Marta S. FernÃndez, Yanina Herrera, VerÃnica V. Vennari, Lisandro Campos, Marcelo de la Fuente, Marianella Talevi &Â Beatriz Aguirre-Urretad (2019)
Marine reptiles from the Jurassic/Cretaceous transition at the High Andes, Mendoza, Argentina.
Journal of South American Earth Sciences (advance online publication)
Highlights
The new localities of southern Mendoza have yielded abundant marine reptile remains.
Marine reptile remains are more abundant in the Corongoceras alternans ammonite Zone.
At Arroyo Durazno ichthyosaur records are abundant and metriorhynchids are common.
At Arroyo Paulino the records of ichthyosaurs and metriorhynchids are common.
One turtle and non plesiosauroids or pliosaurids were recorded.
Abstract
Upper Jurassic and Lower Cretaceous deposits of the Vaca Muerta Formation (NeuquÃn Basin, central-west Argentina) have yielded abundant marine reptile remains. Most of them correspond to faunal assemblages recovered from outcrops in the NeuquÃn Province (Argentina). Herein we report two new marine reptile-bearing localities documenting the TithonianâBerriasian transition at the High Andes (Mendoza Province, Argentina). Marine reptiles have been mapped and/or collected in connection with an accurate ammonoid-based biostratigraphic control. All the skeletons have been found preserved in, or associated with, calcareous nodules. At both localities they are frequent in beds assigned to the upper Tithonian Corongoceras alternans Ammonite Zone (Microcanthum to "Durangites" Standard Zones), and are rare to common in beds assigned to the upper Tithonianâlower Berriasian Substeueroceras koeneni Zone ("Durangites" to Jacobi Standard Zones). Newly discovered assemblages depict a similar pattern characterized by the lack of plesiosaurs (plesiosauroids and pliosaurids), and by the abundance of mesoconsumers represented by ophthalmosaurids and metriorhynchine metriorhynchids. Macropredator geosaurines, apex metriorhynchids predators, and thalassochelydian turtles are rare components of these assemblages.