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In this paper, we report on a new Early Cretaceous vertebrate locality, Phu Din Daeng, in Nakhon Phanom Province, NE Thailand. The Phu Din Daeng site has yielded a diverse vertebrate assemblage, including sharks (Heteroptychodus steinmanni), bony fishes (Pycnodontiformes; Sinamiidae cf. Siamamia and ?Vidalamiinae, and Ginglymodi), adocid turtles, indeterminate neosuchian crocodiles, pterosaurs and dinosaurs (spinosaurids and indeterminate theropods). A new adocid turtle, Protoshachemys rubra n. g. n. sp. is described on the basis of shell material. Field investigations on the geology and comparisons with other vertebrate faunas place Phu Din Daeng in the Sao Khua Formation (Barremian) of the Khorat Group.

International audience; Skull and mandibular elements of a tomistomine crocodilian are described from the late Eocene to early Oligocene lignite seams of Krabi, peninsular Thailand. The Thai tomistomine is a longirostrine form characterized by a rostrum/skull ratio of about 0.6; a mandibular symphysis reaching the level of the eleventh alveolus; a deep participation of the splenial in the symphysis to the level of ninth alveolus; an enlarged fifth maxillary alveolus; long nasals reaching the premaxillae at the level of the fifth maxillary alveolus but not contributing to the external nares; undivided posterior processes of premaxillae; a short prefrontal, excluded by a longer lacrimal from the posteromedial margin of maxillae; vomers visible on the palate. A phylogenetic analysis recovers the Thai specimen among derived tomistomines, on the stem lineage of the extant Tomistoma schlegelii, as a close ally of Maomingosuchus petrolica, a late Eocene tomistomine from southern China. The present recognition of Maomingosuchus sp. in late Eocene Thai deposits expands the distribution of Eocene tomistomines from southern China to the tropics. The origin of Tomistominae in Asia is briefly discussed.; Des éléments crâniens et mandibulaires d’un crocodilien tomistominé sont décrits en provenance de niveaux à lignite de l’Eocène supérieur à Oligocène inférieur de Krabi sur la péninsule Thailandaise. Le tomistominé Thaïlandais est caractérisé par un crâne de type longirostre présentant un ratio rostre/crâne d’environ 0.6 ; une symphyse mandibulaire qui atteint le niveau du onzième alvéole ; une participation profonde du splénial dans la symphyse mandibulaire au niveau du neuvième alvéole ; un cinquième alvéole maxillaire élargi ; les os du nasal qui atteignent les prémaxillaires au niveau du cinquième alvéole maxillaire mais ne participant pas aux narines externes ; des processus postérieurs des prémaxillaires non-divisés ; un préfrontal court, exclu de la marge postéromédiale des maxillaires par un lacrimal plus long ; un vomer visible sur le palais. Une analyse phylogénétique place le spécimen Thaïlandais au sein des tomistominés dérivés, au sein de la lignée de l’actuel Tomistoma schlegelii, et proche de Maomingosuchus petrolica, un taxon de la fin de l’Eocène connu en Chine du sud. La présente découverte de Maomingosuchus sp. dans l’Eocène tardif de Thaïlande étend l’aire de répartition des tomistominés eocènes depuis la Chine du sud jusqu’aux tropiques. L’origine des Tomistominae en Asie est brièvement discutée.

International audience; Skull and mandibular elements of a tomistomine crocodilian are described from the late Eocene to early Oligocene lignite seams of Krabi, peninsular Thailand. The Thai tomistomine is a longirostrine form characterized by a rostrum/skull ratio of about 0.6; a mandibular symphysis reaching the level of the eleventh alveolus; a deep participation of the splenial in the symphysis to the level of ninth alveolus; an enlarged fifth maxillary alveolus; long nasals reaching the premaxillae at the level of the fifth maxillary alveolus but not contributing to the external nares; undivided posterior processes of premaxillae; a short prefrontal, excluded by a longer lacrimal from the posteromedial margin of maxillae; vomers visible on the palate. A phylogenetic analysis recovers the Thai specimen among derived tomistomines, on the stem lineage of the extant Tomistoma schlegelii, as a close ally of Maomingosuchus petrolica, a late Eocene tomistomine from southern China. The present recognition of Maomingosuchus sp. in late Eocene Thai deposits expands the distribution of Eocene tomistomines from southern China to the tropics. The origin of Tomistominae in Asia is briefly discussed.; Des éléments crâniens et mandibulaires d’un crocodilien tomistominé sont décrits en provenance de niveaux à lignite de l’Eocène supérieur à Oligocène inférieur de Krabi sur la péninsule Thailandaise. Le tomistominé Thaïlandais est caractérisé par un crâne de type longirostre présentant un ratio rostre/crâne d’environ 0.6 ; une symphyse mandibulaire qui atteint le niveau du onzième alvéole ; une participation profonde du splénial dans la symphyse mandibulaire au niveau du neuvième alvéole ; un cinquième alvéole maxillaire élargi ; les os du nasal qui atteignent les prémaxillaires au niveau du cinquième alvéole maxillaire mais ne participant pas aux narines externes ; des processus postérieurs des prémaxillaires non-divisés ; un préfrontal court, exclu de la marge postéromédiale des maxillaires par un lacrimal plus long ; un vomer visible sur le palais. Une analyse phylogénétique place le spécimen Thaïlandais au sein des tomistominés dérivés, au sein de la lignée de l’actuel Tomistoma schlegelii, et proche de Maomingosuchus petrolica, un taxon de la fin de l’Eocène connu en Chine du sud. La présente découverte de Maomingosuchus sp. dans l’Eocène tardif de Thaïlande étend l’aire de répartition des tomistominés eocènes depuis la Chine du sud jusqu’aux tropiques. L’origine des Tomistominae en Asie est brièvement discutée.

