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We describe cranial, mandibular, and dental remains of five individuals of the giant mustelid Eomellivora piveteauiOzansoy, 1965, from the late Miocene (MN10) site of Cerro de los Batallones (Madrid, Spain)—the first complete cranial remains recorded for this species and the most complete remains of the genus. This new sample enables a review of the systematic status of Eomellivora, leading us to accept as valid the species E. piveteauiOzansoy, 1965, E. wimaniZdansky, 1924, E. ursogulo (Orlov, 1948), and E. hungaricaKretzoi, 1942. Our phylogenetic hypothesis indicates that Eomellivora is the sister taxon of the extant Mellivora capensis and E. piveteaui had a common ancestor within the crown group E. wimani—E. ursogulo. Eomellivora piveteaui was specialized for a more hypercarnivorous diet than the largest extant terrestrial mustelids, although it also had some derived bone-crushing adaptations. Eomellivora piveteaui had an active predatory role in the late Miocene carnivore faunas, exploiting both small and relatively large prey.
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 semifossorial 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.
Cranial material of the dicynodont Endothiodon from the middle fossiliferous horizon of the Permian Ruhuhu Formation (Ruhuhu Basin, Tanzania) is described as a new species, E. tolani. Endothiodon tolani is distinguished from other Endothiodon species by the absence of a pineal boss and the presence of tusks in most specimens. Although some parts of the Ruhuhu Formation probably correlate with the Eodicynodon or Tapinocephalus assemblage zones of the South African Karoo Basin, it is uncertain whether E. tolani is older than E. bathystoma or E. mahalanobisi. There is less evidence for extensive anteroposterior translation of the mandible in E. tolani than in other dicynodonts. The jaw joint is specialized for allowing some medial-lateral motion. Mastication involved unilateral chewing. Flexure of the postdentary bones relative to the fused dentaries permitted the posterolaterally directed rows of teeth on one side of the skull and mandible to move past one another. The long tooth rows and prominent horn-covered ridges and grooves on the palate and mandible of Endothiodon are unique among dicynodonts. Comparisons with other taxa suggest that its feeding system may have been specialized for cutting three-dimensional objects such as stems or rhizomes. The dicynodont feeding system is very stereotyped throughout the clade's history, but Endothiodon escaped the constraints that affected other dicynodonts, allowing it to evolve a unique skull morphology. This evolutionary flexibility did not translate into high taxonomic richness (we recognize only three species of Endothiodon), but Endothiodon was able to achieve high levels of relative abundance in some basins.
A new species of the phlyctaeniid arthrodire genus Groenlandaspis from the upper Famennian of Belgium is described. The remains of Groenlandaspis potyi, sp. nov., consist of dissociated thoracic armor elements, but the specimen designated to be the holotype displays the median dorsal, anterior, and posterior dorsolateral plates in articulation. Though incomplete, the new species is characterized by an equilateral triangle-shaped median dorsal plate, a protruding posterodorsal apron of the posterior dorsolateral plate behind the overlap area for the median dorsal plate, and an overall lack of ornamentation. Groenlandaspis potyi, sp. nov., constitutes the second occurrence of a Groenlandaspis species in continental Europe after the description of Groenlandaspis thorezi from upper Famennian quarries of Belgium. Another probable new species of Groenlandaspis is also described, though of unknown locality and horizon; it can, however, be deduced to be from the upper Famennian of Belgium without more precision. Together with some unpublished material of groenlandaspidids from the Famennian tetrapod-bearing locality of Strud, this material highlights the richness of Groenlandaspididae diversity in Belgium. The discovery of Groenlandaspis potyi, sp. nov., in Belgium reinforces the Famennian global distribution of this genus during this period. Also, because these organisms have been considered as nonmarine indicators, this material is another argument pleading for close relationships between Euramerica and Gondwana around the Frasnian—Famennian boundary.
