CONICET | Buscador de Institutos y Recursos Humanos

Fieldworks carried out at the Pilmatué site, 9 km north of Las Lajas, Neuquén, have yielded remains of at least four dinosaur clades, which include dicraeosaurid and titanosauriform sauropods, basal tetanuran theropods and iguanodontian ornithopods. The specimens are distributed in at least two different levels of massive sandstones of the Mulichinco Formation (Valanginian). The specimens include partial articulated and disarticulated skeletons, which are well preserved and have no indications of significant transport prior to burial. The dicraeosaurid specimens are represented by adult individuals slightly smaller than Amargasaurus cazaui Salgado and Bonaparte. The titanosauriform specimens include heavily eroded axial and appendicular elements of a non-lithostrotian taxon. A complete, articulated hind limb of an ornithopod shows affinities with basal hadrosauriforms. A second specimen, presumably of the same form, which includes pelvic elements was recently collected and waits for preparation. A partially articulated, still unidentified tetanuran specimen preserves skull elements, a partial cervical and dorsal series of vertebrae, and isolated caudal vertebrae and elements of the pelvis. This locality has revealed a wealth of dinosaur remains from the Valanginian, which is a period of time with an extremely poorly known dinosaur diversity worldwide. In contrast to other Valanginian localities, the site of Pilmatué has well preserved, articulated to partially articulated specimens. Further fieldwork in this and surrounding areas will provide a unique opportunity to unveil the composition of a dinosaur fauna in the dawn of the Cretaceous in South America.