the evolution of animals. Future research should include obtaining DNA sequences from additional extinct elephant species as well as careful re-evaluation of skeletal measurements for reconstructing elephant evolution.
DOI: http://dx.doi.org/10.7554/eLife.25413.002
The systematics of Geotrypus is among the most debated within Talpidae, but the recent development of quantitative methods for shape analyses allows us to provide a thorough reconsideration of Geotrypus spp. In the present study, we perform a systematic revision of the species Geotrypus minor from the early Oligocene of Germany using two-dimensional geometric morphometrics on the humerus, and cladistic analyses using two different character matrices. Our results suggest a distinct generic allocation for this species based on its unique humeral shape. Cladistic analyses reveal that G. minor has closer phylogenetic relationships with urotrichine shrew-moles than with other Geotrypus species or highly fossorial moles. Quantitative methods applied in this study support qualitative observations and fully justify a new generic allocation. In light of these results, Tegulariscaptor gen. nov. is proposed to encompass the material previously assigned to G. minor. http://zoobank.org/urn:lsid:zoobank.org:pub:8A839F1E-0EC8-4799-B3AE-1A4E54A95F0E © The Trustees of the Natural History Museum, London 2017. All rights reserved.
The adaptation to a particular function could directly influence the morphological evolution of an anatomical structure as well as its rates. The humeral morphology of moles (subfamily Talpinae) is highly modified in response to intense burrowing and fully fossorial lifestyle. However, little is known of the evolutionary pathways that marked its diversification in the two highly fossorial moles tribes Talpini and Scalopini. We used two-dimensional landmark-based geometric morphometrics and comparative methods to understand which factors influenced the rates and patterns of the morphological evolution of the humerus in 53 extant and extinct species of the Talpini (22 extant plus 12 extinct) and Scalopini (six extant plus 13 extinct) tribes, for a total of 623 humeri. We first built a synthetic phylogeny of extinct and extant taxa of the subfamily Talpinae based on all the available information from known phylogenies, molecular data, and age ranges of fossil records. We tested for evolutionary allometry by means of multivariate regression of shape on size variables. Evolutionary allometric trajectories exhibited convergence of humeral shape between the two tribes, even when controlling for phylogeny, though a significant differences in the evolutionary rates was found between the two tribes. Talpini, unlike Scalopini, seem to have reached a robust fossorial morphology early during their evolution, and their shape disparity did not change, if it did not decrease, through time. Furthermore, the basal Geotrypus spp. clearly set apart from the other highly fossorial moles, exhibiting a significant acceleration of evolutionary shifts toward higher degree of fossorial adaptation. Our observations support the hypothesis that the evolution of allometry may reflect a biological demand (in this case functional) that constrains the rates of evolution of anatomical structures.
The taxonomic position of the Japanese mountain mole (Euroscaptor mizura) was reassessed based on its external and skeletal morphologies. The muzzle shape of the intact individuals in this species exhibits a unique central groove on the ventral side, widening into a small naked portion at the tip. The naked portion becomes long and triangular in dried skin specimens, which was previously used as a specific characteristic of this species. It has the longest tail of talpine moles, with a rod shape that becomes narrow and lanceolate-shaped at the tip. The auditory ossicles include the malleus with a constricted neck and incus with a long processus brevis. It has a regressive mogeroid-type pelvis with two sciatic foramina, and a sacrum fused to the ischium. These morphological characteristics are not shared with continental Euroscaptor species, with which the Japanese mountain mole was originally classified based on the dental formula. Therefore, a new genus is proposed for this species.