The basal ornithopod Oryctodromeus cubicularis was described as burrowing due to its discovery in a burrow structure, and the presence of several morphological features considered consistent with burrowing. Using traditional and geometric morphometric analyses, the morphology of the humerus and scapula of ornithopods, basal ornithischians, and marginocephalians was analyzed to describe and characterize quantitatively the differences between Oryctodromeus and other ornithopods. These differences were then compared with the morphological adaptations for digging in mammals, because there are no adequate analogues for burrowing in extant archosaurs. A canonical variates analysis was also conducted on the geometric morphometric data to determine if phylogeny impacted morphological trends. The humerus of Oryctodromeus is slightly more robust than other basal ornithopods, indicating an adaptation for increased force applied to the humerus. The scapula provides the most compelling morphological support for digging in Oryctodromeus. The large acromion process and prominent scapular spine of Oryctodromeus, as well as the large posteroventrally expanded scapular blade, distinguish the scapula of Oryctodromeus from those of other ornithopods and would have provided surface areas for the attachment of the supracoracoideus, deltoideus clavicularis, and deltoideus scapularis muscles, the latter of which is important in digging in mammals. These features provide evidence for specialization for producing burrows by scratch digging.
The new species, Sivacobus sankaliai, from an assemblage dated <200 ka near Gopnath, northwestern India, constitutes the only record of the bovid tribe Reduncini (waterbuck and allies) outside Africa within ≤500 ka. The previous Asian reduncine record was assigned to at least six genera, with the latest known record from the Siwalik Pinjor Formation (India and Pakistan, ca. 2.7–0.6 Ma) and probably ≥1.7 Ma. Finding this unexpectedly late Asian reduncine prompted tests of two hypotheses: (1) the Gopnath form derives directly from an African lineage following immigration since 500 ka. (2) It is the last known survivor of an Asian monophyletic group. The evidence supports the second hypothesis. We find that Asian Plio—Pleistocene reduncines belong to only one genus, Sivacobus, of ≥3 Ma duration, and to only two species up to Pinjor times, S. palaeindicus and S. patulicornis, with now a third and later Pleistocene species added. We give a revised diagnosis of Sivacobus. There is a close, and probable sister-group, relationship of Sivacobus with Adenota, the African crown kob clade. Sivacobus arose from the same African ancestor as the kobs, which emigrated from Africa ca. 3.5 Ma ago and endured in Asia for ≥3 Ma. The African sister group survived to the present, whereas the Asian one almost did. The S. sankaliai discovery has resulted not only in an increase in morphological, taxonomic, and geographic diversity of the Asian Reduncini, but also—and importantly—in a significant extension of their duration.
Plotopterids are penguin-like, wing-propelled birds with controversial phylogenetic affinities. They are usually regarded as closely related to Suloidea (gannets, cormorants, and allies), with the penguin-like features considered to be of convergent origin. However, it has also been proposed that the similarities shared by plotopterids and penguins are due to common ancestry. An in-depth assessment of plotopterid affinities has been hampered by the fact that very little data about the skull of these birds were available. New fossils of Tonsala from the Oligocene Pysht Formation in Washington State (U.S.A.) include the first well-preserved cranial remains of this taxon. They show that although plotopterids share derived cranial features with members of Suloidea that are absent in species of Sphenisciformes (penguins), they lack diagnostic derived features of the representatives of crown group Suloidea. To assess the affinities of plotopterids, we performed a phylogenetic analysis that included, for the first time, early stem group representatives of Sphenisciformes, resulting in a sister-group relationship between Plotopteridae and Suloidea. Intriguingly, however, our reanalysis of the emended data of a more comprehensive recent analysis that supported a position of Plotopteridae within Suloidea recovered a sister-group relationship between Plotopteridae and Sphenisciformes. Although cranial morphology challenges the hypothesis of close affinities between plotopterids and penguins, more data on early stem lineage representatives of penguins are needed for a robust placement of Plotopteridae relative to Sphenisciformes.
