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Tham Wiman Nakin or “Snake Cave” has so far been recognized as being the only late Middle Pleistocene Homo-bearing fauna, dated to older than 169 ka, in mainland Southeast Asia. Since the last two decades, the highly diversified mammal fauna found from this cave has been widely used as standard references for several studies, though the majority of fossil primates, carnivores, and ungulates have never been described in detail. This paper presents taxonomic descriptions of unpublished fossil specimens from the long-known collection of Tham Wiman Nakin. As a result, the fauna of Tham Wiman Nakin consisted of at least 28 large mammal taxa. Although several previously described specimens are re-assigned to different tooth elements and/or mammal taxa, our taxonomic study confirms the existence of most of the species identified from the previous work and describes three additional taxa for the locality: an Asian badger, a tiger, and a Himalayan goral. The Tham Wiman Nakin fauna is one of the most diverse Pleistocene mammals, including a hominin, in mainland Southeast Asia and documents long-term survivors of living species since the late Middle Pleistocene. Based on several recent dates of fossil sites in mainland Southeast Asia, biochronological data imply a possible faunal age up to the maximum of 300 ka for the Tham Wiman Nakin fauna, but younger than that of Pha Bong where Gigantopithecus was present. Fossil records in the region also suggest a relatively stable fauna through Pleistocene glacial-interglacial cycles, at least from the late Middle to latest Pleistocene. The extinction occurring in the mainland varied across taxa and likely resulted in less impacted biodiversity loss prior to the Holocene, compared to other continents, as indicated by the small proportion of species becoming extinct during each interval. The importance of stable mosaic habitats through time may provide clues to the long-term survival of several large mammal taxa in the region.

International audience; The study and reanalysis of late Oligocene and middle Miocene dental material from Thailand provides evidence for long-distance stratigraphic correlations, and thus sheds new light on past terrestrial connections between Southeastern Asia and Europe. Here we report the oldest occurrence of Ursidae in southern Asia – a late Oligocene fossil from Nong Ya Plong previously referred to Mustelida but reattributed here to Cephalogale aff. geoffroyi (Ursidae, Hemicyoninae, Cephalogalini). We also describe a new Viverridae, Semigenetta cf. steinheimensis, from the middle Miocene carnivoran-rich locality of Mae Moh. The presence of these two taxa in Western Europe reinforces stratigraphic correlations of the MP29 and MN7–8 fossil sites with Southeast Asian localities. Members of the tribe Cephalogalini may have migrated several times from Asia to Europe, or vice-versa, during the Oligocene and early Miocene via either a northern route across northern China, or a southern route traversing southern Asia and the Middle East. Semigenetta could have dispersed along a corridor through Central Asia or a southern Asian route into Thailand during the middle Miocene. Our study thus indicates that medium- or large-sized carnivorans constitute a useful tool for reconstructing the paleobiogeography of extinct species.

The diversity of basal ungulates is significant in the late middle Eocene Pondaung Formation (Myanmar). However, the precise identification or attribution of some fossils is sometimes difficult because of the scarcity and poor preservation of the material. We describe here a new genus and species of a Dichobunidae from Paukkaung Kyitchaung 2 locality, that is morphologically and probably phylo­genetically close to a taxon from the early-middle Eocene of Pakistan, and we discuss the attribution of dental material to Myanmarius chitseini Tsubamoto, Egi, Takai, Htike & Zin-Maung-Maung-Thein, 2013, an inderterminate artiodactyl from Pondaung. This study also confirms that dispersals were possible between the Indian subcontinent and Southeast Asia during the first part of the Eocene.

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We describe several mammal taxa from the poorly known late Eocene locality of Bang Mark, Krabi Basin in southern Thailand. Most of them were unknown in that locality that now includes 19 distinct t...

Since their discovery in 1927, the phylogenetic status of the Myanmar amphipithecines has been highly debated. These fossil primates are recognized either as anthropoids or as adapiform strepsirrhines. This uncertainty was largely the consequence of a limited fossil record consisting mostly of jaw fragments but lacking the critical cranial elements that might resolve this debate. We report here cranial remains associated with an ulna from a single individual pertaining to the amphipithecine Ganlea megacanina . In addition to anthropoid-like dentognathic characters, Ganlea displays several ulna and skull features that testify to its anthropoid affinities (e.g. short subvertically oriented lacrimal duct, lacrimal foramen and bone inside the orbit, maxillary contribution to the lower orbital rim, fused metopic suture). By contrast to crown anthropoids, however, Ganlea lacks postorbital closure, confirming that postorbital closure appeared later than many anthropoid dentognathic characters and evolved convergently in extant tarsiers and anthropoids. Thus, amphipithecines must now be recognized as stem anthropoids offering a unique window on the early evolution of cranial and skeletal features in anthropoids, and reinforcing the hypothesis of an origin and early diversification of anthropoids in Asia.

Two new genera and species of small basal ruminants are described from the middle Eocene Pondaung Formation in Myanmar. One form, Paukkaungmeryx minutus, gen. et sp. nov., is attributed to a primit...

