The ornithischian diversity on the Cañadon Asfalto Formation.

BECERRA, MARCOS G.; POL, DIEGO; RAUHUT, OLIVER W.M.

Trelew, Chubut

Simposio; V Simposio Argentino del Jurásico; 2013

Museo Paleontológico Egidio Feruglio

The diversity of the Lower to Middle Jurassic ornithischians is represented only in a few parts of the world, usually including mostly basal species within the group. The Cañadon Asfalto Formation is known for possessing one of the highest diverse microvertebrates association of South America, including also a large variety of small ornithischians. Several publications mentioned an isolated ornithopod ungual phalanx and the holotype of the species Manidens condorensis Pol et al., 2011 as representative specimens of the ornithischian diversity on the Cañadon Asfalto Formation, the last being also one of the most complete findings for the family in South America. In recent years, the fossil material of Jurassic ornithischians considerably grew, including not only isolated teeth material, but also isolated and associated corporeal elements. More specifically, were founded new fossil remains referable to Manidens condorensis (isolated teeth, a supposed maxilla, a dentary and an ilium), and new ornithischian remains (two new morphotypes of isolated teeth, one maxilla with isolated crowns morphologically similar, an incomplete specimen, two metatarsals with several phalanges and caudal vertebrae, one isolated sacrum and a fragmented ilium, and several isolated caudal vertebrae), that show a more abundant record than expected, and perhaps a more diverse small ornithischian fauna than previously thought. This communication aims to give a brief introduction to this ornithischian richness for the Early Jurassic of the Cañadon Asfalto Formation, including the importance of the group with respect to the diversity and size of preserved species.