This new troodontid dinosaur ( Troodontidae ), which lived 66 million years ago at the end of the Cretaceous period baptized as Tamarro insperatus, lived on what is known as the Ibero-Armoric island during the last Maastrichtian age of the Cretaceous period, some 200,000 years earlier. of the mass extinction of the end Cretaceous.
“During the late Cretaceous (77-66 million years ago) in the run-up to the late Cretaceous mass extinction, Europe was a series of islands populated by diverse and distinctive communities of dinosaurs and other vertebrates,” says Albert Sellés, paleontologist from the Institut Català de Paleontologia Miquel Crusafon of the Autonomous University of Barcelona and the Museu de la Conca Dellà. “Many of these animals exhibited peculiar characteristics that may have been generated by the lack of space and resources in their island habitats.”
These theropod dinosaurs, with great resemblance to our current birds , would have had specimens the size of a kiwi (less than 1 kg) to species the size of a rhea (about 50 kg in weight).
“The presence of troodontids in Europe has been debated for a long time, mainly because their registration was based entirely on isolated teeth, until now,” the researchers clarify in their study published in the journal Scientific Reports . “The oldest troodontid evidence in Europe dates back to the Early Cenomanian era (100-94 million years ago) and is based on the discovery of an isolated tooth in western France.”
It is one of the last dinosaurs to live in the Pyrenees . It was covered in feathers, had small or medium-sized wings and a long tail that would probably help them as a rudder to direct the flight, although they would have been gliders rather than flyers.
“The discovery of Tamarro insperatus in the last Maastrichtian deposits in the southern Pyrenees represents the first unequivocal bone evidence of this group of small non-avian theropods in Europe, and confirms the presence of troodontids in the theropod fauna of that continent. ”.
The isolated 66-million-year-old Tamarro insperatus bone was discovered in September 2003 by a team of paleontologists from the Museu de la Conca Dellà at the Sant Romà d’Abella site in Catalonia, Spain. “Its unique combination of anatomical characters allows it to be identified as a new species,” the experts said. “Furthermore, its histology shows a growth pattern in which it grew rapidly in early ontogeny, but reached sub-adult size quickly.”
This carnivorous dinosaur must have been between 1.5 and 2 meters long and would weigh about 20 kilograms. Their diet would have been based on small animals or even carrion, with a feeding pattern very similar to other carnivorous dinosaurs of similar size, such as eagles or hawks do, grabbing the meat and pulling it off forcefully.
According to the authors, Tamarro insperatus appeared within the faunal replacement of the Iberian-Armorian island at the beginning of the Maastrichtian era, which helps to define the origins and times of the migratory waves that brought the newcomers to the European archipelago. “We presume that it could have emigrated from Asia to reach the Iberian-Armorian island at the latest in the Cenomanian or during the Maastrichtian dispersal events,” they conclude.
Referencia: A.G. Sellés et al. 2021. A fast-growing basal troodontid (Dinosauria: Theropoda) from the latest Cretaceous of Europe. Sci Rep 11, 4855; doi: 10.1038/s41598-021-83745-5