A new genus and new species of primitive eucryptodiran turtle, Phunoichelys thirakhupti gen. et sp. nov., is described on the basis of shell remains from the lower part of the Phu Kradung Formation, at Phu Noi locality, Kalasin Province, NE Thailand. It is assigned to Xinjiangchelyidae on the basis of the marginals covering the lateral end of the costals and the anal scutes invading the hypoplastra. The new taxon is further characterized by a low and rounded carapace without a cervical notch; the whole carapace and plastron covered with a clear ornamentation consisting of tiny irregular vermiculated furrows; a complete neural series that reaches the suprapygal; a very wide and short cervical scute; relatively wide vertebral scutes; and a long first thoracic rib that extends along the full width of the first costal. The sutured plastron/carapace connection and the marginals covering the lateral end of the second to seventh costals suggest that the turtles from Phu Noi may be related to some primitive xinjiangchelyids from the Sichuan Basin. The discovery of a xinjiangchelyid turtle in the lower part of the Phu Kradung Formation supports a Late Jurassic age for that part of the formation.

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.

Phosphatic remains (tooth enamel, turtle shell fragments and fish scales) of continental vertebrates (freshwater fish, crocodilians, turtles, and theropod and sauropod dinosaurs) recovered from eight localities of NE Thailand ranging in age from the Late Jurassic to the late Early Cretac- eous have been analysed for their oxygen isotopic compositions (d 18 Op). From these preliminary data, local meteoric water d 18 Ow values estimated using d 18 Op values of crocodilians and turtles range from 24.1+ 2‰ at the end of the Jurassic to 28.3+ 2‰ during the Early Cretaceous, suggesting a transition from dry to wetter climates with increasing amount of seasonal precipitation from several hundred millimetres per year to several thousand millimetres. Measurable offsets in d 18 Op values observed between dinosaur taxa (the spinosaurid theropod Siamosaurus, other ther- opods and nemegtosaurid sauropods) are interpreted in terms of differences in water strategies, and suggest that Siamosaurus had habits similar to those of semi-aquatic vertebrates such as crocodi- lians or freshwater turtles.

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; We describe a new species of lungfish, Ferganoceratodus martini sp. nov. , based on a single specimen discovered in the Late Jurassic - Early Cretaceous of the Phu Nam Jun locality, north-eastern Thailand. The material comprises an almost complete skull roof with associated upper and lower jaws, as well as some postcranial remains. F. martini shows characters unexpected and/or unknown in other Mesozoic lungfishes, such as pieces of a 'hard snout'. The microstructure of the 'hard snout' provides support to the Bemis and Northcutt interpretation of the cosmine tissue of Palaeozoic lungfishes as homologous to the complex cutaneous vasculature of the living Neoceratodus . Because the homologies of the ossifications of the skull roof among lungfishes and among piscian sarcopterygians are unsatisfactorily understood, we use a topological nomenclature in the description of the specimen and in the discussion of post-Devonian dipnoan skull roof characters. We define a few characters for the cladistic analysis only, but these are regarded as less theory-laden. We propose a hypothesis of phylogenetic relationships for most of the post-Devonian forms known by skull remains. The main feature is the ancient dichotomy between the Neoceratodus lineage and most of the other Mesozoic forms, including the Lepidosirenids. The palaeobiogeographical pattern shows a series of vicariant events between Laurasia and Gondwana in the Late Triassic - Early Jurassic, followed by a vicariant event between Africa and South America

International audience; dagger Siamamia naga, gen. et sp. nov, is described on the basis of three partly articulated skulls and a collection of isolated ossifications from a continental Early Cretaceous Formation of northeastern Thailand. The new taxon is a dagger sinamiid halecomorph as demonstrated by the median parietal and other cranial characters. dagger Sinamiidae is hitherto known by two genera occurring in Early Cretaceous freshwater deposits in China. Although a complete revision of all species within the family is necessary, the Thai material shows characters justifying a new genus. It is the first dagger sinamiid found outside eastern Asia (South and North Chinese blocks, plus small Central Asian terranes), thus validating the close paleogeographical affinities between mainland Asia and SE Asia in the Early Cretaceous. A preliminary phylogenetic assessment of the new taxon with the data matrix of Grande and Bemis (1998) with the addition of data for dagger Siamamia and dagger Tomognathus provides a strict consensus tree similar to the phylogenetic hypothesis of Halecomorphi proposed by these authors, except the basal-most amiids which show a lower resolution in our hypothesis. The dagger Sinamiidae appear as a monophyletic clade, but the four taxa included in the analysis form a polytomy.

STEPHANE PEIGNE, YAOWALAK CHAIMANEE, CHOTIMA YAMEE, PALADEJ SRISUK, BERNARD MARANDAT, and JEAN-JACQUES JAEGER, Laboratoire de Geobiologie, Biochronologie et Paleontologie humaine – CNRS UMR 6046, Universite de Poitiers, 40, avenue du Recteur Pineau. 86022 Poitiers, France, stephane.peigne@univ-poitiers.fr; Department of Mineral Resources, Geological Survey Division, Rama IV Road. Bangkok 10400, Thailand; Srisuk’s House Museum, 100/11 Moo 1, Khao Yoi, Phetchaburi, 76140, Thailand; Institut des Sciences de l’Evolution – CNRS UMR 5554, USTL-Montpellier II, C.C. 064, Place Eugene Bataillon. 34095 Montpellier cedex 5, France

Recent field research conducted in the middle Miocene basin of Mae Moh, northern Thailand, allow discovering dental remains of a new amphicyonid (Mammalia, Carnivora, Amphicyonidae). A thorough comparison with all known Asian and non-Asian Miocene genera of Amphicyonidae supports the assignment of these specimens to a new amphicyonine, Maemohcyon potisati gen. et sp. nov. We propose the first review of the fossil record of the Amphicyoninae and we discuss the possible geographic origin and phylogenetic relationships of this new taxon. It appears that Maemohcyon does not have close relationships with contemporary ( Amphicyon , Pseudocyon, Ischyrocyon, Pliocyon ) or earlier ( Ictiocyon , Pseudarctos, Cynelos, Ysengrinia ) genera. We suggest that the Maemohcyon lineage probably arrived much earlier than 13 Ma (age of Mae Moh fauna) and evolved in this insulated region until the late middle Miocene.

