NEW DINOSAUR REMAINS FROM THE LATE TRIASSIC OF CENTRAL INDIA

NOVAS, F. E.; CHATTERJEE, S.; EZCURRA, M. D.; KUTTY, T. S.

Bristol

Congreso; 69th Annual Meeting Society of Vertebrate Paleontology; 2009

Until recently the sole Triassic dinosaur fossil from India was represented by the basalsaurischian Alwalkeria, which came from the lower part of the Upper Triassic MaleriFormation (late Carnian-early Norian) of the Pranhita-Godavari Valley. With the discoveryof new dinosaur fossils from the younger horizons of the same basin, we enlarge thedinosaurian faunal list. The new fossil assemblages were recovered from the Upper Maleri(Norian) and Lower Dharmaram (Norian-Rhaetian) formations respectively, and thematerial is housed at the Geology Museum of the Indian Statistical Institute (ISI), Kolkata.Preliminary identifications of specimens from the Upper Maleri Formation reveal thefollowing dinosaurs: ISI R282 resembles herrerasaurs in having a vertically oriented pubicshaft and absence of a brevis fossa; ISI R284 apparently belongs to a basal saurischianof uncertain affinities; ISI R277 resembles basal sauropodomorphs (e.g., Guaibasaurus,Saturnalia, Panphagia) in the presence of an iliac acetabular wall incipiently open, andpostacetabular process longer than the acetabular length; ISI R273 and ISI R274 aresauropodomorphs closely related with plateosaurians due to the presence of ilium thatlacks a buttress between the preacetabular process and supraacetabular crest, metatarsalI with an angled distal end, and metatarsal V proximal wide, representing more than 30percent of its whole length. The younger Lower Dharmaram Formation has yielded remainsof medium-sized sauropodomorphs (ISI R280 and 281), and a femur of a coelophysoidtheropod (ISI R283), the latter represents the first definite member of this clade from India.The new material provides a more complete dinosaur faunal succession for the UpperTriassic in India, including basal saurischians, a variety of primitive sauropodomorphs, andcoelophysoid theropods. This composition of the Indian Triassic dinosaur faunas is similar tothat of Upper Triassic horizons of South America, South Africa, and Europe in the Pangeanworld.