Teeth fossils identify six non-avian dinosaurs of the Upper Cretaceous in Spain

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Teeth fossils identify six non-avian dinosaurs of the Upper Cretaceous in Spain
Artist's rendering of a small dromaeosaur from the South Pyrenees. (Illustration: Sydney Mohr)

Similar to the importance that teeth hold in forensic science, teeth fossils are highly regarded in paleontology. Using a set of such teeth fossils, researchers have managed to identify six non-avian dinosaurs of the Upper Cretaceous in Spain.

Researchers examined 142 isolated teeth – theropod teeth to be precise – to shed light on the evolution of dinosaurs at the end of the Cretaceous. The discovery of six additional species of toothed theropods (five small, one large) has effectively quadrupled the dinosaur diversity in the area of study, eight localities from Treviño County, Huesca and Lerida–including the exceptional site of Laño. There were previously only two known species in the area.

The samples were located in the Campanian-Maastrichtian of the South Pyrenean Basin. Lead author Angelica Torices, post-doctoral fellow in biological sciences at the University of Alberta say that using these teeth, they were able to “reconstruct the ancient world where dinosaurs lived and to understand how their extinction happened.”

One of the reasons why teeth are so important for research about dinosaurs of Upper Cretaceous is that in Spain and the rest of Europe there are no complete skeletons of theropods from that time in those locations. Because of the absence of other fossils, researchers have to rely on small elements to reconstruct the evolution of dinosaurs, particularly the theropods.

This study demonstrates the value of isolated teeth in reconstructing the composition of dinosaur paleofaunas when other, more complete material is not present, allowing interpretation of the evolution of diversity through time.

The findings provide huge strides in understanding not only the diversity of carnivorous dinosaurs at the end of the Cretaceous in Europe, but also how the diversity of large animals responds to climatic changes. “It completely changes the vision of the ecosystem,” says Torices. “Moreover, we now understand that these dinosaurs disappeared very quickly in geological time, probably in a catastrophic event. Climatic models show that we may reach Cretaceous temperatures within the next century, and the only way we can study biodiversity under such conditions is through the fossil record.”

Findings of the study have been published in journal Acta Palaeontologica Polonica.