International audience; We present the first known occurrence of a Mesozoic fossil bird from Thailand. The new specimen is the distal end of a left humerus, from the Early Cretaceous Sao Khua Formation in the Northeast of the country, and testifies to the presence of a medium-sized avian in these non-marine strata. This is also the first Mesozoic bird known from the whole of Southeast Asia.

International audience; In the context of a Thai-French paleontological project, a single human tooth, a right upper fourth premolar, has been discovered in Northern Thailand among mammalian fossil remains excavated from the "Thum Wiman Nakin" cave. Based on the fauna associated with the human tooth and the Uranium/Thorium datings from the overlying calcite beds, we attribute this site to the Late Middle Pleistocene. The human tooth was compared with teeth of Chinese and Javanese Homo erectus, Homo sapiens neanderthalensis and Homo sapiens sapiens as well as teeth of apes (Orang-utan). The tooth has archaic features of the crown which are similar to Homo erectus. It also has derived features of the root which makes it aligns with Neanderthals and modern humans. Consequently, it has been tentatively attributed to Homo sp. Homo remains have not been previously reported from Thailand, and the specimen described here is therefore the first and oldest fossil human remain from this country.

A new species of Cuora, Cuora chiangmuanensis sp. nov., is described on the basis of a nearly complete shell with limb bones from the late Middle – early Late Miocene Chiang Muan Mine, Phayao Province (Northern Thailand). C. chiangmuanensis is distinguished from other fossil and living Cuora species mainly on the basis of its plastral morphology. Among fossil and extant Cuora taxa, the new species appears to be a missing link between the taxa from Southeast Asia and those from East Asia. It represents the earliest record of the genus and demonstrates that by 11–12 Ma, Asian box turtles were already present in Southeast Asia.

Reconstructing the origin and early evolutionary history of anthropoid primates (monkeys, apes, and humans) is a current focus of paleoprimatology. Although earlier hypotheses frequently supported an African origin for anthropoids, recent discoveries of older and phylogenetically more basal fossils in China and Myanmar indicate that the group originated in Asia. Given the Oligocene-Recent history of African anthropoids, the colonization of Africa by early anthropoids hailing from Asia was a decisive event in primate evolution. However, the fossil record has so far failed to constrain the nature and timing of this pivotal event. Here we describe a fossil primate from the late middle Eocene Pondaung Formation of Myanmar, Afrasia djijidae gen. et sp. nov., that is remarkably similar to, yet dentally more primitive than, the roughly contemporaneous North African anthropoid Afrotarsius . Phylogenetic analysis suggests that Afrasia and Afrotarsius are sister taxa within a basal anthropoid clade designated as the infraorder Eosimiiformes. Current knowledge of eosimiiform relationships and their distribution through space and time suggests that members of this clade dispersed from Asia to Africa sometime during the middle Eocene, shortly before their first appearance in the African fossil record. Crown anthropoids and their nearest fossil relatives do not appear to be specially related to Afrotarsius , suggesting one or more additional episodes of dispersal from Asia to Africa. Hystricognathous rodents, anthracotheres, and possibly other Asian mammal groups seem to have colonized Africa at roughly the same time or shortly after anthropoids gained their first toehold there.

International audience; Today and in the Tertiary, the geographical distribution of castorids is limited throughout all of the northern continents. Fossils of the Castoridae genus Steneofiber are abundant in many localities of Eurasia from the late Oligocene to Pliocene period. Recently, Steneofiber fossils were discovered in two localities of northern Thailand, Mae Moh and Chiang Muan coal mines, in layers of late middle Miocene age. These discoveries represent the first records of castorids from Southeast Asia and correspond to their southernmost known range. The focus of this study is to describe this new Thai species of Steneofiber and to define its wear stages from the molar occlusal surfaces by using micro-CT scan analysis. The CT scan technique permits the analysis of the virtual occlusal surface changes from wear, allowing easier comparison to related species of Steneofiber cheek teeth without destroying the teeth. The new species, Steneofiber siamensis n. sp., can be distinguished from the other species of Steneofiber by several distinct characters, longer mesostriid on p4, presence of premesostria and metastria on P4, which are smaller than most of the other known species. The occurrence of this new castorid also supports a subtropical to tropical paleoclimate for these two localities of northern Thailand.

Journal en libre accès ; PDF disponible : http://www.mnhn.fr/museum/front/medias/publication/33834_g2011n1a2.pdf; International audience; Les niveaux mésozoïques du bassin de Muang Phalan au Laos ont livré des restes d'organismes continentaux (vertébrés, mollusques, bois). Les bois avaient été rapprochés d'une espèce connue dans le Lias du Danemark, Brachyoxylon rotnaense Mathiesen, alors que les vertébrés indiquaient plutôt le milieu du Crétacé. Une révision du matériel type de B. rotnaense, de celui de son synonyme taxonomique supposé Simplicioxylon hungaricum Andreánszky, des échantillons lao et de matériel nouveau thaïlandais permet de confirmer la synonymie taxonomique, d'infirmer le rapprochement du matériel lao et de l'espèce européenne et enfin de reconnaître une nouvelle espèce regroupant le matériel lao et thaï, décrite ici sous le nom de B. serrae n. sp. Cette nouvelle espèce de Brachyoxylon est caractérisée par la présence, dans la ponctuation radiale, de groupes de ponctuations contiguës très aplaties et de paires de ponctuations opposées dans de longues files unisériées araucariennes. Notre révision permet de lever l'ambiguïté stratigraphique et confirme la singularité biogéographique de la Péninsule indosinienne au Crétacé inférieur.

International audience

Tarsius is an extant genus of primates endemic to the islands of Southeast Asia that is characterized by enormously enlarged orbits reflecting its nocturnal activity pattern. Tarsiers play a pivotal role in reconstructing primate phylogeny, because they appear to comprise, along with Anthropoidea, one of only two extant haplorhine clades. Their fossils are extremely rare. Here, we describe a new species of Tarsius from the Middle Miocene of Thailand. We reconstructed aspects of its orbital morphology using a geometric–morphometric method. The result shows that the new species of Tarsius had a very large orbit (falling within the range of variation of modern Tarsius ) with a high degree of frontation and a low degree of convergence. Its relatively divergent lower premolar roots suggest a longer mesial tooth row and therefore a longer muzzle than in extant species. The new species documents a previous unknown Miocene group of Tarsius , indicating greater taxonomic diversity and morphological complexity during tarsier evolution. The current restriction of tarsiers to offshore islands in Southeast Asia appears to be a relatively recent phenomenon.

