An ailuravine rodent from the lower Eocene Cambay Formation at Vastan, Western India, and its palaeobiogeographic implications

A new ailuravine rodent, Meldimys musak sp. nov. (Mammalia: Rodentia, Ischyromyidae), is recorded from the lower Eocene lignites of western India. It is the oldest record of Rodentia from India. M. musak is more derived than the earliest Eocene ailuravine Euromys cardosoi from Portugal and more generalized than late early Eocene E. inexpectatus and Ailuravus michauxi from France. Its dental morphology closely corresponds to the middle early Eocene species M. louisi, which lived about 52 Ma in Western Europe. Meldimys was previously known only from Europe, and ailuravines were previously reported only from Europe and North America. Its occurrence in India allows the first direct correlation between the early Eocene land mammal horizons of Europe and India, and raises the possibility of a terrestrial faunal exchange between India and Eurasia close to the Palaeocene-Eocene transition

First tillodont from India: additional evidence for an early Eocene faunal connection between Europe and India?

Vastan LigniteMine in southeastern Gujarat, India, produces the oldest known Cenozoic land-mammals and the only early Eocene continental vertebrate fauna known from India (e.g., Bajpai et al. 2005; Rana et al. 2005, 2008; Rose et al. 2006, 2008, 2009; Smith et al. 2007; Rage et al. 2008). The fauna co- mes from the Cambay Shale Formation and has been dated as middle Ypresian (~52Ma, early Cuisian) based on a common nummulitid foraminiferan from about 15 m above the verte- brate-producing layer (Sahni et al. 2006; Rana et al. 2008). However, a recent study of dinoflagellate cysts from the sec- tion suggests that the deposits may be as old as 54-55 Ma (Garg et al. 2008). Although some elements of the fauna, such as anthracobunids and lagomorphs, have Asian affinities, a surprising number of taxa among the snakes, bats, insecti- vores, primates, rodents, and artiodactyls appear to be most closely related to early Eocene European or North American taxa. This may simply reflect the poor state of knowledge of contemporary south Asian vertebrate faunas; alternatively, it might be evidence of previously unsuspected early Eocene faunal exchange between Europe and southwest Asia.We report here two teeth of a tillodont from Vastan Mine, which constitute the first record of the mammalian order Tillodontia known from India. Despite the much greater generic diversity of tillodonts inAsia than elsewhere, theVastan tillodont shows clear affinities with Euramerican esthonychines

Early Eocene artiodactyls (Mammalia) from Western India

The Cambay Formation at Vastan Mine in Gujarat, western India, has yielded the oldest artiodactyls and other land mammals from India, which are dated as middle Ypresian (~53 Ma) based on foraminiferids. Here we describe new dentitions, including dentaries and upper teeth of Diacodexis indicus (= Gujaratia indica) from Vastan. These provide better characterization of this Asian diacodexeid (Artiodactyla: Mammalia) than was available earlier. A new combination, Diacodexis indicus, is proposed in place of Gujaratia indica, and G. pakistanensis is referred back to Diacodexis. A new, very small species of Diacodexis, D. parvus, is reported based on isolated teeth. Whereas D. indicus is approximately the size of the largest known species of Diacodexis, D. parvus represents the smallest recorded species of the genus and is one of the smallest known artiodactyls. Diacodexeidae indet. from Vastan is exemplified by a fragment of a dentary and an upper molar, which are of intermediate size. Several isolated teeth represent a new genus and species, unrelated to Diacodexeidae, and are assigned to Artiodactyla indet. pending discovery of more adequate specimens. Early Eocene diacodexeid postcrania are described for the first time from India. Early Eocene artiodactyls from India are phenetically close to Euroamerican species of Diacodexis, providing further evidence of phylogenetic connections particularly with European faunas. A few postcranial features of the Vastan artiodactyls are also seen in primitive archaeocetes (Cetacea) indicating a possible relationship between Vastan artiodactyls and basal Cetacea

Early Eocene primates from Gujarat, India

The oldest euprimates known from India come from the Early Eocene Cambay Formation at Vastan Mine in Gujarat. An Ypresian (early Cuisian) age of ~53 Ma (based on foraminifera) indicates that these primates were roughly contemporary with, or perhaps predated, the India-Asia collision. Here we present new euprimate fossils from Vastan Mine, including teeth, jaws, and referred postcrania of the adapoids Marcgodinotius indicus and Asiadapis cambayensis. They are placed in the new subfamily Asiadapinae (family Notharctidae), which is most similar to primitive European Cercamoniinae such as Donrussellia and Protoadapis. Asiadapines were small primates in the size range of extant smaller bushbabies. Despite their generally very plesiomorphic morphology, asiadapines also share a few derived dental traits with sivaladapids, suggesting a possible relationship to these endemic Asian adapoids. In addition to the adapoids, a new species of the omomyid Vastanomys is described. Euprimate postcrania described include humeri, radii, femora, calcanei, and tali, most of which show typical notharctid features and are probably attributable to asiadapines. Anatomical features of the limb elements indicate that they represent active arboreal quadrupedal primates. At least one calcaneus is proximally shorter and distally longer than the others, resembling eosimiids in this regard, a relationship that, if confirmed, would also suggest an Asian or southeast Asian faunal connection. Isolated teeth from Vastan Mine recently attributed to a new eosimiid, Anthrasimias gujaratensis, appear to provide that confirmation. However, their attribution to Eosimiidae is equivocal. They are similar to teeth here tentatively referred to Marcgodinotius, hence A. gujaratensis may be a junior synonym of M. indicus. Corroboration of eosimiids at Vastan requires more compelling evidence. Although definitive conclusions are premature, available evidence suggests that the Vastan adapoids, at least, were derived from western European stock that reached India near the Paleocene-Eocene boundary

Quercypsitta-like birds from the early Eocene of India (Aves,? Psittaciformes)

We report new avian remains from the early Eocene Cambay Formation of Vastan Lignite Mine in western India. Most of the bones belong to the as yet poorly known taxon Vastanavis, of which a new species, V. cambayensis, is described. For the first time, tarsometatarsi of Vastanavis can be identified, which show that this taxon had semi-zygodactyl feet. In overall morphology, Vastanavis closely resembles the species of the Quercypsittidae, which occur in the late Eocene of Europe and are considered stem group representatives of the parrots (Psittaciformes). Several plesiomorphic features indicate, however, that Vastanavis is outside a clade including Quercypsitta and crown group Psittaciformes, and we therefore assign it to a new family, Vastanavidae. Vastanavis corresponds well with an as yet undescribed avian species from the early Eocene London Clay in England, and we conclude that, at least concerning the arboreal taxa, the early Eocene avifauna of India shows some concordances with the much better known one from the early Eocene of Europe. We further describe a distal tarsometatarsus from Vastan Lignite Mine that superficially resembles that of extant New World vultures (Cathartidae), but comes from a roller-sized species