The star nosed mole, Condylura cristata, due to its morphological and behavioural
peculiarities, has been deeply investigated by different authors. By contrast, very little
is known about the phylogenetic relationships, evolution and diversity of the fossil
members of this genus. In the present study we provide new insights about the fossil
specimens ascribed to Condylura taking into account systematic, palaeobiogeographical
and palaeoecological aspects. Further, we provide a re-description of a fossil Condylura
from the middle Miocene of Kazakhstan. We confirm that the Kazakh fossil
belongs to the genus Condylura, based on humeral morphological features, and we
discuss its implications and impact on the phylogenetic scenario and ecology of this
peculiar talpid genus. This specimen represents the earliest record of the genus, thus
suggesting an Eurasiatic origin instead of the most commonly accepted scenario of a
North American one. The presence of both plesiomorphic and apomorphic characters
in Condylura strongly supports the hypothesis that this genus could be considered as
sister clade of Talpinae.
The mammalian family Talpidae (moles, shrew moles, desmans) is characterized by diverse ecomorphologies associated with terrestrial, semi-aquatic, semi-fossorial, fossorial, and aquatic-fossorial lifestyles. Prominent specializations involved with these different lifestyles, and the transitions between them pose outstanding questions regarding the evolutionary history within the family, not only for living but also for fossil taxa. Here we investigate the phylogenetic relationships, divergence times, and biogeographic history of the family using 19 nuclear and two mitochondrial genes (~16 kb) from ~60% of described species representing all 17 genera. Our phylogenetic analyses help settle classical questions in the evolution of moles, identify an ancient (mid-Miocene) split within the monotypic genus Scaptonyx, and indicate that talpid species richness may be nearly 30% higher than previously recognized. Our results also uniformly support the monophyly of long-tailed moles with the two shrew mole tribes and confirm that the Gansu mole is the sole living Asian member of an otherwise North American radiation. Finally, we provide evidence that aquatic specializations within the tribes Condylurini and Desmanini evolved along different morphological trajectories, though we were unable to statistically reject monophyly of the strictly fossorial tribes Talpini and Scalopini.
Methods in historical biogeography have revolutionized our ability to infer the evolution of ancestral geographical ranges from phylogenies of extant taxa, the rates of dispersals, and biotic connectivity among areas. However, extant taxa are likely to provide limited and potentially biased information about past biogeographic processes, due to extinction, asymmetrical dispersals and variable connectivity among areas. Fossil data hold considerable information about past distribution of lineages, but suffer from largely incomplete sampling. Here we present a new dispersal–extinction–sampling (DES) model, which estimates biogeographic parameters using fossil occurrences instead of phylogenetic trees. The model estimates dispersal and extinction rates while explicitly accounting for the incompleteness of the fossil record. Rates can vary between areas and through time, thus providing the opportunity to assess complex scenarios of biogeographic evolution. We implement the DES model in a Bayesian framework and demonstrate through simulations that it can accurately infer all the relevant parameters.We demonstrate the use of our model by analysing the Cenozoic fossil record of land plants and inferring dispersal and extinction rates across Eurasia and North America. Our results show that biogeographic range evolution is not a time-homogeneous process, as assumed in most phylogenetic analyses, but varies through time and between areas. In our empirical assessment, this is shown by the striking predominance of plant dispersals from Eurasia into North America during the Eocene climatic cooling, followed by a shift in the opposite direction, and finally, a balance in biotic interchange since the middle Miocene.We conclude by discussing the potential of fossil-based analyses to test biogeographic hypotheses and improve phylogenetic methods in historical biogeography. © 2016 The Author(s) Published by the Royal Society. All rights reserved.