International audience; We report new dental remains of Mustelidae from the late middle Miocene of Mae Moh Basin, northern Thailand, improving the poor fossil record of the family in Southeast Asia. Siamogale thailandica is a poorly known mustelid, previously recorded from just a single tooth. Here we present over a hundred new specimens attributable to this species. S. thailandica shows a combination of primitive and convergent features of the dentition that makes its original subfamilial assignment to Lutrinae doubtful. Evidence from the dental morphology suggests that it belongs to a bunodont otter-like mustelid that evolved in convergence with "true" otters (Lutrinae) toward a semi-aquatic way of life. Autapomorphic features such as the height and the position of the m1 metaconid and the shape of the P4 lingual shelf make S. thailandica unique among Mustelidae. The morphology of this species is mostly similar to Mionictis species and Lartetictis dubia, reported in the Miocene of North America and Europe, respectively. These similarities could imply immigration events to Thailand in the early or middle Miocene. Alternately, the lineage leading to Siamogale might have deeper origins from an endemic early Miocene Southeast Asian mustelid.

International audience; 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.

International audience; A well-preserved fossil talus [National Museum of Myanmar Primates (NMMP) 82] of a large-bodied primate is described from the late middle Eocene Pondaung Formation of central Myanmar. The specimen was collected at Thandaung Kyitchaung, a well-known amphipithecid primate-bearing locality near the village of Mogaung. NMMP 82 adds to a meager but growing sample of postcranial remains documenting the large-bodied primates of the Pondaung Formation. This new talus exhibits a suite of features that resemble conditions found in living and fossil haplorhine primates, notably anthropoids. As such, the phylogenetic signal deriving from the morphology of NMMP 82 conflicts with that provided by NMMP 20, a partial skeleton (including a fragmentary calcaneus) of a second large-bodied Pondaung primate showing undoubted adapiform affinities. Analysis subtalar joint compatibility in a hypothetical NMMP 82/NMMP 20 combination (talus/calcaneus) reveals a substantial degree of functional mismatch between these two tarsal bones. The functional incongruence in subtalar joint morphology between NMMP 20 and NMMP 82 is consistent with the seemingly divergent phylogenetic affinities of these specimens, indicating that two higher level taxa of relatively large-bodied primates are documented in the Pondaung Formation. On the basis of its size and morphology, we refer the NMMP 82 talus to the large-bodied amphipithecid Pondaungia. The occurrence of anthropoid-like tali in the Pondaung Formation obviates the need to invoke homoplasy to explain the shared, derived dental characters that are common to amphipithecids and undoubted anthropoids. Functionally, the NMMP 82 talus appears to have pertained to a primate that is engaged in active quadrupedalism in an arboreal environment along broad and subhorizontal branches. The primate taxon represented by NMMP 82 was capable of climbing and leaping, although it was not particularly specialized for either of these activities.

International audience; The phylogenetic affinities of the primates of the late middle Eocene Pondaung Formation of Myanmar have long been disputed. The discovery of the NMMP 39 talus (Marivaux et al.: Proc Natl Acad Sci USA 100 (2003) 13173-13178) provided the first clear evidence from the postcranium that a relatively large-bodied haplorhine primate is represented in the Pondaung fauna. Another talus (NMMP 82; Marivaux et al., 2010). Talar morphology, phylogenetic affinities and locomotor adaptation of a large-bodied amphipithecid primate from the late middle Eocene of Myanmar, Am J Phys Anthropol DOI: 10.1002/ajpa.21307) has been recently recovered which also pertains to Haplorhini. The metric and nonmetric features supporting the hypothesis of anthropoid affinities for NMMP 39 have been criticized by Gunnell and Ciochon (Gunnell GF, Ciochon RL. 2008. Revisiting primate postcrania from the Pondaung Formation of Myanmar. In: Fleagle JG, Gilbert CC, editors. Elwyn Simons: a search for origins. New York: Springer. p 211-228). Their analysis, however, was based on a very limited choice of variables, taxa, and individuals. Based on an extended sample, we are able to produce both principal components and discriminant functions that yield a rather clear separation of extant haplorhine and strepsirhine tali. Both principal components and discriminant function scores of the Pondaung tali fall with those of haplorhine primates. In addition, the Pondaung tali lack all the derived nonmetric features characteristic of strepsirhine primates, but exhibit all the features characteristic of haplorhine primates. We dispute the features Gunnell and Ciochon (2008) claim are uniquely shared by the Pondaung tali and adapiforms. Their rejection of the phylogenetic significance of the features shared by these tali and haplorhines is unwarranted by the evidence. Based on both metric and nonmetric features, the Pondaung tali are structurally most similar to the tali of haplorhines, particularly anthropoids.

International audience; A new African species of hystricognathous rodent, Gaudeamus lavocati sp. nov., is described herein from the early Oligocene deposits of Zallah locality (Sirt basin, Central Libya). The dental morphology of this species is very close to that of some earliest South American caviomorphs. It allows a reinterpretation of molar crest homologies among earliest caviomorphs, pentalophodonty being confirmed as the plesiomorphic molar condition in Caviomorpha. This morphological resemblance argues for close affinities between Gaudeamus and earliest South American hystricognaths. Cladistic analysis supports Gaudeamus lavocati sp. nov. as the first known African representative of Caviomorpha, implying that its ancestors were part of the African phiomyid group that crossed the South Atlantic by a direct immigration route. Alternatively, the series of derived dental features of Gaudeamus could also be interpreted as evolutionary synchronous convergences of an African hystricognath lineage towards the specialized pattern of some caviomorphs. However, the high level of similarities concerning teeth morphology and enamel microstructure and the similar age of fossiliferous strata on both continents make this interpretation less probable. The phylogenetic position of this taxon is of considerable importance because it represents an enigmatic component of the phiomorph-caviomorph radiation in Africa and appears as a new clue toward the understanding of caviomorph origins.