Paleoecological and paleoclimatic records based on the stable isotopes of mammalian tooth enamel are poorly known in mainland Southeast Asia during the Pleistocene. Khok Sung in Northeastern Thailand is a late Middle Pleistocene terrace deposit, tentatively dated either as 213 ka or 188 ka, yielding 15 described mammalian taxa with especially abundant and complete fossil remains. To investigate paleodiets and habitats of these ancient mammals and to understand the corresponding regional climate, we performed an analysis of stable carbon and oxygen isotopes extracted from tooth enamel carbonate of various mammalian taxa, coupled with the cenogram method. The enamel δ13C values of Khok Sung mammals indicate a variety of diets, ranging from pure C3 to C4 plants, suggesting that C4 grasses were a major component of local Thai ecosystems during the late Middle Pleistocene. The stable isotopic distinction between C3 and C4 plants suggests that the Pleistocene wildlife habitats ranged from closed forests to open grasslands for the Khok Sung area. Moreover, differences within sympatric Pleistocene herbivores such as proboscideans, rhinoceroses, and cervids characterize possible niche partitioning by minimizing interspecific overlap. Paleoclimatic interpretations based on the intra-tooth variability in enamel δ18O values from large mammals and on the cenogram analysis reflect significant seasonal variations in precipitation and temperature, and humid conditions, for the Khok Sung locality. Compared to modern environments in Thailand, it is apparent that C4-dominated grasslands were more widespread at that time when anthropic impacts on the ecosystems were presumably absent or minimal.

RésuméL’évolution de l’homme s’inscrit dans la durée, comme celle de la plupart des autres mammifères. Les premiers primates anthropoïdes, les plus anciens représentants de sa lignée, proviennent d’Asie et remontent à 45 millions d’années. Au cours de cette longue évolution, deux stades se sont révélés très importants : leurs débuts et l’émergence des hominidés, autour de 7 millions d’années. Ces deux périodes critiques sont évoquées ici, avec de nouvelles preuves de l’origine asiatique de notre rameau, puis sa dispersion vers l’Afrique, entre 45 et 40 millions d’années, qui a conduit à l’émergence précoce des premiers hominidés, représentés par trois formes distinctes, dont Toumaï, qui apparaît comme le plus ancien et le plus engagé en direction de la lignée humaine.AbstractThe human lineage has a very ancient origin, as most of the mammals. Its oldest representatives, anthropoid primates, have been described from Asia some 45 million years ago. During this long evolutionary story, two critical stages have appeared as especially important, their beginning in Asia and the emergence of hominids in Africa, some seven million years ago. These two stages are discussed hereby with new data relative to their Asian origins and their dispersal into Africa between 45 and 40 million years ago. Following this dispersal event, these primates evolved in Africa and gave rise to the early hominids. These appeared around seven million years ago and have three distinct representatives. Among them, Toumaï appears as the oldest and the closest to our ancestry, a point that is evidenced here.

International audience; The evolutionary history of Asian Miocene hominids (great apes and humans) remains poorly documented, obscuring the ancestry of orangutan (Pongo). Khoratpithecus from the middle and late Miocene of Thailand and Myanmar was previously documented only by mandibles and isolated teeth. It has been interpreted as the closest relative of Pongo based on shared derived mandible characters such as symphyseal morphology and the lack of anterior digastric muscle scars. Here we describe a new maxilla, MFT-K176, which originates from the same sedimentary unit as the holotype mandible of Khoratpithecus piriyai from the late Miocene in Nakhon Ratchasima province, Northeastern Thailand. The new maxilla displays a unique subnasal morphology with several derived characters being shared only with Sivapithecus and Pongo, confirming its attribution to the pongine clade. However, it differs from other known Asian hominids by it subnasal and dental morphology, showing more similar to Khoratpithecus chiangmuanensis teeth. Metric similarities with the mandible of K. piriyai corroborate the referral of MFT-K176 to Khoratpithecus. However, as associated upper and lower teeth would be required to evaluate the latter assertion more conclusively, we attribute it provisionally to cf. Khoratpithecus sp. Other anatomical characters from the clivus, the palate and the molars are peculiar for this hominid but do not exclude it from a sister group relationship with Pongo. This new maxilla plays a pivotal role in understanding that Ankarapithecus occupies a more basal position within the pongine clade and supports the exclusion of Lufengpithecus from this clade.

International audience; We describe two entelodontid upper premolars that were recovered from the late Eocene of the Krabi coal mine in southern Thailand. The size and morphology of the material suggest that it can be referred to Entelodon aff. E. gobiensis, a species known from the late Eocene to the early Oligocene of northern Asia and southern China. The Thai material documents for the first time the southernmost occurrence of entelodontids in Asia during the Paleogene and also suggests that Eocene Southeast Asian mammal localities might potentially yield further entelodontid remains mostly associated with selenodont ungulates.; Nous décrivons deux prémolaires supérieures d’entelodontidé découvertes dans la mine de lignite d’âge Éocène supérieur de Krabi, en Thaïlande méridionale. Les dimensions et la morphologie de ce matériel suggèrent qu’il peut être rapporté à Entelodon aff. E. gobiensis, une espèce connue de l’Éocène supérieur à l’Oligocène inférieur d’Asie septentrionale et du Sud de la Chine. Ces restes fossiles de Thaïlande documentent, pour la première fois, l’existence la plus méridionale d’entelodontidés en Asie durant le Paléogène et suggèrent que les localités à mammifères fossiles éocènes d’Asie du Sud-Est pourraient potentiellement livrer d’autres restes d’entelodontidés associés principalement à ceux d’ongulés sélénodontes.

