The Latest Cretaceous fauna with dinosaurs and mammals from the Haţeg Basin — A historical overview

Research on the uppermost Cretaceous continental deposits with dinosaur remains from the Haţeg Basin has behind it a history of more than 110 years. The first studies were by Franz Nopcsa (1877–1933) who published between 1897 and 1929 a series of notes and papers on this fauna, including five monographs dedicated to the Haţeg dinosaurs. Nopcsa described 10 vertebrate taxa, including dinosaurs, crocodilians and turtles, from the Haţeg Basin, out of which 6 are still valid. He recognized the primitiveness and the small size of most of the taxa from the Haţeg palaeofauna, characters that he related to the isolated island environment within which this fauna lived for a long time span.After Nopcsa, systematic research on the Haţeg fauna was interrupted for many decades, being resumed after 1977 when D. Grigorescu, leading a small group of students in Geology started to explore the deposits outcropping along the Sibişel valley, near Sânpetru village, from where Nopcsa made most of his collection of fossil bones. Since then the fieldwork continued every summer until now, numerous remains of dinosaurs, crocodiles and turtles being unearthed. The list of the Maastrichtian fauna from Haţeg currently includes 56 taxa from all vertebrate classes. More than half of the recorded taxa were discovered in micropalaeontological samples through screen-washing. The most spectacular discoveries made after 1977 include a large variety of small theropods, several sites with dinosaur egg clutches, one of these also yielding hatchling remains, one of the largest pterosaurs in the world, representing a new genus and species, Hatzegopteryx thambema, and several taxa of multituberculate mammals.Studies of the Haţeg fauna were not restricted to systematic palaeontology, but also covered all the fields that contribute together to an accurate reconstruction of the environment within which the Maastrichtian fauna existed. This overview includes a list of contributors to the actual knowledge on the Haţeg fauna, during the last 30 years, divided by fields of scientific interest.