International audience; Spinosaurs were large theropod dinosaurs showing peculiar specializations, including somewhat crocodile-like elongate jaws and conical teeth. Their biology has been much discussed, and a piscivorous diet has been suggested on the basis of,jaw as well as tooth morphology and stomach contents. Although fish eating has been considered plausible, an aquatic or semiaquatic lifestyle has seldom been suggested because of the apparent lack of corresponding adaptations in the postcranial skeleton of spinosaurs, which on the whole is reminiscent of that of other large terrestrial theropods. On the basis of the oxygen isotopic composition of their phosphatic remains compared with those of coexisting terrestrial theropod dinosaurs and semiaquatic crocodilians and turtles, we conclude that spinosaurs had semiaquatic lifestyles, i.e., they spent a large part of their daily time in water, like extant crocodilians or hippopotamuses. This result sheds light on niche partitioning between large predatory dinosaurs, since spinosaurs coexisted with other large theropods such as carcharodontosaurids or tyrannosaurids. The likely ichlhyophagy and aquatic habits of spinosaurids may, have allowed them to coexist with other large theropods by reducing competition for food and territory.

Northern Thailand comprises more than 40 Tertiary intermontane basins. These basins, tectonically interpreted as grabens or half grabens, have yielded hominoid fossils and rich Neogene mammal faunas. Relative ages provided by biochronological studies are controversial and neither absolute ages nor correlations with marine deposits are available. A precise temporal framework provided by magnetic-polarity stratigraphy is therefore crucial to understand the evolution of these Southeast Asian mammalian faunas, to estimate the timing and duration of basin formation, and finally to allow correlations with other Neogene hominoid localities of the Old World. A complete magnetostratigraphic study, which significantly extends previous paleomagnetic investigations, has been conducted in the Miocene sequence of Mae Moh Basin, Lampang Province, northern Thailand. Based on the biostratigraphic constraints, the 15 polarity zones recognized from the composite section have been correlated with Chrons C5ACr–C5r.3r, between 14.1 and 12.0 Ma. The present study provides a high-resolution magnetostratigraphic reference for the continental middle Miocene of all Southeast Asia. By correlation with the Miocene sequence of the nearby basin of Chiang Muan, the large-bodied hominoid ( Khoratpithecus chiangmuanensis )–bearing levels can be precisely dated between 12.4 and 12.2 Ma.

International audience; Amphipithecids assume a key position in early primate evolution in Asia. Here we report on new maxillofacial and associated mandibular remains of Siamopithecus eocaenus, an amphipithecid primate from the Late Eocene of Krabi (Thailand) that currently represents the most complete specimen belonging to this group. We used synchrotron microtomography and techniques of virtual reconstruction to recover the three-dimensional morphology of the specimen. Geometric-morphometric analysis of the reconstructed specimen within a comparative sample of recent and fossil primates clearly associates Siamopithecus with the anthropoids. Like modern anthropoids, Siamopithecus displays a relatively short face and highly convergent and frontated orbits, the lower rim of which lies well above the alveolar plane. The cooccurrence of spatially correlated anthropoid features and classical anthropoid dental characters in one individual represents a strong argument to support the anthropoid status of Siamopithecus. It is, thus, highly unlikely that amphipithecids are specialized adapiforms exhibiting complete convergence with anthropoids.

The family Amphipithecidae is one of the two fossil primate taxa from Asia that appear to be early members of the anthropoid clade. Ganlea megacanina , gen. et sp. nov., is a new amphipithecid from the late middle Eocene Pondaung Formation of central Myanmar. The holotype of Ganlea is distinctive in having a relatively enormous lower canine showing heavy apical wear, indicating an important functional role of the lower canine in food preparation and ingestion. A phylogenetic analysis of amphipithecid relationships suggests that Ganlea is the sister taxon of Myanmarpithecus , a relatively small-bodied taxon that has often, but not always, been included in Amphipithecidae. Pondaungia is the sister taxon of the Ganlea + Myanmarpithecus clade. All three Pondaung amphipithecid genera are monophyletic with respect to Siamopithecus , which is the most basal amphipithecid currently known. The inclusion of Myanmarpithecus in Amphipithecidae diminishes the likelihood that amphipithecids are specially related to adapiform primates. Extremely heavy apical wear has been documented on the lower canines of all three genera of Burmese amphipithecids. This distinctive wear pattern suggests that Burmese amphipithecids were an endemic radiation of hard object feeders that may have been ecological analogues of living New World pitheciin monkeys.

Thailand's geographical location in the tropics and almost complete, relatively uninterrupted forest cover makes it valuable for paleodiet and paleoclimate research. We present the first dietary and environmental reconstructions in Northeastern Thailand, using stable isotope abundances in mammalian tooth enamel from the late Middle Pleistocene locality, Tham Wiman Nakin (Snake Cave), which reflect a much higher (over 70%) than modern (13%) occurrence of C4 plants. Bovids and cervids appear to have had almost entirely a C4 plant diet. Carnivores consumed a mixture of C3 (suids) and C4 (bovids, cervids) consumers. Rhinoceroses and orangutan appear to have maintained their preference through time for forested or open C3 environment, respectively. (13)C/(12)C from bone bioapatite, horn and hair of modern Southeast Asian mammals almost exclusively demonstrate C3 vegetation dominance. C4 consumption is rare in analysed modern species and it could be related to anthropogenic influences such as ingestion of domestic crops or livestock. Interesting implications emerge in the C4 vegetation distribution in southern Eurasian ecosystems, indicating that Southeast Asia, south of the Tibet, could be part of the global C4 vegetation spread, which occurred around 7 Ma. However, the C4 percentage in ecosystems varied geographically. Despite modern reversal towards C3 habitats due to factors such as increasing CO(2), we think that anthropological influences may be responsible for habitat and dietary changes in extant species. Bovids demonstrate the most significant shift in diet and habitat through time, from C4-dominated open habitats to C3-dominated habitats indicative of dense forest understory.