We report here the first direct dating study of the faunal assemblage from Khok Sung locality, Thailand. This palaeontological site is of great biochronological, palaeoenvironmental and biogeographical significance. Firstly, it has yielded a rich and diversified Pleistocene vertebrate fauna with up to 15 mammalian species from 13 genera, 10 reptile species, as well as fish and bird remains. Interestingly, while most of the mainland Southeast Asian Pleistocene mammal fossils originate from cave deposits, the Khok Sung fossil layer is located within an 8 m thick fluvial terrace. Secondly, it is geographically located in an area of major importance for reconstructing the migration pathway of large mammals between South China and Java. Combined US-ESR dating of five teeth provides two possible ages of 130 ± 29 ka and 217 ± 36 ka for the fossils. The reason for the occurrence of these two age groups lies in the fact that it was not possible to obtain sediments that were directly associated with the measured samples, nor was it possible to carry out in situ gamma dose rate measurements due to the high water level. Sediment samples recovered from museum specimens show significantly variable concentrations of radioelements. Both options are equally plausible, as independent methods did not provide firm evidence favouring one or the other age range. The results illustrate the intrinsic limitations of the ESR dating method when fossil teeth are not collected in situ during the excavation. Regardless whether the age of the Khok Sung fauna corresponds to MIS 7 or early MIS5, it is nevertheless one of the oldest assemblages directly dated in the region. Further efforts are required for more accurate fossil identification and attribution and for additional numerical dating in this region to improve the biochronological framework of the Pleistocene mammalian faunas in Southeast Asia, which presently remains quite imprecise.

International audience; Parapithecines are an extinct subfamily of stem anthropoid primates previously known only from the Jebel Qatrani Formation in Egypt. Here, we describe isolated teeth pertaining to Simonsius harujensis sp. nov., a relatively small-bodied parapithecine from strata near Zallah Oasis in the Sirt Basin of central Libya that is estimated to date to ∼31 Ma on the basis of mammalian biostratigraphy. The dental morphology of S. harujensis sp. nov. is generally intermediate between that of the closely related parapithecines Parapithecus fraasi and Simonsius grangeri, highlighting some of the anatomical features distinguishing the latter taxa and providing further support for their generic separation. A phylogenetic analysis using parsimony methods was performed on a character-taxon matrix incorporating data from the new Libyan parapithecine, virtually all other parapithecids and the proteopithecid Proteopithecus sylviae. Results of this analysis suggest that parapithecids comprise a basal clade consisting of three species of Biretia and a more derived clade including Parapithecinae (Parapithecus and Simonsius) and Qatraniinae (Qatrania, Ucayalipithecus, and Apidium). Body mass estimates for parapithecids were calculated on the basis of regression equations generated to predict body mass from the occlusal area of upper and lower cheek teeth in extant anthropoids. The relatively small body mass of S. harujensis sp. nov. and its reconstructed phylogenetic position as the sister group of S. grangeri, which is the largest known parapithecid, support the convergent acquisition of body mass larger than 500 g among multiple clades of early Oligocene African anthropoids. The new Libyan parapithecine augments previously reported evidence supporting a substantial degree of faunal provincialism across northern Africa/Arabia during the early Oligocene.

Carnivoraformes is a clade comprised of members of the Carnivora, as well as the paraphyletic assemblage of stem taxa previously united under the “Miacidae”. Here we describe the earliest known African occurrence of a carnivoraform from the early Oligocene Zallah Incision locality in the Sirt Basin of central Libya. The new taxon is represented by three teeth (m1, P4, and dP3), all of which are carnassial loci diagnostic of the Carnivoraformes. Despite its meager anatomical representation, the new Libyan carnivoraform possesses numerous characters that distinguish it from contemporaneous African hyaenodonts, including the retention of a large m1 metaconid, an enlarged and transversely oriented P4 metastyle, and the absence of a metacone on dP3, among other features. The generally primitive nature of known tooth loci and the absence of clear synapomorphies with crown carnivorans suggest that the new carnivoraform may be a relatively basal member of the clade. If so, the new Libyan taxon would be the only known African occurrence of a basal carnivoraform.

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International audience; The late middle Miocene fossil-bearing lignite zones of the Mae Moh Basin, northern Thailand, have yielded a rich vertebrate fauna, including two species of Carnivora described thus far: the bunodont otter Siamogale thailandica (known from over a 100 specimens) and the large amphicyonid Maemohcyon potisati. Here we describe additional carnivoran material from Mae Moh comprising new remains of Maemohcyon potisati as well as remains of seven new carnivorans belonging to at least four families: a new species of Siamogale (S. bounosa), a new species of another otter (Vishnuonyx maemohensis), one representative of the genus Pseudarctos (a small amphicyonid), a new genus of Asian palm civet, Siamictis, one representative of another civet (cf. Viverra sp.), a new species of mongoose (Leptoplesictis peignei) and a Feliformia indet. This carnivoran assemblage constitutes one of the richest for the middle Miocene of eastern Asia and by far the richest for the Neogene of Southeast Asia. While the presence of new species indicates a certain degree of endemism for the Mae Moh Basin, paleobiogeographic cluster analyses conducted on carnivoran faunas from the middle and late Miocene of Asia indicates that a southern Asian biogeographic province, analogous to the current Oriental Realm, has existed since at least the middle Miocene. These results strengthen the observation that the Himalayan Mountains and Tibetan Plateau constitute significant physical barriers as well as an important climatic barrier (through the strengthening of monsoon systems) preventing north-south mammal dispersals in Asia since at least the middle Miocene.

The Galericinae are a group of Erinaceidae that are currently distributed in Southeast and Eastern Asia. Although galericines have an Asian origin, their fossil record in this region is scarce, whi...