Geometric morphometrics (GM) and finite element analysis (FEA) are increasingly common techniques for the study of form and function. We show how principles of quantitative evolution in continuous phenotypic traits can link the two techniques, allowing hypotheses about the relative importance of different functions to be tested in a phylogenetic and evolutionary framework. Finite element analysis is used to derive quantitative surfaces that describe the comparative performance of different morphologies in a morphospace derived from GM. The combination of two or more performance surfaces describes a quantitative adaptive landscape that can be used to predict the direction morphological evolution would take if a combination of functions was selected for. Predicted paths of evolution also can be derived for hypotheses about the relative importance of multiple functions, which can be tested against evolutionary pathways that are documented by phylogenies or fossil sequences. Magnitudes of evolutionary trade-offs between functions can be estimated using maximum likelihood. We apply these methods to an earlier study of carapace strength and hydrodynamic efficiency in emydid turtles. We find that strength and hydrodynamic efficiency explain about 45% of the variance in shell shape; drift and other unidentified functional factors are necessary to explain the remaining variance. Measurement of the proportional trade-off between shell strength and hydrodynamic efficiency shows that throughout the Cenozoic aquatic turtles generally sacrificed strength for streamlining and terrestrial species favored stronger shells; this suggests that the selective regime operating on small to mid-sized emydids has remained relatively static.SUPPLEMENTAL DATA—Supplemental materials are available for this article for free at www.tandfonline.com/UJVPCitation for this article: Polly, P. D., C. T. Stayton, E. R. Dumont, S. E. Pierce, E. J. Rayfield, and K. D. Angielczyk. 2016. Combining geometric morphometrics and finite element analysis with evolutionary modeling: towards a synthesis. Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2016.1111225.
Twenty-one species of small mammals are recognized from the Observation Quarry fauna including four new species: The lipotyphlans Lanthanotherium observatum (Erinaceidae), Antesorex wilsoni (Soricidae), and Scalopoides hutchisoni (Talpidae), and the rodent Mioheteromys subterior (Heteromyidae). Due to more complete material, emended diagnoses are provided for the plesiosoricid Plesiosorex greeni Martin and Lim, 2004, and cricetid rodent Copemys lindsayi Sutton and Korth, 1995. Of the 21 species recognized, seven are unique to this faunal assemblage, six are restricted to the Hemingfordian, seven are known elsewhere only from the Barstovian or later, and one is known from both the Hemingfordian and Barstovian. The small mammals suggest that the Observation Quarry contains a transitional Hemingfordian-Barstovian fauna with a greater number of species from the latter, supporting an early Barstovian age.
New materials of the mole, Scapanulus oweni, are described from the Shanyangzhai Cave deposits of Qinhuangdao in China, which have yielded many vertebrate fossil assemblages referred to the Middle Pleistocene. The materials including 8 isolated upper teeth, 5 broken left mandibles, 9 isolated lower teeth, 4 humeri, and 3 toe bones. The parastyle of M1 is quite weak. The trigonid basins of the lower molars are closed or semi-closed. The m2 is largest, while the lengths of m1 and m3 are subequal. For the humeri, the scalopinae ridge is weakly developed, the fossa brachialis is similarly deep, the humerus is markedly overall slender, and the teres tuberculus is longer. The fossil Scapanulus oweni was first reported from north China. The toe bones of this fossil mole are first reported.
In the Miocene, the talpid diversity was much higher than today. Especially the semifossorial and ambulatory moles were farther distributed and more common. Here, the talpids from the Bavarian fissure filling Petersbuch 28 (Early Miocene, MN 3) are described. The uropsiline Desmanella engesseri Ziegler, 1985 is the most frequent species, followed by Myxomygale
hutchisoni (Ziegler, 1985), an urotrichine less specialized towards burrowing. The fossorial talpids Talpa sp. and Proscapanus
intercedens Ziegler, 1985 are represented by humeri, P. intercedens by a few teeth. Some teeth could not be determined to species level. Among the rich postcranial material, the humerus of Desmanella engesseri was found for the first time. Compared to other Miocene localities, Petersbuch 28 is unique in the dominance of only superficially burrowing and semifossorial talpids. In the time from MN 2 to MN 7 + 8 (Early to Middle Miocene), the fossorial talpids were less dominant during MN 2 and most of MN 3, became more frequent during MN 4 and were predominant from MN 5 onward.
