Pleistocene hares from the East Siberian Arctic (Lagomorpha, Leporidae)

Isolated fossil hare bones from seven Pleistocene localities in the east Siberian Arctic are attributed to Lepus tanaiticus vereschagini Averianov, 1995 (Mamontovaya Khayata) and to L. tanaiticus subsp. indet. (other localities)

OSTEOCONDUCTIVE COMPOSITE MATERIALS BASED ON POLY-L-LACTIDE AND NANOCRYSTALLINE CELLULOSE MODIFIED WITH POLY(GLUTAMIC ACID)

The aim of this work was to obtain the series of composite polymeric materials based on poly-L-lactide (PLLA) with different contents of hydrophilic nanocrystalline cellulose (NCC) and modified with poly(glutamic acid) (PGlu) nanocrystalline cellulose (NCC-PGlu) (5, 10 and 15 wt%) as fillers. For this purpose several methods for modifying NCC with poly(glutamic acid) were tested. The best result was demonstrated by the partial oxidation of the NCC and the subsequent interaction of the obtained aldehyde NCC groups with the terminal amino groups of PGlu.The research was carried out with the use of some equipment of the Research Park of St. Petersburg State University: “Interdisciplinary Center for Nanotechnology” and “Center for Chemical Analysis and Materials Research”

Morphology of the petrosal and stapes of Borealestes (Mammaliaformes, Docodonta) from the Middle Jurassic of Skye, Scotland

We describe, in unprecedented detail, the petros-als and stapes of the docodont Borealestes from the Middle Jurassic of Scotland, using high resolution lCT and phase- contrast synchrotron imaging. We describe the inner ear endocast and the vascularized interior structure of the pet-rosal, and provide the first endocranial view of a docodontan petrosal. Our study confirms some similarities in petrosal and stapedial morphology with the better known Haldan-odon of the Late Jurassic of Portugal, including: (1) the degree of curvature of the cochlea; (2) multiple features related to the highly pneumatized paroccipital region; (3) the shape of lateral trough, the fossa of the M. tensor tym-pani, and the ridge on the promontorium; (4) the round shape of the fenestra vestibuli; and (5) overall morphology of the stapes. But Borealestes differs from Haldanodon in having a bony ridge that separates the tympanic opening of the prootic canal, the secondary facial foramen and the hia-tus Fallopii, from the fenestra vestibuli. We identify two new vascular structures: the anterior and posterior trans-cochlear sinuses, which traverse the pars cochlearis around the cochlear nerve (VIII). These trans-cochlear sinuses have not been observed in previous docodont specimens, and could be an autapomorphy of Borealestes, or apomorphic for this clade. We also establish the anatomical relationship of the circum-promontorium plexus to the inner endocast. The high quality of our scans has made these structures visible for the first time

The mandible and dentition of Borealestes serendipitus (Docodonta) from the Middle Jurassic of Skye, Scotland

The Middle Jurassic docodont Borealestes serendipitus was the first Mesozoic mammal found in Scotland over 40 years ago. Its affinities and morphology have remained poorly understood. Although multiple dentary fragments and isolated teeth have been recovered from Scotland and England, they have not yet been described in sufficient detail. We report new, more complete specimens collected during recent field work on Skye, Scotland, combined with previously collected material. This includes upper and lower dentition and an almost complete right dentary. We present an updated description and diagnosis of the genus Borealestes, based on high-resolution micro-computed tomography (micro-CT) and synchrotron scans. We identify seven key features that distinguish Borealestes from other docodonts, including a pronounced a–c crest, absence of the a–g crest on cusp a, an anterior fovea at the buccolingual midpoint of the upper molar, and the convergence of the Meckel’s groove with the ventral margin of the mandible. We also present a revised diagnosis for the second species, B. mussettae. Our phylogenetic analysis supports a clade formed by Borealestes, Haldanodon, Docofossor, and Docodon. Ontogenetic variation in the mandibular morphology of Borealestes is similar to that seen in Docodon and Haldanodon, with the delayed emergence of the ultimate lower molar, the shift of the last molar to the front of the coronoid process, and a posterior shift of the Meckel’s sulcus in successively older individuals. This supports a distinctive growth pattern in the clade including Borealestes and Docodon, one that may be present in Docodonta as a whole

A New Pterosaur (Pterodactyloidea: Azhdarchidae) from the Upper Cretaceous of Morocco