International audience; The middle Eocene Pondaung Formation in Myanmar has yielded a rich mammalian fauna including several Primate taxa. Hyaenodonta are known by the genera Kyawdawia, Yarshea, Orienspterodon, and two other indeterminate taxa. We describe here new material of Kyawdawia, including some morphological details, a new species of the hypercarnivorous genus Propterodon and an indeterminate species, different from those described earlier in Myanmar, and characterized by a reduction of m3 and would belong to a third lineage with the same evolutionary trend as Galecyon and the Limnocyoninae. The hyainailourines (Orienspterodon) and hyaenodontines (Propterodon) are recorded for the first time in Southeast Asia and these subfamilies appeared in quasi the same time in Europe illustrating probably a profound change in the carnivorous fauna among Laurasia.; La formation de l’Éocène moyen de Pondaung, en Myanmar, a livré une riche faune mammalienne, dans laquelle on a signalé plusieurs taxons de Primates. Parmi les autres ordres de mammifères, celui des Hyaenodonta était connu jusqu’à présent par les genres Kyawdawia, Yarshea, Orienspterodon et deux autres taxons indéterminés. Nous décrivons dans cet article du nouveau matériel de Kyawdawia, qui apporte des précisions sur certains détails morphologiques, une nouvelle espèce du genre hypercarnivore Propterodon ainsi qu’une forme indéterminée, qui diffère de toutes les espèces décrites à ce jour en Birmanie. Elle se caractérise, en particulier, par la réduction de m3, et peut représenter une troisième lignée montrant la même tendance évolutive que les Limnocyoninae et Galecyon. Les hyainailourinés (Orienspterodon) et les hyaenodontinés (Propterodon) sont les plus anciens connus dans le Sud-Est asiatique. Ces sous-familles apparaissent quasiment à la même époque en Europe, et la fin de l’Éocène moyen pourrait correspondre à un changement majeur de la faune de carnassiers en Eurasie.

A well-preserved astragalus of the anomaluroid rodent Pondaungimys anomaluropsis is described from the late middle Eocene Pondaung Formation of central Myanmar. This specimen is the first postcrani...

The locality of Khok Sung, Nakhon Ratchasima province, which corresponds to an ancient river terrace, has yielded the richest Pleistocene fauna of Thailand with a thousand of fossil vertebrate remains. This fauna has been previously dated between the Early Pleistocene and the Middle Pleistocene. We describe here a nearly complete hyaenid skull and associated mandible identified as belonging to spotted hyaena Crocuta crocuta ultima. The spotted hyaena C. c. ultima, which extended its maximum latitudinal distribution from northern China to Peninsular Thailand, is a characteristic component of Southeast Asian Middle Pleistocene faunas. These new biochronological data, coupled with a magnetostratigraphic study of the lithological section, provide a powerful multiproxy approach for the dating of Khok Sung fauna, pinpointing rather a late Middle Pleistocene age than the Early Pleistocene. In addition, the occurrence in the Khok Sung section of a short reverse excursion of the magnetic field within the Brunhes normal Chron can be tentatively identified as corresponding either to the “Iceland Basin” (188 ka) or to the “Pringle Falls” (213 ka) excursion, suggesting an even more precise dating of the locality. According to the presence of a spotted hyaena, the Khok Sung fauna may illustrate an open canopy habitat in a floodplain with abundant and diversified herbivores, close to the main river channel. This interpretation contrasts with the paleobotanical data which indicate wet and dry tropical forests and may instead describe the surrounding upland vegetation.

We report the discovery of a new early Oligocene vertebrate fauna from the vicinity of Zallah Oasis in the Sirt Basin of central Libya. The Zallah Incision local fauna has been recovered from the base of a fluvial channel within a rock unit that has been mapped as “Continental and Transitional Marine Deposits.” This rock unit has produced fossil vertebrates sporadically since the 1960s, but the Zallah Incision local fauna is the most diverse assemblage of fossil mammals currently known from this unit. In addition to lower vertebrates, the fauna includes an indeterminate sirenian, the anthracothere Bothriogenys, a new species of the hyracoid genus Thyrohyrax, new species of the hystricognathous rodent genera Metaphiomys and Neophiomys, Metaphiomys schaubi, and a new species of the parapithecid primate genus Apidium. The Zallah Incision local fauna from Libya appears to be close in age to Fayum quarries V and G in the Jebel Qatrani Formation of Egypt and the Taqah locality in the Ashawq Formation of Oman. Considered together, these early Oligocene faunas support a modest level of faunal provincialism across the northern part of Afro-Arabia during the early Oligocene.

Determining the diet of fossil apes is essential to understand primate evolution. The giant form from Southeast Asia, Gigantopithecus blacki, may have been up to 270 kg and survived until about 100,000 years ago. It is known only from isolated teeth and a few lower jaws with reduced front teeth and enlarged molars and premolars. A large spectrum of diets has been suggested for Gigantopithecus, ranging from carnivorous or grass-feeding in open savannah to a vegetarian diet dominated by fruits or bamboo. To determine its habitat and to understand why it became extinct, we tried to evaluate its dietary niche. The carbon stable isotopic composition of tooth enamel of this taxon compared to coeval and extant mammals from Southeastern Asia show that Gigantopithecus was a forest-dweller with a generalist vegetarian diet and was not specialized on bamboos. In southern China, Gigantopithecus lived in a forested environment, as did the coeval fauna, while in Thailand, it occupied only the forested part of a mosaic landscape including significant parts of open savannah. The carbon isotopic compositions of Gigantopithecus were different from those of omnivorous and carnivorous taxa, but very similar to those of orang-utans and unlike those of the bamboo-specialist giant panda. Therefore, even when open savannah environments were present in the landscape, Gigantopithecus foraging was limited to forested habitats. The very large size of Gigantopithecus, combined with a relatively restricted dietary niche, may explain its demise during the drastic forest reduction that characterized the glacial periods in South East Asia.