A major goal of evolutionary studies is to better understand how complex morphologies are related to the different functions and behaviours in which they are involved. For example, during locomotion and hunting behaviour, the head and the eyes have to stay at an appropriate level in order to reliably judge distance as well as to provide postural information. The morphology and orientation of the orbits and cranial base will have an impact on eye orientation. Consequently, variation in orbital and cranial base morphology is expected to be correlated with aspects of an animal's lifestyle. In this study, we investigate whether the shape of the skull evolves in response to the functional demands imposed by ecology and behaviour using geometric morphometric methods. We test if locomotor habitats, diet, and activity pattern influence the shape of the skull in musteloid carnivorans using (M)ANOVAs and phylogenetic (M)ANOVAs, and explore the functional correlates of morphological features in relation to locomotor habitats, diet, and activity pattern. Our results show that phylogeny, locomotion and, diet strongly influence the shape of the skull, whereas the activity pattern seems to have a weakest influence. We also show that the locomotor environment is highly integrated with foraging and feeding, which can lead to similar selective pressures and drive the evolution of skull shape in the same direction. Finally, we show similar responses to functional demands in musteloids, a super family of close related species, as are typically observed across all mammals suggesting the pervasiveness of these functional demands.
The results of the first molecular study focused on the phylogenetic position of the Gansu mole, Scapanulus oweni are presented. The analysis based on sequences of the mitochondrial cytb gene and five nuclear genes supports the monophyly of the Scalopini tribe including S. oweni and shows that two highly fossorial talpid tribes, Talpini and Scalopini, are not immediate sister taxa. These results highlight the role of morphological parallelism as a potential source of conflict between molecular and morphology-based phylogenies in Talpidae.
The taxonomic validity of Talpa fossilis has been subject to a longstanding debate. Talpa fossilis has been considered as a chronospecies, stratigraphic species, and finally as junior synonym of Talpa europaea. In this study, the large humeral sample of T. fossilis and T. europaea from the Plio-Pleistocene of Hungary is re-investigated using a geometric morphometrics analysis. Furthermore, the differences in the static allometric slopes under the allometric constraint hypothesis were tested. The results indicate that T. fossilis and T. europaea have significant differences in both size and shape. The allometric slopes of T. fossilis and T. europaea were found to be different, revealing that the two taxa follow different patterns of shape modification according to size. In light of this evidence, T. fossilis and T. europaea are supported as two distinct species.
We describe four exceptionally preserved Miocene talpid specimens from Germany (representing Mygalea jaegeri, Proscapanus sansaniensis, and Geotrypus montisasini), expanding and amending the original descriptions based on micro-computed tomography (μ-CT) data. These specimens are scored into an enlarged version of the Sánchez-Villagra et al. (2006) character set, along with newly collected data for extant talpids and the fossil species Geotrypus antiquus, Domninoides mimicus, Eotalpa belgica, and E. anglica. The extant genus Scaptonyx is here resolved as the sister taxon to the American shrew-mole, Neurotrichus, and not as a close relative of the Talpini. Of the fossil talpids, Mygalea jaegeri is recovered as the sister taxon of extant desmans only in the context of genetic constraints: morphological data alone suggest that it represents a shrew-mole/desman-grade animal. Proscapanus sansaniensis is placed at the base of the Scalopini, whereas Domninoides mimicus is the sister taxon to Parascalops and Scapanulus. Geotrypus represents an early fossorial form, with G. antiquus retaining its position at the base of the Talpini, although G. montisasini's placement remains uncertain. Interestingly, the placement of these fossils causes character states more commonly associated with the semi-fossorial shrew-moles to be optimized to the root of the highly fossorial Talpini. Thus, despite the close relationship between Talpini and Scalopini based on morphological data, the fossil record provides evidence to support the independent evolution of extreme fossoriality in these groups. This finding is in agreement with genetic data sets, despite obvious topological differences.
