Jurassic marine reptiles of the neuquen Basin: recods, faunas and their paleobiogeographic significance

GASPARINI, Z. AND M. FERNÁNDEZ

The Neuquen Basin, Argentina: A case Study in Sequence Stratigraphy and Basin Dynamics

The Geological Society

Lugar: Londres; Año: 2005; p. 279 - 294

The largest diversity of Jurassic marine reptiles of the Gondwana has been recorded in the Neuquén Basin. Despite the Early Jurassic records are scanty, those of the Middle Jurassic, especially early Bajocian plesiosaurs and ichthyosaurs are unique as there are no records of this age in other parts of the world. The highest abundance and taxonomic diversity is recorded at the Late Jurassic (Tithonian). Pleurodiran (Notoemys) and cryptodiran turtles (Neusticemys), ichthyosaurs (Ophthalmosaurus, Caypullisaurus), pliosaurs (Pliosaurus, Liopleurodon) and crocodiles (Geosaurus, Metriorhynchus, Dakosaurus) are members of this rich marine herpetofauna. Except for Notoemys, the other reptiles are pelagic. Their habits and large size (Caypullisaurus, Liopleurodon, Dakosaurus) suggest that they entered the basin occasionally possibly for reproduction in protected areas. The model of a basin open to the Pacific Ocean, protected by island arches, is the best one to explain the ecological requirements inferred for most of the pelagic reptiles. The Caribbean Corridor may have played a main role as a seaway at least during the Middle Jurassic and probably before. New findings in Tithonian and Berriasian sediments of the Neuquén basin, suggest that there was no massive extinction among the marine herpetofauna in the Jurassic-Cretaceous boundary