The Kem Kem beds in South Eastern Morocco contain a rich early Upper (or possibly late Lower) Cretaceous vertebrate assemblage. Fragmentary remains, predominantly teeth and jaw tips, represent several kinds of pterosaur although only one species, the ornithocheirid Coloborhynchus moroccensis, has been named. Here, we describe a new azhdarchid pterosaur, Alanqa saharica nov. gen. nov. sp., based on an almost complete well preserved mandibular symphysis from Aferdou N'Chaft. We assign additional fragmentary jaw remains, some of which have been tentatively identified as azhdarchid and pteranodontid, to this new taxon which is distinguished from other azhdarchids by a remarkably straight, elongate, lance-shaped mandibular symphysis that bears a pronounced dorsal eminence near the posterior end of its dorsal (occlusal) surface. Most remains, including the holotype, represent individuals of approximately three to four meters in wingspan, but a fragment of a large cervical vertebra, that probably also belongs to A. saharica, suggests that wingspans of six meters were achieved in this species. The Kem Kem beds have yielded the most diverse pterosaur assemblage yet reported from Africa and provide the first clear evidence for the presence of azhdarchids in Gondwana at the start of the Late Cretaceous. This, the relatively large size achieved by Alanqa, and the additional evidence of variable jaw morphology in azhdarchids provided by this taxon, indicates a longer and more complex history for this clade than previously suspected

Skeleton of an unusual cat-sized marsupial relative (Metatheria: Marsupialiformes) from the middle Eocene (Lutetian: 44-43 million years ago) of Turkey

We describe a near-complete, three-dimensionally preserved skeleton of a metatherian (relative of modern marsupials) from the middle Eocene (Lutetian: 44–43 million years ago) Lülük member of the Uzunçarşıdere Formation, central Turkey. With an estimated body mass of 3–4 kg, about the size of a domestic cat (Felis catus) or spotted quoll (Dasyurus maculatus), it is an order of magnitude larger than the largest fossil metatherians previously known from the Cenozoic of the northern hemisphere. This new taxon is characterised by large, broad third premolars that probably represent adaptations for hard object feeding (durophagy), and its craniodental morphology suggests the capacity to generate high bite forces. Qualitative and quantitative functional analyses of its postcranial skeleton indicate that it was probably scansorial and relatively agile, perhaps broadly similar in locomotor mode to the spotted quoll, but with a greater capacity for climbing and grasping. Bayesian phylogenetic analysis of a total evidence dataset comprising 259 morphological characters and 9kb of DNA sequence data from five nuclear protein-coding genes, using both undated and “tip-and-node dating” approaches, place the new taxon outside the marsupial crown-clade, but within the clade Marsupialiformes. It demonstrates that at least one metatherian lineage evolved to occupy the small-medium, meso- or hypo-carnivore niche in the northern hemisphere during the early Cenozoic, at a time when there were numerous eutherians (placentals and their fossil relatives) filling similar niches. However, the known mammal fauna from Uzunçarşıdere Formation appears highly endemic, and geological evidence suggests that this region of Turkey was an island for at least part of the early Cenozoic, and so the new taxon may have evolved in isolation from potential eutherian competitors. Nevertheless, the new taxon reveals previously unsuspected ecomorphological disparity among northern hemisphere metatherians during the first half of the Cenozoic

Early Cretaceous symmetrodont mammal Gobiotheriodon from Mongolia and the classification of Symmetrodonta

The “symmetrodont” mammal, Gobiotheriodon infinitus (Trofimov, 1980), from the Early Cretaceous (Aptian–Albian) of Mongolia, is redescribed.The species is restricted to the holotype only (dentary with three last molars), the referred maxillary fragment with M3? is considered here as cf. Gobiconodon sp.The dental formula of G. infinitusis reinterpreted as i1–3 c1 p1–3 m1–4. G. infinitus is characterized by a short dentary symphysis; long, well−developed Meckel's groove; small, triangular−shaped pterygoid fossa; weakly developed pterygoid crest; i3 enlarged; p1–3 two−rooted; lower molars acute− to obtuse−angled, labial cingulids lacking, lingual cingulids very short, well developed mesial and distal cingulid cuspules (“e” and “d”) and prominent wear surface on the paracristid. Gobiotheriodon is similar to Tinodon (Late Jurassic, USA; Early Cretaceous, Great Britain and Portugal) in postcanine dental formula and structure of the pterygoid fossa; it is provisionally assigned to Tinodontidae Marsh, 1887.Some taxa previously assigned to (or suggested as possible relatives of) “Symmetrodonta” are reviewed.Amphidontidae Simpson, 1925 is considered as nomen dubium.A new classification for “Symmetrodonta” is proposed

New Late Cretaceous mammals of southern Kazakhstan

Mammalian remains from the lower part of the Darbasa Formation (lower Campanian) at the 'Grey Mesa' locality in the Alymtau Range, southern Kazakhstan, are described. They include ?Bulganbaatar sp. (Multituberculata), Deltatheridium nessovi, sp. n. (Deltatheroida), and four eutherians: an undeterminated ?otlestid kennalestoid (?Otlestidae), ?Alymlestes sp. (Zalambdalestidae), ?Aspanlestes sp. (Zhelestidae), and an undeterminated eutherian. This new Cretaceous fauna is most similar to that from the Djadokhta Formation in Mongolia and may tentatively confirm an early Campanian age for the latter