The generic attribution of the Plio-Pleistocene Polish moles Neurotrichus? polonicus and
Neurotrichus? skoczeni has been questioned several times in the past. The fossil material
belonging to Neurotrichus? polonicus and Neurotrichus? skoczeni is re-evaluated here and a
new diagnosis is provided on the basis of qualitative considerations. In addition, a Geometric
Morphometric analysis of the humerus has been performed including both extant and extinct
Neurotrichini and Urotrichini taxa for comparison. Our results proved the unique morphology
of the Polish material suggesting a distinct taxonomic state. The morphological variations
evidenced by the humeral shape analysis agree with the observed qualitative differences and
support a new generic allocation. The new genus Rzebikia gen. nov. is proposed for all the
material previoulsly ascribed to Neurotrichus? polonicus and Neurotrichus? skoczeni.
Founder-event speciation, where a rare jump dispersal event founds a new genetically isolated lineage, has long been considered crucial by many historical biogeographers, but its importance is disputed within the vicariance school. Probabilistic modeling of geographic range evolution creates the potential to test different biogeographical models against data using standard statistical model choice procedures, as long as multiple models are available. I re-implement the Dispersal-Extinction-Cladogenesis (DEC) model of LAGRANGE in the R package BioGeoBEARS, and modify it to create a new model, DEC+J, which adds founder-event speciation, the importance of which is governed by a new free parameter, j. The identifiability of DEC and DEC+J is tested on datasets simulated under a wide range of macroevolutionary models where geography evolves jointly with lineage birth/death events. The results confirm that DEC and DEC+J are identifiable even though these models ignore the fact that molecular phylogenies are missing many cladogenesis and extinction events. The simulations also indicate that DEC will have substantially increased errors in ancestral range estimation and parameter inference when the true model includes +J. DEC and DEC+J are compared on 13 empirical datasets drawn from studies of island clades. Likelihood ratio tests indicate that all clades reject DEC, and AICc model weights show large to overwhelming support for DEC+J, for the first time verifying the importance of founder-event speciation in island clades via statistical model choice. Under DEC+J, ancestral nodes are usually estimated to have ranges occupying only one island, rather than the widespread ancestors often favored by DEC. These results indicate that the assumptions of historical biogeography models can have large impacts on inference and require testing and comparison with statistical methods.
Aim
I re‐evaluate the specific biogeographical significance of each of the land bridges (Beringia, Thulean and De Geer) in the Northern Hemisphere during the latest Cretaceous–early Cenozoic, showing that the Thulean and De Geer routes did not operate contemporaneously.
Location
Northern Hemisphere landmasses.
Methods
I review the recent climatic, sea‐level, geotectonic, palaeofloristic, and marine and terrestrial faunal data that have emerged since the establishment in the 1980s of the biogeographical concepts of the early Cenozoic Northern Hemisphere land bridges and present a synthesis supporting a revised scenario for early Cenozoic biogeographical development.
Results
Palaeogeographical and geotectonic data, supported by strong floral and faunal evidence, suggest that the palaeogeographical and chronological frames for the formation of all three land bridges are different from those originally proposed. Dispersal events via the causeways seem to have taken place during specific time intervals resulting from fluctuations in sea level and climate.
Main conclusions
The De Geer and Thulean routes were not contemporaneous. The former existed during the latest Cretaceous to the early Palaeocene, joining North America with Eurasia. The Thulean route became established well after the interruption of the De Geer route, offering a southerly connection between western Europe and North America in at least two episodes: c . 57 Ma and c . 56 Ma. The Bering route functioned in two warm periods: 65.5 Ma (coinciding with the De Geer route) and c . 58 Ma, during the Palaeocene (possible Eocene exposures are not considered here). The formation of the De Geer route explains faunal similarities between the Puercan and Torrejonian North American land mammal ages ( NALMA s) and the Shanghuan Asian land mammal age ( ALMA ). The Thulean route explains faunal similarities between the Clarkforkian (Cf1) and Wasatchian (Wa0, 1) NALMA s, and the Cernaysian and Neustrian ( PE I, II ) European land mammal ages. The Bering route explains faunal similarities between the Gashatan ALMA and the Tiffanian (Ti5) NALMA .