The Early Eocene deposits of El Kohol, Algeria, have yielded numerous remains of Numidotherium koholense , one of the most primitive and oldest known proboscideans in Africa. The Upper Eocene proboscideans of the Fayum locality (Egypt), Barytherium sp. and Moeritherium sp., were recently interpreted as aquatic or semi-aquatic, according to the stable isotopic compositions ( δ 13 C and δ 18 O) of their tooth enamel. These data led us to reinvestigate the adaptations of N. koholense . Stable isotopic analysis and observations of histological sections of its long bones reveal that it was essentially terrestrial. According to its position within the phylogenetic tree of Eocene proboscideans, the adaptation to semi-aquatic life appears to have evolved independently in different lineages of Middle and Upper Eocene proboscideans during their adaptive radiation in Africa. Moreover, these new results reopen the debate about the hypothesis that Eocene to Recent proboscideans are derived from semi-aquatic ancestors.

Strain resulting from the collision of India with Asia has caused fundamental changes to Asian drainage patterns, but the timing and nature of these changes are poorly understood. One frequently proposed hypothesis involves the connection of the palaeo Tsangpo drainage to a precursor to the Irrawaddy River of central Myanmar in the Palaeogene. To test this hypothesis, we studied the provenance of Palaeogene fluvio-clastic sedimentary rocks that crop out in central Myanmar, namely the Late Middle Eocene–Early Oligocene Pondaung and Yaw Formations. Isotopic analysis on bulk-rock and petrographic data indicate a primary magmatic arc source, and a secondary source composed of recycled, metamorphosed basement material. Although the exact location of both sources is hardly distinguishable because Burmese and Tibetan provinces share common lithological features, the presence of low-grade metamorphic fragments, the heterogeneity in Sr–Nd isotopic values of bulk sediments and westward-directed palaeoflow orientations indicate a proximal source area located on the eastern Asian margin. Central Myanmar was the locus of westward-prograding deltas opening into the Indian Ocean, supplied by the unroofing of an Andean-type cordillera that extended along the Burmese margin. We found no evidence to support a palaeo Tsangpo–Irrawaddy River, at least during the Late Eocene. Supplementary material: Data locations, and isotopic and petrographic results are available at www.geolsoc.org.uk/SUP18655.

The extinct Southeast Asian primate family Amphipithecidae is regularly cited in discussions of anthropoid origins, but its phylogenetic position remains controversial. In part, the lack of consensus regarding amphipithecid relationships can be attributed to uncertainty regarding the homology of upper molar structures in this group. Here, we describe a virtually pristine upper molar of Pondaungia cotteri from the late middle Eocene Pondaung Formation of Myanmar, which is the first example of a relatively unworn and well-preserved amphipithecid upper molar ever recovered. The distolingual upper molar cusp in this new specimen of Pondaungia appears to be a lingually displaced and enlarged metaconule, rather than a hypocone or pseudohypocone as previous workers have thought. Reassessment of the upper molar morphology of other amphipithecids and putative amphipithecids reveals a very similar pattern in Siamopithecus, Myanmarpithecus and Ganlea, all of which are interpreted as having upper molars showing many of the same derived features apparent in Pondaungia. In contrast, the upper molar morphology of Bugtipithecus diverges radically from that of undoubted amphipithecids, and the latter taxon is excluded from Amphipithecidae on this basis. Phylogenetic analyses of several character–taxon matrices culled from the recent literature and updated to reflect the new information on amphipithecid upper molar morphology yield similar results. Consensus tree topologies derived from these analyses support amphipithecid monophyly and stable relationships within Amphipithecidae. Amphipithecids appear to be stem members of the anthropoid clade.

We describe an exceptionally well preserved skull of a small anthracothere from the late middle Eocene of the Pondaung Formation that can be confidently attributed to Siamotherium pondaungensis, a species that was first diagnosed on the basis of a fragmentary maxilla preserving two upper molars. The new material confirms that Siamotherium pondaungensis is an anthracothere and not a helohyid as repeatedly suggested. According to its dentition and skull structure, Siamotherium pondaungensis was most likely a terrestrial, open-forest animal with an omnivorous diet that showed no significant adaptation to folivory. A phylogenetic analysis that includes both species of Siamotherium confirms their basal position within the Hippopotamoidea.SUPPLEMENTAL DATA—Supplemental materials are available for this article for free at www.tandfonline.com/UJVPCitation for this article: Soe, Aung Naing, O. Chavasseau, Y. Chaimanee, Chit Sein, J.-J. Jaeger, X. Valentin, and S. Ducrocq. 2017. New remains of Siamotherium ...

A fragmentary maxilla referred to a new diacodexeid artiodactyl, Magwetherium burmense, n. gen. and sp., is described from Sabapondaung locality in the middle Eocene Pondaung Formation in Myanmar. Comparisons with other basal artiodactyls known in the Eocene of Asia, Europe, and North America reveal that this unexpected new taxon displays an unusual combination of derived and primitive features. Magwetherium further displays more morphological affinities with the diacodexeid Jiangsudon from the middle Eocene Shanghuang fissure fillings in eastern China than with any other Holarctic dichobunoids. This study also suggests that fossil remains from Pondaung recently described as indeterminate artiodactyls can likely be referred to dichobunids. The occurrence of a diacodexeid artiodactyl in Southeast Asia extends the fossil record of the family in this part of the continent, it represents the youngest representative of the family, and it further documents the adaptive radiation of diacodexeids in Asia during the Eocene.

