TITHONIAN MARINE REPTILES OF THE EASTERN PACIFIC

GASPARINI, Z. AND M. FERNÁNDEZ

ANCIENT MARINE REPTILES

Academic Press

Año: 1997; p. 435 - 450

Jurassic marine reptiles are found in South America only along the Pacific margin. The largest collection of these reptiles comes from the Tithonian of the Neuqu6n Basin (Argentina). Analysis of this fauna indicates some biogeographic trends: (1) turtles (Notoemys, Neusticemys)are endemic at familial and generic levels; (2) crocodiles (Geosaurus, Metriorhynchus, Dakosaurus), plesiosaurs (Liopleurodon, Pliosaurus), and ichthyosaurs (Ophthalmosaurus) are the same genera recorded in the West Tethys. We propose that during the Late Jurassic, and probably before, during the Middle Jurassic, exchange events between reptiles from the Andean region and the West Tethys were favored by the opening of the Hispanic Corridor. Callovian crocodiles in Chile and southwestern Mexico, Callovian plesiosaurs (cf. Muraenosaurus; cf. Cryptoclidus) in the Neuqu6n Basin, and Oxfordian plesiosaurs and crocodiles in Cuba support this hypothesis. The invertebrate fauna also supports this idea. The links to the Tethyan fauna could also be favored during the Late Jurassic by the opening of a new seaway between South America---Africa and Antarctica. The discovery of ichthyosaur remains and fishes from the Upper Jurassic outcrops in the northeast of the Antarctic Peninsula is the first evidence of marine vertebrates in this seaway.