INTRODUCTION Used since its inception (Bowdich, 1821) as a “waste-basket” for morphologically disparate, putatively “primitive,” and generally ancient groups of small- to moderate-sized mammals, the traditional “Order Insectivora” of Simpson (1945) simply does not exist as an internally consistent or unified taxonomic grouping. This is true in both a morphological and a phylogenetic sense, and it reflects the considerable, though commonly understated, adaptive breadth of “insectivores.” Collectively, the “insectivorous” mammals are generally referred to by the appellation “primitive.” However, the cranial and dental specializations of hedgehogs (Erinaceidae), and shrews, moles, and apternodontids (Soricomorpha), are anything but primitive. Similarly, though fossil postcrania for most of these groups is poorly known among North American forms, those of moles are uniquely specialized by any definition. Most of the mammals discussed herein are relatively rare components of fossil vertebrate faunas. A few are known only from the type materials and many more only from incomplete upper or lower dentitions. Therefore, the dental anatomy of insectivorous mammals has both largely determined their diagnoses from related forms as well as played an instrumental role in their phylogenetic reconstruction. Notable exceptions to the constraints posed by limited knowledge of the anatomy of fossil forms are the importance of the anatomy of the humerus and the mandible to the taxonomy and phylogeny of, respectively, the moles and shrews. Of the groups of insectivorous mammals discussed herein, only Solenodontidae (including Nesophontidae), Talpidae, and Soricidae survive in North America.
Historical biogeography seeks to understand the distribution of biodiversity in space and time. The dispersal-extinction-cladogenesis (DEC) model, a likelihood-based model of geographic range evolution, is widely used in assessing the biogeography of clades. Robust inference of dispersal and local extinction parameters is crucial for biogeographic inference, and yet a major caveat to its use is that the DEC model severely underestimates local extinction. We suggest that this is mainly due to the way in which the model is constructed to allow observed species to transition into being present in no areas (i.e., null range). By prohibiting transitions into the null range in the transition rate matrix, we were able to better infer local extinction and support this with simulations. This modified model, DEC*, has higher model fit and model adequacy than DEC, suggesting this modification should be considered for DEC and other models of geographic range evolution.
Two geometrical figures, X and Y, in RK, each consisting of N landmark points, have the same shape if they differ by at most a rotation, a translation and isotropic scaling. This paper presents a model‐based Procrustes approach to analysing sets of shapes. With few exceptions, the metric geometry of shape spaces is quite complicated. We develop a basic understanding through the familiar QR and singular value decompositions of multivariate analysis. The strategy underlying the use of Procrustes methods is to work directly with the N x K co‐ordinate matrix, while allowing for an arbitrary similarity transformation at all stages of model formulation, estimation and inference. A Gaussian model for landmark data is defined for a single population and generalized to two‐sample, analysis‐of‐variance and regression models. Maximum likelihood estimation is by least squares superimposition of the figures; we describe generalizations of Procrustes techniques to allow non‐isotropic errors at and between landmarks. Inference is based on an N x K linear multivariate Procrustes statistic that, in a double‐rotated co‐ordinate system, is a simple but singular linear transformation of the errors at landmarks. However, the superimposition metric used for fitting, and the model metric, or covariance, used for testing, may not coincide. Estimates of means are consistent for many reasonable choices of superimposition metric. The estimates are efficient (maximum likelihood estimates) when the metrics coincide. F‐ratio and Hotelling's R2‐tests for shape differences in one‐ and two‐sample data are derived from the distribution of the Procrustes statistic. The techniques are applied to the shapes associated with hydrocephaly and nutritional differences in young rats.