The fluviatile terrace deposits of Khok Sung, Nakhon Ratchasima province, have yielded more than one thousand fossils, making this the richest Pleistocene vertebrate fauna of Thailand. The excellent preservation of the specimens allows precise characterization of the faunal composition. The mammalian fauna consists of fifteen species in thirteen genera, including a primate, a canid, a hyaenid, proboscideans, rhinoceroses, a suid, cervids, and bovids. Most species correspond to living taxa but globally (Stegodon cf. orientalis) and locally (Crocuta crocuta ultima, Rhinoceros unicornis, Sus barbatus, and Axis axis) extinct taxa were also present. The identification of Axis axis in Khok Sung, a chital currently restricted to the Indian Subcontinent, represents the first record of the species in Southeast Asia. Three reptilian taxa: Crocodylus cf. siamensis, Python sp., and Varanus sp., are also identified. Faunal correlations with other Southeast Asian sites suggest a late Middle to early Late Pleistocene age for the Khok Sung assemblage. However, the Khok Sung mammalian fauna is most similar to that of Thum Wiman Nakin, dated to older than 169 ka. The Khok Sung large mammal assemblage mostly comprises mainland Southeast Asian taxa that migrated to Java during the latest Middle Pleistocene, supporting the hypothesis that Thailand was a biogeographic pathway for the Sino-Malayan migration event from South China to Java.

Two new primitive macroscelideans, Eotmantsoius perseverans gen. et sp. nov. and Nementchatherium rathbuni sp. nov. from the late Middle or Late Eocene locality of Dur At-Talah, Libya, are described. Eotmantsoius is known from a single tooth and is characterized by low crown height, isolated conules, and lack of a preprotocrista and prehypocrista. Based on these characters, it appears to be more plesiomorphic than Chambius (late Early Eocene, Chambi, Tunisia), which was, to date, universally accepted as the oldest and most basal macroscelidean. Eotmantsoius appears, however, somewhat derived in having an entostyle, a pericone, a shorter mesial cingulum and larger intercusp valleys. The phylogenetic position of Eotmantsoius is unclear. The second new species, N. rathbuni, allows a reassessment of Nementchatherium. We suggest that it is the most derived of the herodotiines in having long preprotocrista and prehypocrista, reduced M2/m2, a robust entostyle twinned with the hypocone on M1 and the posterior aspect of the root of the maxillary jugal process placed along the length of M2. Nementchatherium rathbuni appears more derived than N. senarhense, from the Eocene locality of Bir El Ater, Algeria, in having smaller m2-3 with no paraconid, a smaller hypoconulid on m2 and a more reduced talonid on m3 (with smaller hypoconid and entoconid). Nementchatherium rathbuni also has, distal to the m3, a coronoid canal. This character has commonly been proposed as a synapomorphy for paenungulates (e.g. proboscideans, sirenians and hyracoids); we investigate the possibility that it unites macroscelideans and paenungulates, as the superordinal clade Afrotheria suggests. Comparisons reveal that a coronoid canal also occurs in several nonafrotherian orders (lagomorphs, xenarthrans, artiodactyls and perissodactyls), suggesting that is not an exclusive synapomorphy for paenungulates plus macroscelideans. Moreover, the homology of the character within paenungulates is doubtful.

Despite numerous discoveries that have considerably enriched the African-Arabian Tertiary fossil record over the last decades, our knowledge of the evolutionary history of many continental African vertebrate groups during the Paleogene period remains inadequate, particularly when it is compared with the fossil records of Europe or North America. The Eocene Epoch in Africa is especially poorly documented, being restricted to few fossiliferous localities. Our understanding of the early Tertiary emergence, diversification, and paleobiogeographic history of African-Arabian mammals has been further hindered by the lack of a precise temporal framework for these sites. We conducted magnetostratigraphic analyses, associated with biostratigraphic studies, in the fossiliferous sequences exposed in the northwestern Hammadas of the Saharan Platform in the Glib Zegdou area and in the Saharan Atlas at the El Kohol locality (Algeria) to further define the age of these Eocene continental deposits. Based on biostratigraphic constraints, the six polarity zones identified in the El Kohol section can be correlated with chrons C24n to C22r, providing the first direct age estimates for the El Kohol fossiliferous strata between 52 and 51 Ma. Correlation to the geomagnetic polarity time scale, using previously published biostratigraphic data for the Glib Zegdou fauna, suggests an age ranging between 49 and 45 Ma for this section. The high-resolution magnetostratigraphic study of the poorly known continental Eocene Epoch of Algeria provides new insights into the early Tertiary stratigraphy of northwest Africa. The placement of the Algerian localities into a consistent chronological framework constitutes considerable advancement to achieve biostratigraphic correlation of the Paleogene African-Arabian mammal localities.

We report here additional remains referred to Egatochoerus jaegeri from the late Eocene locality of Ban Mark in the Krabi basin, Thailand. The new material described, comprising upper and lower cheek teeth, deciduous premolars and partial cranial remains, makes E. jaegeri the best-documented Eocene representative of Old World Suoidea at present. Detailed study and comparison of their cheek teeth structure reveal a homogeneity of the molar crest and groove patterns of Old World and New World Palaeogene suoids.