The proboscidean fauna of the middle Miocene of Thailand consists of five taxa, including four elephantoids and one deinothere. The Thai association is dominated by the genera Stegolophodon and Gomphotherium. Stegolophodon is represented by S. nasaiensis and S. praelatidens. The latter species, considered invalid and possibly conspecific with S. latidens, is re-erected. Its phylogenetic relationships are discussed. The Thai Gomphotherium matches with G. browni from the middle Miocene of Indo-Pakistan. However, the open nomenclature is employed for the Thai material because it differs from G. browni in terms of curvature of the upper tusk. Intraspecific molar size variation observed in G. cf. browni and Stegolophodon praelatidens is attributed to sexual dimorphism. The Thai proboscidean asssemblage is mainly endemic compared with other contemporaneous Asian faunas although the recognition of Gomphotherium cf. browni denotes faunal affinities with Pakistan. The biostratigraphical implications of the taxa are examined in a regional context. © 2009 The Linnean Society of London, Zoological Journal of the Linnean Society, 2009, 155, 703–721.

Paleogene faunas from Southeast Asia are rare and mainly represented by those from Krabi (late Eocene, Thailand) and Pondaung (middle Eocene, Myanmar). The late Oligocene locality of Nong Ya Plong (Thailand) was discovered recently and has so far yielded mammalian remains representing the orders Carnivora, Dermoptera, Rodentia, and Perissodactyla. A new genus and species from this locality (Siamosorex debonisi n. gen., n. sp.) of the soricoid family Plesiosoricidae is described. The material consists of lower dentitions only. The species differs from other plesiosoricids in being larger to much larger (except compared to some species of Plesiosorex) and in having a shallow masseteric fossa; i2 enlarged, not procumbent but upright and caniniform, with a deep mesiolingual groove; elongated, double-rooted p3 and p4, similar in length but p3 with simple crown and p4 semimolariform with a reduced paraconid, a high, distinct metaconid, and a short talonid; lower molars decrease in size strongly from m1...

Teeth from the Early Cretaceous Napai Formation of Fusui County, Guangxi Zhuang Autonomous Region (South China), initially described as the sauropterygian Sinopliosaurus fusuiensis, are redescribed as belonging to a spinosaurid theropod closely allied to Siamosaurus suteethorni, from the Early Cretaceous of Thailand. This identification extends to China the geographical range of Asian spinosaurs, previously reported from Thailand and Japan.

The postcranial anatomy of the Asian sivaladapid adapiforms is still virtually undocumented, whereas dental remains of these primates have been known for several decades. Little is known about their positional behavior as a result. In this article, we describe a partial left femur of a medium-sized primate preserving its entire proximal portion and a significant length of its shaft. This fossil was recently recovered from the fossiliferous locality of Thamingyauk in the late middle Eocene Pondaung Formation (central Myanmar). This femur is considered to pertain to the same individual as two tarsal elements (fragmentary talus and calcaneus) from the same locality (same location), and attributed to a medium-sized sivaladapid adapiform primate (Kyitchaungia takaii). This new postcranial element provides the first documentation of femoral anatomy among Sivaladapidae from Asia. The mechanical implications deriving from the musculoskeletal interpretation of this bone indicate an animal that probably engaged in a kind of active arboreal quadrupedalism with some degree of proficiency in leaping. Even though many musculoskeletal aspects suggest that branch walking and running were important parts of its locomotor repertoire, in other details it appears that relatively complex movements at the hip joint were actually possible and probably associated with climbing or some hindlimb suspensory activities.

Sivaladapids are a group of Asian adapiform primates that were previously documented from deposits dating to the middle Eocene through the late Miocene in Pakistan, India, Myanmar, Thailand, and China. The group is notable for the persistence of three genera, Sivaladapis, Indraloris and Sinoadapis, into the late Miocene. In Thailand, sivaladapids were previously documented only from late Eocene deposits of the Krabi mine. Here, we describe the first Southeast Asian Miocene sivaladapid, Siamoadapis maemohensis gen. et sp. nov. from a 13.3 to 13.1 Ma lignite layer from the Mae Moh coal mine, Thailand. It differs from other Miocene sivaladapids by its distinctly smaller size and in features of the dentition. This discovery enhances the paleoecological diversity of the middle Miocene primate fauna of Thailand, which now includes sivaladapids, a loris, tarsiids, and hominoids. In this respect, the fossil primate community from the middle Miocene of Thailand is similar in its composition to roughly contemporaneous assemblages from southern China, India, and Pakistan. However, the Thai fossils represent a distinct genus, suggesting a different biogeographic province with distinctive paleoenvironments.

New fossil remains of the anthracothere genus Merycopotamus Falconer and Cautley, are described. Most of them were discovered by the Harvard University and Geological Survey of Pakistan joint research project (Y-GSP) in the well-dated Middle and Late Miocene deposits of the Potwar Plateau in northern Pakistan. This new material led us to revise the systematics of the genus with the validation of three species, M. nanus Falconer (M. pusillus Lydekker), M. dissimilis Falconer and Cautley, and M. medioximus Lihoreau et al., and allowed us to determine precisely their chronological distributions in a continuous Neogene sequence. Other specimens reported from the late Miocene deposits of the Khorat Plateau in north-east Thailand by the Department of Mineral Resources are the first remains of Merycopotamus to have been discovered in that region and are attributed to M. medioximus. These discoveries indicate a wider geographical distribution of the genus in the early Late Miocene. Anatomical investigations highlight the evolution of Merycopotamus through the Miocene towards more amphibious habits. Palaeobiogeographical and palaeoecological information for Merycopotamus stress the role of the Himalayan orogenesis as a dispersal barrier and the impact of a major global regression event on the evolution of Indian Subcontinent faunas from the Middle Miocene to the Late Pliocene.

