The lower Eocene (Ypresian) Cambay Formation at Vastan Lignite Mine in Gujarat, western India, has yielded a rich vertebrate assemblage including the earliest modern mammals and oldest birds of the Indian subcontinent. Among the herpetological faunas, snakes, lizards and amphibians are abundant, but, strangely, lizards are only represented by agamids. Here we describe the agamid assemblage based on numerous, diverse and well-preserved dentaries, premaxillaries, and maxillaries. At least four taxa are present at Vastan. Vastanagama susanae is characterized by dentaries with a large symphyseal facet, three anterior pleurodont teeth followed by acrodont teeth presenting a main cusp bordered by two lateral crests; the teeth increase in size posteriorly toward the coronoid process. Tinosaurus indicus exhibits a subdental ridge between the tooth row and the Meckelian canal, pleurodont symphyseal teeth including one that can be caniniform, and acrodont and tricuspid posterior teeth with poorly differentiated lateral cusps. Two other taxa represent two new genera and species. The first taxon presents multicuspid acrodont teeth with the main cusp surrounded by two or three progressively smaller lateral cusps. The second taxon presents pleurodont anterior teeth followed by a few acrodont teeth and ending with three or four subacrodont teeth near the coronoid process. Our results confirm that Agamidae (assigned to the Acrodonta) is the only lizard group present at Vastan, whereas many other groups are already present in the Early Eocene on the other continents. Agamidae is considered to have had a Gondwanan origin, with 52 genera and 420 species of extant agamids known from Asia, Australia, Africa and a few from Southern Europe. The oldest occurrence of formally recognized Acrodonta is found in the Jurassic of India. Other fossil agamids are known in the Upper Paleocene of Kazakhstan, Paleocene and Eocene of China, Early Eocene of Europe, Eocene of North America, and Middle Eocene of Pakistan. The diversity of the agamids in India and the absence of other lizard groups at Vastan tentatively support the Out-of-India hypothesis for agamids.
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The early to middle Selandian fossiliferous Orp Sand Member of the Heers Formation in Belgium has regularly been excavated at its type-locality Maret for its rich and diversified selachian fauna. Among the abundant vertebrate remains, extremely rare mammal specimens have been found. Three isolated teeth have been published previously, all with uncertain affinities. The purpose of this study is to present new specimens from the same deposits, including a small well-preserved dentary of an adapisoriculid attributable to “Afrodon” germanicus, a fragmentary upper molar, referred to Berrulestes sp., and a premolar of a large arctocyonid. Among the previous specimens we identified Arctocyonides cf. weigelti. The adapisoriculid dentary offers new clues that allow transferring “Afrodon” germanicus to the genus Bustylus. The five mammal taxa from Maret indicate an age intermediate between reference-levels MP1-5 of Hainin, Belgium and MP6 of Cernay, France and present the greatest correlation with the rich Walbeck fauna in Germany. The deposits from Walbeck were usually thought to be slightly older than the late Thanetian deposits of Cernay. We infer here that the age of Walbeck is likely to be Selandian. The strong differences observed between Hainin on the one hand, and Walbeck and Cernay on the other hand, document a dispersal event from North America to Europe around the Danian-Selandian boundary.
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