The star nosed mole, Condylura cristata, due to its morphological and behavioural
peculiarities, has been deeply investigated by different authors. By contrast, very little
is known about the phylogenetic relationships, evolution and diversity of the fossil
members of this genus. In the present study we provide new insights about the fossil
specimens ascribed to Condylura taking into account systematic, palaeobiogeographical
and palaeoecological aspects. Further, we provide a re-description of a fossil Condylura
from the middle Miocene of Kazakhstan. We confirm that the Kazakh fossil
belongs to the genus Condylura, based on humeral morphological features, and we
discuss its implications and impact on the phylogenetic scenario and ecology of this
peculiar talpid genus. This specimen represents the earliest record of the genus, thus
suggesting an Eurasiatic origin instead of the most commonly accepted scenario of a
North American one. The presence of both plesiomorphic and apomorphic characters
in Condylura strongly supports the hypothesis that this genus could be considered as
sister clade of Talpinae.
Remains of Talpidae (Soricomorpha, Mammalia) from nine Pliocene and Early Pleistocene localities [Podlesice (MN14), We{ogonek}że 1 (MN15) and 2 (MN15/MN16), Re{ogonek}bielice Królewskie 1A and 2 (MN16), Kielniki 3B, and Zamkowa Dolna Cave A (MN17), Kadzielnia 1 (MN17 or MN17/Q1) and Zamkowa Dolna Cave C (Q2)] located in Poland are reviewed. One new genus Skoczenia n. gen. and one new species Quyania europaea n. sp. are described. The list of Talpidae species from the Pliocene and Early Pleistocene of Poland now includes Condylura kowalskii, C. izaballae, Parascalops fossilis?Scalopoides sp?Neurotrichus polonicus? N. skoczeni, Quyania europaea n. sp., and Skoczenia copernici n. gen. Where necessary, previously described specimens were reevaluated and redescribed, and new illustrations were added. The systematic position, distribution, and number of species in each of the localities are discussed.
The latest Miocene age localities of Ertemte 2 and Harr Obo 2 have produced more than 1 100 determinable soricid remains. Nine species representing seven genera are recognized. Six species and three genera are described as new: Sorex minutoides n. sp., S. ertemteensis n. sp., Alloblarinella sinica n. g., n. sp., Paenepetenyia zhudingi n. g., n. sp., Cokia kowalskae n. g., n. sp., and Paenelimnoecus obtusus n. sp. Two previously described species from Ertemte l are transferred to other genera, Crocidura kormosi Schlosser 1924 to Zelceina and Neomys inexspectatus Schlosser 1924 to Paranourosorex. The soricid faunas have strong affinities with European Neogene faunas. -from Author
The oldest talpid, Eotalpa, was previously known only from isolated cheek teeth from the European late Middle Eocene to earliest Oligocene. Screenwashing of Late Eocene sediments of the Hampshire Basin, UK, has yielded cranial and postcranial elements: maxilla, dentary, ulna, metacarpals, distal tibia, astragalus, calcaneum, metatarsals and phalanges. In addition to M1-2 myotodonty, typical talpid features are as follows: ulna with long medially curved olecranon and deep abductor fossa and astragalar body with lateral process. However, Eotalpa retains certain soricid-like primitive states (M1 preparacrista, P4 with prominent mesiolingual protocone lobe, strongly angled astragalar neck and calcaneum with no space for a cuboid medial process) not found in modern talpids. Eotalpa is more derived than the most primitive living talpid Uropsilus in having lost the M1-2 talon shelf, developed a convex radial facet on the ulna, an incipient proximal olecranon crest, relatively shorter metapodials and depressed manual unguals. Its astragalus with medial trochlear ridge taller than the lateral one and massive medial plantar process is typical of the Lipotyphla. Eotalpa lacks synostosis of tibia and fibula, found in other Talpidae, Soricidae and Erinaceidae, suggesting that synostosis in these groups has been independently acquired. Cladistic analysis places Eotalpa as stem member of the Talpidae and shows that much homoplasy arose during the early evolution of the family. Ground dwelling in Eotalpa is indicated by the following: astragalus with a medially dipping head, curved in a single plane; calcaneum with distal peroneal process and strongly overlapping ectal and sustentacular facets; and matching sized ectal and sustentacular facets on calcaneum and astragalus. These features would have restricted ankle mobility. Ungual and metatarsal shape and ulnar structure suggest a primitive stage in fossorial evolution and argue against a semiaquatic precursor stage in talpid fossoriality. Shrew-moles may represent a reversal to surface foraging rather than an intermediate stage in fossoriality.