We report here the first discovery of microvertebrates from the Mae Moh coal mine, Lamphang Province, northern Thailand. This discovery sheds new light on the age and paleoenvironments of the Miocene basins of northern Thailand. Previous investigations of paleomagnetic stratigraphy in the Mah Moh Basin demonstrated that the fossiliferous Q and K coal seams there date between 13.12–13.3 Ma. The microvertebrate fauna from the Q and K coal seams includes Tarsius sp., erinaceid insectivores and rodents, the last being represented by the monospecific genera Prokanisamys and Neocometes. These microvertebrate fossils are extremely similar to elements of the Mae Long fauna from the Li Basin, which had been estimated to date between 16–18 Ma. Accordingly, the Mae Long fauna in the Li Basin appears to be contemporaneous with the fauna from the Q and K coal seams in the Mae Moh Basin, suggesting that previous estimates of the age of the Mae Long fauna were 3–5 Ma too old. The discovery of numerous fragments...

International audience

Fossil primates from the late middle Eocene Pondaung Formation of Myanmar have figured prominently in recent efforts to reconstruct the early evolutionary history of anthropoids. The anthropoid affinities of Amphipithecidae, the most abundant fossil primates currently known from the Pondaung Formation, have proven to be particularly controversial. Here we describe two new genera and species, Paukkaungia parva and Kyitchaungia takaii, of sivaladapid primates from the Pondaung Formation. Tarsal elements that are appropriate in size and morphology to belong to Kyitchaungia takaii are also described. These are the first undoubted adapiforms—and the first fossil primates other than anthropoids—to be reported from the Eocene of Myanmar. The discovery of sivaladapids in the Pondaung Formation enhances the taxonomic and paleoecological diversity of the late middle Eocene primate fauna of Myanmar. In this respect, the fossil primate community from the Pondaung Formation appears to have resembled roughly c...

International audience; We describe here a mammalian assemblage originating from the locality of Chaungtha (Irrawaddy Formation, Myanmar). It represents one of the rare descriptions of a precisely located, in space, vertical section and time, fossil mammal fauna from the Irrawaddy Formation. Classically the fossil record of Irrawaddy Formation is essentially known from isolated fossils of imprecise or unknown provenance, especially concerning the stratigraphic position of the fossils along several hundred meter thick sections. The Chaungtha faunal association consists of the rhino Brachypotherium fatehjangense, the pig Conohyus thailandicus, the ruminants cf. Siamotragulus sanyathanai, cf. Siamotragulus sp. and a gomphotheriid proboscidean. This assemblage indicates that the locality is Miocene in age, and not Late Eocene as previously claimed, and roughly contemporaneous with the Chinji Formation of India-Pakistan (ca. 14 to 11 Ma) and with the Mae Moh Group of northern Thailand. The Chaungtha fauna, even if it displays regional characteristics, shows a strong resemblance to those of the Middle Miocene of India-Pakistan and of Thailand and reinforces the idea that South-East Asia and Pakistan were part of the same biogeographical province during the Middle Miocene.

The genus Khoratpithecus, a hominoid thought to be related to the orangutan lineage, is represented by two known fossil species K. chiangmuanensis and K. piriyai. Both were discovered in Southeast Asia (Thailand) and are dated to the Middle and Late Miocene, respectively. In this study, dental topographic and microwear texture analyses were used to examine molars from both of these species, with the goal of understanding their dietary preferences. Although sample sizes are small for Khoratpithecus, available data are compared to that collected for extant apes. Environmental evidence, such as botanical remains and sedimentological data, is also considered for comparisons with dietary reconstruction. Results from dental topographic analysis suggest that the two fossil species were better adapted to a diet of fruits than to one of leaves, much like the living orangutan or chimpanzee. Results from microwear texture analysis further support this, suggesting that Khoratpithecus preferred soft fruits to hard fruits or seeds. And finally, the botanical and sedimentological evidence point to environments for Khoratpithecus that would have been compatible with a fruit-eating species. Given the small sample sizes available for analysis, however, definitive judgments are not yet possible at this time.

Cynocephalid dermopterans (flying lemurs) are represented by only two living genera (Cynocephalus and Galeopterus), which inhabit tropical rainforests of South-East Asia. Despite their very poor diversity and their limited distribution, dermopterans play a critical role in higher-level eutherian phylogeny inasmuch as they represent together with Scandentia (tree-shrew) the sister group of the Primates clade (Plesiadapiformes + Euprimates). However, unlike primates, for which the fossil record extends back to the early Palaeogene on all Holarctic continents and in Africa, the evolutionary history of the order Dermoptera sensu stricto (Cynocephalidae) has so far remained undocumented, with the exception of a badly preserved fragment of mandible from the late Eocene of Thailand (Dermotherium major). In this paper, we described newly discovered fossil dermopterans (essentially dental remains) from different regions of South Asia (Thailand, Myanmar, and Pakistan) ranging from the late middle Eocene to the late Oligocene. We performed microtomographic examinations at the European Synchrotron Radiation Facility (ESRF, Grenoble, France) to analyse different morphological aspects of the fossilized jaws. The abundant material from the late Oligocene of Thailand (Nong Ya Plong coal mine) allows us to emend the diagnosis of the genus Dermotherium and to describe a new species: Dermotherium chimaera sp. n. This species exhibits an interesting mosaic of plesiomorphic cynocephalid characters shared with Cynocephalus and Galeopterus, and as such, it probably documents a form close to the ancestral morphotype from which the two extant forms are derived (supported by cladistic assessment of the dental evidence). The discovery of Palaeogene cynocephalids is particularly significant since it attests to the great antiquity of the order Dermoptera in Asia, and besides, it provides the first spatio-temporal glimpse into the evolutionary history of that enigmatic mammal group. In that respect, these fossils testify to a long history of endemism in South Asia for dermopterans, and demonstrate that their modern geographic restriction in south-eastern Asia is clearly a relictual distribution. Cynocephalids had a more widespread distribution during the Palaeogene, which extended from the Indian subcontinent (the rafting Greater India) to South-East Asia. Their subsequent extinction on the Indian subcontinent was probably mediated by the major palaeogeographic and geomorphologic events related to the India-Eurasia collision (retreat of the Paratethys Sea, formation of orogenic highlands) that have strongly affected the climate of South Asia at the end of the Oligocene.