In this paper, we describe four fossil rodent taxa from two new localities situated in the Idam Unit ('Bioturbated Unit) of the Dur At-Talah escarpment in central Libya These rodents belong to the family Phiomyidae (Hys tricognathi) and are distributed amongst three genera (Phiomys, Protophiomys, and Talahphiomys gen. nov.) that include three new species (Phiomys hammudai sp. nov., Protophiomys durattalahensis sp. nov., and Talahphiomys libycus sp. nov.). Although some of these new species are inorphologically close to certain phiomyids from the latest Eocene and Oligocene of the Jebel elQatrani Formation of the Fayum in Egypt, the Idam rodent faunas lack the abundant and somewhat morphologically derived Fayum phiomyids (such as: Metaphiomys, Gaudearnus, Paraphiornys, Phiocricetomys), thereby excluding a similar age for the Dur At-Talah rodent assem blages. More resemblance is shared with the phiomyid (Protophiomys algeriensis) of the Nementcha locality in Algeria, for which a late middle Eocene age is presently admitted. Protophiomys is a primitive representative of the phiomyid African radiation and it is represented at Dur At-Talah by a slightly more derived species (Pr. durattalahensis) than that of Nementcha, thereby suggesting a younger age for Dur AtTalah. As a result, the new rodent assemblages suggest a late middle Eocene age for the Idam ('Bioturhated) deposits of the Dur At-Talah escarpment. This age hypothesis is substantiated by other mammals (especially Proboscidea), which occur in the same sedimentological unit. Interestingly, the dental pattern of Protophiornys and that of Talahphzomys have somewhat stronger affinities with South Asian hystricognath baluchimyines than with Fayum phiomyids. It is clear that haluchimyines and phiomyids have a common ancestry, and that dispersal occurred between Asia and Africa during the middle of the Palaeogene. However, it is not clear if both groups can be strictly separated in two distinct natural groups inasmuch as some haluchimyines (e.g Lophthaluchia, Bugtirnys, Hodsahibia) appear to be phioinyid4ike, and some early members of phiomyids (e.g. Protophiomys, Talahphiomys) are baluchimyine4ike. South Asia and North Africa represent two centres of adaptive radiation of early hystricognathous rodents. The strong dental resemblances between early Asian and African forms are perhaps the result of subsequent convergent evolution after an initial dispersal from Asia, Otherwise, the systematics of these rodents has to be entirely revised, or we must consider that their historical biogeography is much more complex. (C) 2010 The Linnean Society of London, Zoological Journal of the Linnean Society, 2010, 160, 195-213.

Here we describe the first record of a chalicothere from the Miocene of Myanmar. The chalicothere, documented by a partial mandible, was unearthed from the lower portion of the Irrawaddy Formation in the region of Magway, Central Myanmar. The Burmese material belongs to an early late Miocene fauna which recently yielded hominoid remains attributed to Khoratpithecus. The specimen, which is attributed to a chalicotheriine, does not reliably match with any described Miocene Eurasian species of this subfamily, suggesting the possibility it belongs to a new taxon. The discovery of a chalicotheriine in the surroundings of Magway contributes to the hypothesis that closed habitats were an important component of the paleoenvironment of Khoratpithecus.

The variability of one of the oldest known proboscideans, Numidotherium koholense from the Lower Eocene of El Kohol, Algeria, is here examined. The biometrical study of the jugal teeth shows that the population is homogeneous and corresponds to a single species. The important variations of the skull's shape are interpreted as resulting from sexual dimorphism. The dental variability is analysed and discussed from an evolutionary perspective regarding the adaptative radiation of the proboscidean order at the beginning of the Tertiary.

Some elasmobranch teeth, belonging to the batoid genera Dnsyatis and Ouleclia, have been collected for the first time in three late middle Eocene localities of the Pondaung Formation from Central Myanrnar, which are known for their abundant continental vertebrate remains. Considering the environmental conditions, the occurrences of these elasmobranch teeth are indicative of the proximity of the sea shore andlor deltaic systems, which would have allowed to these rays to enter fresh waters.

Recent survey of the fossiliferous variegated mudstones of the PK1 locality (Sabapondaung) in the late middle Eocene Pondaung Formation (central Myanmar) has led to the recovery of a partial right innominate of a relatively large-bodied primate. Given its size and provenance, this bone probably belongs to the same individual represented by the NMMP 20 primate partial skeleton described previously from the same locality. The new fossil, which preserves the region around the acetabulum and the adjacent part of the ilium, clearly exhibits strepsirrhine rather than anthropoid affinities. This addition to our knowledge of the NMMP 20 partial skeleton allows us to reassess the different locomotor interpretations that have been proposed for this specimen. Aspects of pelvic morphology suggest that the NMMP 20 partial skeleton documents a primate that probably engaged in active arboreal quadrupedalism similar to that practiced by medium-sized Malagasy lemurids rather than lorislike slow moving and climbing. Given the conflicting phylogenetic signals provided by NMMP 39 (a talus showing anthropoid affinities) and NMMP 20 (a partial skeleton bearing adapiform affinities), it appears that two higher-level taxonomic groups of relatively large-bodied primates are documented in the Pondaung Formation. The recent discovery of two taxa of sivaladapid adapiforms from the Pondaung Formation indicates that the assumption that the NMMP 20 partial skeleton belongs to an amphipithecid can no longer be sustained. Instead, this specimen apparently documents a third large-bodied sivaladapid species in the Pondaung Formation.