We describe here Vulpes mathisoni, sp. nov., a new species of fox from the Mursi Formation of Ethiopia, dated to ca. 4 Ma., based upon a complete cranium with mandible. It is similar in size to V. pallida and resembles this species in several aspects, but the skull is narrower, the muzzle more slender, P4 has a weak protocone, M2 has a large metacone and a distinct, strong metaconule, m1 has a talonid with five distinct cuspids, and m2 has a strong mesial cingulum. Vulpesmathisoni, sp. nov., is probably an early member of a southern Afro-Indian clade that minimally includes V. pallida, V.chama, and V. bengalensis, pushing back its divergence from the Holarctic clade(s) to at least 4 Ma. We observe that, in sharp contrast to the Holarctic realm, the southern Afro-Indian one virtually lacks carnivorous small canids.
The Eocene through Miocene Cypress Hills Formation of Saskatchewan and Alberta has been the basis of studies on sedimentology, paleobotany, herpetofauna, avifauna, and mammalian local faunas. We describe the ichthyofauna from the Eastend area of the formation, representing late Eocene Chadronian to early Oligocene Whitneyan deposits. This fauna is diverse, including at least 14 fish taxa: Lepisosteus, Amiinae, aff. Hiodon, at least three cypriniforms among which is a Ptychocheilus-like leuciscine and at least one catostomid, two ictalurids, both ascribed to Astephus, a probable salmoniform, an amblyopsid-like percopsiform, Mioplosus, a probable moronid, a centrarchid, and at least one other perciform of uncertain affinity. The formation may therefore represent the first fossil record of the Amblyopsidae, and the first North American occurrence of the Moronidae. The composition of the ichthyofauna suggests higher temperatures during the Eocene—Oligocene transition than at present. Paleotemperatures similar to those of the Gulf Coast of the United States are indicated by the present ranges of several taxa, as well as by the large sizes attained by some of these fishes. The high relative abundance of abraded ictalurid material representing small individuals suggests that much of the formation was deposited in shallow, hypoxic floodplain pools that may have seasonally dried out. However, the large sizes attained by some taxa and the diversity of the fauna as a whole indicate that the neighboring aquatic environments were diverse, with well-oxygenated, vegetated, permanent, and deep-water environments. This suggests the presence of a mosaic of conditions, such as is found in large floodplains.
Moythomasia is one of the most speciose and completely known of all Devonian actinopterygian genera and has been incorporated into numerous phylogenetic studies. However, several species remain incompletely documented despite being known from excellent fossil material. Specimens from the Late Devonian of Germany and Australia are described herein. A form from Bergisch Gladbach, Germany, previously described by Jessen as Moythomasia cf. striata, is recognized as a new species: M. lineata, sp. nov. Newly prepared specimens of Moythomasia durgaringa from the Gogo Formation, Western Australia, allow for the first rigorous full-body reconstructions of this species. Aspects of the dermal skeleton and body shape of this form are updated over previous descriptions. The genus is currently problematic owing to the highly fragmentary nature of the type species, M. perforata from Kokenhusen; however, it is considered provisionally valid owing to distinctive cranial ornamentation. The three completely known species (M. durgaringa, M. nitda, and M. lineata, sp. nov.) do not share any unique squamation-based characters exclusive to other Devonian actinopterygians, invalidating purely scaled-based referrals to this genus.
Cranial and dental remains of the middle to early late Miocene macropodid kangaroo, Ganguroo robustiter, sp. nov., are described. Postcranial remains of G. robustiter were previously described as referable to G. bilamina. Ganguroo robustiter is more robust (approximately 20% larger) and more derived than G. bilamina and G. bites, in having a larger m4, a well-developed posterolingual ridge and lingual cingulum on P3, a longer P3/p3, and no stylar cusp C on M3–M4. We used previously published data matrices to analyze the phylogenetic relationship of G. robustiter. Both phylogenetic analyses, using craniodental and postcranial characters, place G. robustiter within Macropodidae, as the sister taxon to sthenurines and macropodines. Species of Ganguroo are not found to be monophyletic despite their extreme similarity in character scores. This may be due to the large amount of missing data for G. bilamina and G. bites for which no postcranial remains have been identified. Phylogenetic results are ambiguous, recovering unresolved trees with low bootstrap values, but the generic assignment of these taxa is maintained because they are remarkably similar. Species of Ganguroo may represent a phyletic lineage, with species increasing in size and losing cusp/cuspids on their premolars through time, which appears to coincide with a broader record of changing vegetation and climates through the middle Miocene.