International audience; The discovery of a new elasmobranch assemblage from the Lower Cretaceous of Thailand allows expansion of the faunal list and refinement of our knowledge of the dental morphological features of some previously described taxa. The root morphology of Thaiodus is now known and a more complete description of the dentition of the genus Heteroptychodus, known formerly by a single tooth from Japan, is given. A new genus and species, Acrorhizodus khoratensis, characterized by teeth of very special morphology is described. Besides these taxa, some teeth of a genus probably close to Hybodus, but with more bulbous teeth, are present. Owing to the sedimentological characters of the deposits and the associated fauna (dinosaurs), it is probable that this elasmobranch fauna lived in a freshwater or brackish environment. The simultaneous occurrence of teeth of Heteroptychodus in Thailand and Japan favours the existence of a large continental area in south-east Asia during the Early Cretaceous.

A Khoratpithecus piriyai lower jaw corresponds to a well-preserved Late Miocene hominoid fossil from northeastern Thailand. Its morphology and internal structure, using a microcomputed tomography scan, are described and compared to those of other known Miocene hominoids. It originated from fluviatile sand and gravel deposits of a large river, and was associated with many fossil tree trunks, wood fragments, and large vertebrate remains. A biochronological analysis by using associated mammal fauna gives an estimated geological age between 9-6 Ma. The flora indicates the occurrence of a riverine tropical forest and wide areas of grassland. K. piriyai displays many original characters, such as the great breadth of its anterior dentition, suggesting large incisors, large lower M3, a canine with a flat lingual wall, and symphysis structure. Several of its morphological derived characters are shared with the orangutan, indicating sister-group relationship with that extant ape. This relationship is additionally strongly supported by the absence of anterior digastric muscle scars. These shared derived characters are not present in Sivapithecus, Ankarapithecus, and Lufengpithecus, which are therefore considered more distant relatives to the orangutan than Khoratpithecus. The Middle Miocene K. chiangmuanensis is older, displays more primitive dental characters, and shares several dental characters with the Late Miocene form. It is therefore interpreted as its probable ancestor. But its less enlarged M3 and more wrinkled enamel may suggest an even closer phylogenetic position to orangutan ancestors, which cannot yet be supported because of the incomplete fossil record. Thus Khoratpithecus represents a new lineage of Southeast Asian hominoids, closely related to extant great ape ancestors.

International audience; Asian tarsiid and sivaladapid primates maintained relictual distributions in southern Asia long after the extirpation of their close Holarctic relatives near the Eocene-Oligocene boundary. We report here the discovery of amphipithecid and eosimiid primates from Oligocene coastal deposits in Pakistan that demonstrate that stem anthropoids also survived in southern Asia beyond the climatic deterioration that characterized the Eocene-Oligocene transition. These fossils provide data on temporal and paleobiogeographic aspects of early anthropoid evolution and significantly expand the record of stem anthropoid evolution in the Paleogene of South Asia.

International audience; We report on very small fossil eggs from the Lower Cretaceous of Thailand, one of them containing a theropod embryo, which display a remarkable mosaic of characters. While the surficial ornamentation is typical of non-avian saurischian dinosaurs, the three-layered prismatic structure of the eggshell is currently known only in extant and fossil eggs associated with birds. These eggs, about the size of a goldfinch's, mirror at the reproductive level the retention of small body size that was paramount in the transition from non-avian theropods to birds. The egglayer may have been a small feathered theropod similar to those recently found in China.

International audience; A vertebra collected from the Jurassic non-marine Khlong Min Formation of southern Thailand is referred to the family Euhelopodidae, a group of sauropod dinosaurs that apparently was endemic to eastern Asia during the Jurassic and Early Cretaceous, at a time when that part of the world was isolated from other land masses. The occurrence of a euhelopodid in the Jurassic of the Shan–Thai Block supports the idea of a collision of the Shan–Thai Block with the Indochina Block, thus establishing connections with ‘mainland Asia', early in the Mesozoic, probably before the Jurassic.

The earliest rhinocerotids from South Asia are identified on the basis of few dental remains originating from the Late Eocene of Thailand (Wai Lek mine, Krabi Basin) and the Early Oligocene of Pakistan (Paali nala C2, Bugti Hills). Once synthesized, the Holarctic Paleogene rhinocerotid record points out a westward diachronism of rhinocerotid First Appearance Data, from North America to Europe via Asia, throughout mid-Cenozoic times. The faunal similarity among mammal localities from the Late Eocene and Early Oligocene of peninsular Thailand, southern China, and Pakistan suggests the existence of a single South Asian paleoprovince during this interval and the persistence of a tropical-subtropical climate. Substantial faunal changes recorded in eastern Balochistan reveal a significant climatic deterioration from the middle part of the Oligocene. Neither provinciality nor endemism is noticeable for rhinocerotoid taxa recognized in the Oligocene of the Indian subcontinent: neither the Himalayas nor the Tibet Plateau was a paleogeographic barrier for large mammals during this interval. Resume : Les plus anciens rhinocerotides d'Asie du Sud sont identifies grâce a quelques restes dentaires provenant de l'Eocene superieur de Thailande (Mine de Wai Lek, Bassin de Krabi) et de l'Oligocene inferieur du Pakistan (Paali nala C2, Collines Bugti). La synthese du registre fossile paleogene holarctique des rhinocerotides revele un net diachronisme des premieres apparitions de rhinocerotides depuis l'est (Amerique du Nord) vers l'ouest (Asie, puis Europe) au cours du Cenozoique moyen. La similarite des communautes de mammiferes entre les localites de l'Eocene superieur et de l'Oligocene inferieur de Thailande peninsulaire, de Chine du Sud et du Pakistan, suggere l'existence d'une seule Paleoprovince sud-asiatique pendant la periode consideree, sous un climat tropical a subtropical. Les changements fauniques enregistres au Balouchistan oriental revelent une deterioration climatique significative a partir du milieu de l'Oligocene. Aucun indice de provincialisme ou d'endemisme n'est releve pour les rhinocerotoides oligocenes du Sous-continent indien : ni les Himalayas ni le Plateau du Tibet ne constituaient a l'epoque une barriere paleogeographique pour les grands mammiferes.