A new brontothere from the Eocene of South China

The upper Eocene Youganwo Formation in Maoming Province, Guangdong Province, China, produced abundant remains of turtles and crocodiles, but mammalian remains are rare. The previously found mammals from Youganwo Formation include a nimravid carnivore and an amynodontid perissodactyl. Here we report on a new brontotheriid perissodactyl from the Youganwo Formation. Maobrontops paganus gen. et sp. nov. is described based on a maxillary fragment with P4 and M1–2 (SYSU-M-4). Maobrontops paganus gen. et sp. nov. is characterized by the combination of a simple P4 without a hypocone with derived molars having large molar fossae and large anterolingual cingular cusp. A parsimony implied weighting character analysis places Maobrontops gen. nov. in the clade Embolotheriita as a sister taxon to the terminal subclade containing Nasamplus, Protembolotherium, and Embolotherium. Maobrontops paganus gen. et sp. nov. is one of the largest Asian brontotheres. The brontotheriid fauna of South China is endemic and includes at least three valid taxa: Dianotitan from Brontotheriita and Pygmaetitan and Maobrontops gen. nov. from Embolotheriita

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)

New Records of Proteid Salamanders (Amphibia, Caudata) from the Pliocene of Ukraine and Lower Pleistocene of Moldavia

Two isolated proteid vertebrae are described: the first is from the Pliocene Kotlovina locality, Ukraine, and is referred to Mioproteus sp., whereas the second is from the lower Pleistocene Chishmikioi locality in Moldavia (former USSR) and is referred to “Mioproteus” wezei. This problematic species is distinct from the Miocene M. caucasicus and may pertain to a distinct genus that includes aquatic ancestors for the modern troglobitic Proteus.Описаны два позвонка, отнесенные к Mioproteus sp. и «Mioproteus» wezei и происходящие из соответственно плиоценового местонахождения Котловина в Украине и раннеплейстоценового местонахождения Чишмикиой в Молдавии. Последний вид отличен от миоценового M. caucasicus и, возможно, его следует выделить в особый род, объединяющий речных предков современных пещерных Proteus

A new hypercarnivorous hyaenodont from the Eocene of South China

A new hyaenodont Maocyon peregrinus, gen. et sp. nov., is described based on a partial skull and associated mandible from the upper Eocene Youganwo Formation at Maoming locality in Guangdong Province, China. It shows certain similarities with the Hyainailouroidea in the skull structure, including anteroposteriorly extended jugal/squamosal suture, presence of a preglenoid crest, a lateral expansion of the squamosal posterior to the zygomatic arch, a transversally expanded mastoid process, a nuchal crest that does not extend laterally to mastoid process, and large occipital condyles. The phylogenetic analysis clusters the new taxon with Orienspterodon dahkoensis from the late middle Eocene of China and Myanmar and places this clade within the Hyainailouridae in a polytomy with the Apternodontinae and the Hyainailourinae

The oldest record of Alvarezsauridae (Dinosauria: Theropoda) in the Northern Hemisphere

© 2017, Public Library of Science. All rights reserved. This is an open access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication. Procoelous caudal vertebrae, a carpometacarpus with a hypertrophied metacarpal II, and robust proximal and ungual phalanges of manual digit II of a small theropod dinosaur from the Upper Cretaceous (Turonian) Bissekty Formation at Dzharakuduk, Uzbekistan, show unequivocal synapomorphies of the clade Alvarezsauridae and thus are referred to it. The caudal vertebrae have a unique longitudinal canal within the neural arch. The carpometacarpus, with metacarpal III occupying about one third of the width of the carpometacarpus, shows the most plesiomorphic stage of the evolution of the forelimb among known alvarezsaurids. The proximal phalanx of manual digit II differs from the corresponding bone in Parvicursorinae in having a less asymmetrical proximal articular surface without a dorsal process and short ventral ridges. The ungual phalanx of manual digit II has laterally open ventral foramina. The Bissekty alvarezsaurid possibly represents a basal parvicursorine and is the stratigraphically oldest known alvarezsaurid in Asia known to date

The stem placental mammal Prokennalestes from the Early Cretaceous of Mongolia

© 2017, Pleiades Publishing, Ltd. All materials, including upper and lower jaw fragments and isolated teeth, of two closely related species of the stem placental mammal Prokennalestes, P. minor Kielan-Jaworowska et Dashzeveg, 1989 (258 specimens) and P. trofimovi Kielan-Jaworowska et Dashzeveg, 1989 (251 specimens), from the type locality of Khovoor (Early Cretaceous of Mongolia) are described. These extensive materials allow for the first time the study of morphological and size variability in an Early Cretaceous mammal. Prokennalestes can be diagnosed by the dental formula I?/4, C1/1, P4–5/5, M3/3, presence of the Meckelian groove, the mandibular foramen positioned dorsally on a prominent longitudinal ridge, presence of the masseteric foramen, double-rooted and premolariform lower canine, submolariform P5 with a large protocone and minute metacone, presence of the preparastyle, cusplike postmetacrista, and cusplike conules with incipient conular cristae on the upper molars, premolariform p5, the protoconid distinctly higher than the metaconid, the paraconid and metaconid connate at the base, transverse protocristid, and presence of distal metacristid on the lower molars. Two Prokennalestes species are reliably distinguished by the tooth dimensions (P. minor is smaller by 20%), the position of the infraorbital foramen (under P4 in P. minor and between P4 and P5 or under P5 in P. trofimovi), the presence of protoconal swelling on P4 (usually absent in P. minor and usually present in P. trofimovi), the ectocingulum extension in M3 (longer in P. minor), position of the posterior end of the mandibular symphysis (under p2 in P. minor, under p2–p3 in P. trofimovi), and by the position of the posterior mental foramen (under p4 in P. minor and under p5 in P. trofimovi). Taking into account considerable morphological differences between the two samples, they are regarded as different species rather than sexual morphs of the same species. Prokennalestes is a basal eutherian mammal similar in phylogenetic position to other stem placentals (Eomaia, Murtoilestes, Bobolestes, Aspanlestes). A more exact phylogenetic position of Prokennalestes can be established based on rigorous phylogenetic analysis including a large set of known stem therian and stem placental taxa.