First mentioned by F. Nopcsa, Hat¸eg Island was a paleogeographical concept sketched by this famous paleontologist in order to explain the presence of small-sized dinosaurs in uppermost Cretaceous localities from Transylvania (western Romania), and particularly from the Hateg Basin. However, this insularity is still debated, even after more than a century of research. In order to reconstruct the precise paleogeography of this area by Maastrichtian time, it is important to study all the coeval uppermost Cretaceous continental deposits from Transylvania. The westernmost region where these formations are exposed is the Rusca Montana˘ Basin (western Romanian Carpathians). The geological history of this sedimentary basin appears similar to that of the Hat¸eg Basin. We report the first Maastrichtian vertebrates from the Rusca Montana˘ Basin. These fossils include dinosaurs (ornithopod, sauropod, theropods), turtles (?Kallokibotion), indeterminate crocodiles, and multituberculate mammals (Kogaionidae). This fauna closely resembles that from the Hat¸eg Basin and is the first evidence of their presence to the west of Hateg.

Peer Review

Paleontology