The holotype of the sauropod dinosaur Rebbachisaurus garasbae was discovered in infra-upper Cenomanian horizons of the Kem Kem region of southeastern Morocco in the 1940s and 1950s. The original materials included part of a vertebral column, some of which was found in articulation, and a scapula, a humerus, and an ischium. Of these remains, only the scapula and one of the dorsal vertebrae have been described, but in abbreviated form. Following complete preparation of the partial skeleton, careful examination and fitting of scores of fragments collected with these materials, and computed tomography imaging of the most complete vertebra, we present a complete description of the holotype of Rebbachisaurusgarasbae. Our description identifies several autapomorphies of the dorsal and caudal vertebrae, both relating to the shape of the vertebrae and the architecture of their laminae. Based on our reassessment of its anatomy, Rebbachisaurus is recovered as a member of an Afro-European clade that includes Nigersaurus and Demandasaurus. Due to the large size of one of its dorsal vertebrae (ca. 1.45 m tall), Rebbachisaurus has been considered to be a large sauropod. The size of the vertebral centra and the length and cross-sectional area of the humerus of Rebbachisaurus, however, indicate this individual weighed 7915–12,015 kg, which is slightly larger than Amargasaurus but comparable in size to some individuals of Dicraeosaurus. The dorsal vertebrae of Rebbachisaurus and other rebbachisaurids have been suggested to be highly mobile, but results suggest that anatomical features of the vertebrae actually limited rotation and increased resistance to dorsoventrally directed forces applied to the transverse processes.
Jurassic fishes from the Southern Hemisphere are poorly known in comparison with those of the Northern Hemisphere. The Tithonian (Late Jurassic) deposits of Argentina have yielded a rich and taxonomically diverse ichthyofauna. However, these fishes have been only partially described and need to be revised or studied. In this paper, the putative ichthyodectiform actinopterygian Notodectes argentinus is redescribed. The holotype comes from the Vaca Muerta Formation, in the southwestern part of Mendoza Province, Argentina. It consists of an incomplete, partially articulated skull in which some of the bones are preserved in three dimensions. The specimen has a unique character combination that allows us not only to diagnose the genus Notodectes but also confirm that it is a member of the actinopterygian order Pachycormiformes. At present, Notodectes represents the first endemic pachycormiform from the Southern Hemisphere and the first specimen found in Mendoza Province (northwestern region of the Neuquén Basin). Also, Notodectes is the first fast-swimming and clearly ichthyophagous pachycormid reported from the Jurassic of South America.
We provide a complete description of one of the oldest plesiosaurians, Stratesaurus taylori from the earliest Hettangian of the United Kingdom. At least 25 apomorphies distinguish S. taylori from the sympatric Thalassiodracon hawkinsii, to which all three specimens of S. taylori were originally referred. Several features of the skull of S. taylori suggest specialization on small prey items, or sieve feeding. In particular, it has anteriorly inclined premaxillary and mesial maxillary teeth and an only weakly heterodont maxillary dentition. This indicates niche partitioning among sympatric small-bodied plesiosaurians: T. hawkinsii has a pronouncedly heterodont dentition. With a body length estimated around 2 m, S. taylori is one of the smallest plesiosaurians, comparable to T. hawkinsii. Our anatomical review of S. taylori suggests difficulty determining its precise phylogenetic affinities. This is consistent with a general lack of phylogenetic resolution among earliest Jurassic plesiosaurians, which may result from missing data on their Triassic ancestry. However, due to its plesiomorphic morphology and well-characterized anatomy, we recommend S. taylori as an ingroup representative of Plesiosauria for future cladistic analyses of Triassic sauropterygians.
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