International audience; A new species of Apidium is the most common primate currently known from a newly discovered site near Zallah Oasis in the Sirt Basin of central Libya. Based on current knowledge of the associated fauna, this new species of Apidium is early Oligocene in age, being roughly contemporaneous with faunas from Quarries G and V in the upper part of the Jebel Qatrani Formation in Egypt that also contain species of Apidium. A phylogenetic analysis based on dental characters indicates that the new species of Apidium from Libya is the sister group of Apidium phiomense. Apidium bowni and Apidium moustafai from the Jebel Qatrani Formation in the Fayum are similar in age to the new species of Apidium from Libya, but both of these Egyptian species are more distantly related to A. phiomense from younger stratigraphic levels in the Fayum. This phylogenetic pattern underscores the benefit of enhanced geographic sampling of the fossil record, even in cases where local records are thought to be reasonably comprehensive and well documented. Oligocene parapithecids can be partitioned into two clades corresponding to the subfamilies Parapithecinae (containing Parapithecus and Simonsius) and Qatraniinae (including Qatrania and Apidium). Climatic deterioration during the early Oligocene may have impacted the macroevolutionary dynamics of early Afro-Arabian anthropoids by fostering the fragmentation of forest habitats, thereby promoting allopatric speciation among widespread populations of Apidium and other arboreal taxa.

International audience; Seggeurius is the basal-most hyracoid known to date, and one of the earliest known fossil afrotherians. This taxon has a dramatic importance in mammalian phylogeny, but until now it was known from dental remains only. Here we describe previously unpublished material of Seggeurius, including some mandibular and maxillary fragments, and a braincase. This study is the first to thoroughly describe and discuss the morphology of the ear region and osseous inner ear of a Paleogene hyracoid. It allows a reappraisal of some important characters that are often used in cladistic analyses of Paenungulata. In particular, it seems that in stem hyracoids the orbit is located caudally, the eustachian sac is absent or reduced, the course of the internal carotid artery is intrabullar and medial, and a deep epitympanic sinus, a basisphenoid contribution to the bulla, and the stapedial artery are present. The cochlear canal is rather flattened, and the secondary common crus was rapidly lost. A cladistic analysis of stem placental mammals highlights three derived traits shared by Seggeurius and stem sirenians (the tuber-shaped postglenoid process, the squared and massive mastoid apophysis of the petrosal, and the presence of a swelling on the septum metacochleare) and supports molecular analysis that hypothesizes a Hyracoidea-Sirenia sister-group relationship. This study demonstrates how useful the petrosal and labyrinthine characters of fossils can be for mammalian phylogenetic inference.

International audience; Pliopithecoids represent a monophyletic group of putative stem catarrhines whose evolutionary history is incompletely known. They have been recorded from Europe and Asia, between the late Early Miocene and the Late Miocene. Asian pliopithecoids are less well documented than their European counterparts, often being represented by a fragmentary fossil record. New discoveries are therefore critical to reconstruct the evolutionary history of the whole group. Here, we describe two isolated molars from Ban San Klang, a late Middle Miocene locality in northern Thailand, which confirms the presence of pliopithecoids in Southeast Asia. The lower molar had originally been described as being that of a dendropithecoid, but it was later recognized as pertaining to a pliopithecoid. The discovery, in the same locality, of an additional upper molar attributed to the same species confirms the pliopithecoid status of this taxon and highlights its distinctiveness with respect to other known Asian pliopithecoids. However, the mosaic of primitive and autapomorphic features characterizing this Thai fossil, as well as its limited anatomical representation, preclude us from assigning it to either of the known pliopithecid subfamilies. Nevertheless, it represents the only pliopithecoid in Southeast Asia and displays a mosaic of unique characters which emphasizes the peculiarity of that province, as suggested previously with respect to its hominoid primate.

The late middle Eocene Pondaung Formation, Myanmar, has yielded a diversified assemblage of silicified wood including some of the earliest recorded Dipterocarpaceae. However, mid-Palaeogene fossil wood from Asia remains rarely described. We present here three additional species of fossil wood from the upper member of the Pondaung Formation, including a new species of Menispermoxylon ( M. mowglii nov. spec.) with successive cambia and included phloem, and two specimens of the fossil genera Glutoxylon ( G. burmense Chowdhury) and Heritieroxylon ( H. arunachalensis Lakhanpal, Prakash et Awasthi). These three fossil species are related to modern taxa of mangrove and coastal forests in the Bengal Bay and complete the floral assemblage already identified in the Pondaung Formation. The late middle Eocene fossil woods of Myanmar followed a toposequence with mangroves along the seashore, riparian elements similar to those of modern Terai ecosystem in the upper delta plain, and dry dipterocarp forests in the upstream areas of the drainage basin. The latter two assemblages and their association in the landscape are typical of monsoonal areas with significant rainfall and a marked dry season, thus confirming recent studies showing that the Bengal Bay has experienced a significant monsoonal regime as early as 40 Ma ago. The climatic parameters obtained by two quantitative botanical approaches on the Pondaung fossil wood, the coexistence and wood anatomical approaches, suggest similar-to-modern rainfall amount, marked dry season, and warmer annual temperature for the Eocene of Myanmar. They thus support the hypothesis that monsoonal rainfall at that time may have been favored by Eocene greenhouse conditions. However, despite the homogeneity of the Pondaung floral assemblage, several resulting climatic parameters, such as the mean annual temperature (for the coexistence approach) or the mean annual rainfall (for the wood anatomical approach), display large but incomplete uncertainty intervals or unlikely values (for the coexistence and wood anatomical approaches respectively). These limitations can be attributed to the lack of super-warm and super-seasonal stations in their modern databases. It thus indicates that results from both quantitative approaches should be interpreted with caution for palaeo-monsoon reconstruction.