New cynodonts (Therapsida, Eucynodontia) from the Late Triassic of India and their significances

The Upper Triassic Tiki Formation of India has yielded several new cynodont taxa, which are described on the basis of multiple isolated teeth and a jaw fragment. A new species of dromatheriid,Rewaconodon indicus, is defined by a tri- and tetracuspid asymmetric crown, long anterior edge of the major cuspa, cingular cuspsdandf, and marked constriction at the crown-root junction. Another new dromatheriid,Inditherium florisn. gen. n. sp., is characterized by a broad, flower-shaped pentacuspid crown, multiple cingular cusps, and a weak lingual cingulum is also described from the same horizon. In addition, a new mammaliamorph taxon,Tikiodon cromptonin. gen. n. sp., is established on a tooth specimen, which has a shovel-shaped crown, three closely spaced main cusps, a pronounced lingual cingulum with multiple cingular cusps, and a root of incomplete root bifurcation. Such a tooth morphology occupies an intermediate position between the non-mammalian cynodonts and the early mammals, as is evident from the co-occurrence of various cynodont dental morphotypes in the Tiki Formation. Moreover, Late Triassic cynodonts occurred along narrow belts demarcated by paleolatitudes, though the Indian fauna shows both Laurasian and Gondwanan affinities.UUID:http://zoobank.org/c2c575ad-ee23-4f33-8a30-661c548a5b17