The enigmatic Early Miocene fossorial mammal Mesoscalops montanensis shows one of the most modified humeri among terrestrial mammals. It has been suggested, on qualitative considerations, that this species has no extant homologues for humerus kinematics and that, functionally, the closest extant group is represented by Chrysochloridae. We combine here three dimensional geometric morphometrics, finite element analysis and phylogenetic comparative methods to explore the shape and mechanical stress states of Mesoscalops montanensis as well as of extant and extinct Talpidae and Chrysochloridae under realistic digging simulations. Evolutionary convergence analyses reveal that the shape of Mesoscalops montanensis represents a unique morphology in the context of fossorial mammals and that its functional performance, albeit superficially similar to that of extant Chrysochloridae, still represents a nonconvergent optimum for adaptation to digging. J. Morphol., 2015. © 2015 Wiley Periodicals, Inc.
© 2015 Wiley Periodicals, Inc.
Four humeri, two from the locality of Podlesice (early Pliocene, early Ruscinian MN 14) and two from Weze 1 A (Pliocene, Ruscinian MN 15) are the basis for description of a new species of Parascalops fossilis sp. n. All the Talpidae species described belong to the recent North American endemic genera and appeared as single species exclusively. The problem of probable migration or development of convergent lines is discussed. -Author
— We studied sequence variation in 16S rDNA in 204 individuals from 37 populations of the land snail Candidula unifasciata (Poiret 1801) across the core species range in France, Switzerland, and Germany. Phylogeographic, nested clade, and coalescence analyses were used to elucidate the species evolutionary history. The study revealed the presence of two major evolutionary lineages that evolved in separate refuges in southeast France as result of previous fragmentation during the Pleistocene. Applying a recent extension of the nested clade analysis (Templeton 2001), we inferred that range expansions along river valleys in independent corridors to the north led eventually to a secondary contact zone of the major clades around the Geneva Basin. There is evidence supporting the idea that the formation of the secondary contact zone and the colonization of Germany might be postglacial events. The phylogeographic history inferred for C. unifasciata differs from general biogeographic patterns of postglacial colonization previously identified for other taxa, and it might represent a common model for species with restricted dispersal.
Two geometrical figures, X and Y, in RK, each consisting of N landmark points, have the same shape if they differ by at most a rotation, a translation and isotropic scaling. This paper presents a model-based Procrustes approach to analysing sets of shapes. With few exceptions, the metric geometry of shape spaces is quite complicated. We develop a basic understanding through the familiar QR and singular value decompositions of multivariate analysis. The strategy underlying the use of Procrustes methods is to work directly with the N × K co-ordinate matrix, while allowing for an arbitrary similarity transformation at all stages of model formulation, estimation and inference. A Gaussian model for landmark data is defined for a single population and generalized to two-sample, analysis-of-variance and regression models. Maximum likelihood estimation is by least squares superimposition of the figures; we describe generalizations of Procrustes techniques to allow non-isotropic errors at and between landmarks. Inference is based on an N × K linear multivariate Procrustes statistic that, in a double-rotated co-ordinate system, is a simple but singular linear transformation of the errors at landmarks. However, the superimposition metric used for fitting, and the model metric, or covariance, used for testing, may not coincide. Estimates of means are consistent for many reasonable choices of superimposition metric. The estimates are efficient (maximum likelihood estimates) when the metrics coincide. F-ratio and Hotelling's T2-tests for shape differences in one- and two-sample data are derived from the distribution of the Procrustes statistic. The techniques are applied to the shapes associated with hydrocephaly and nutritional differences in young rats.