Toronto, Aug 7 (IANS): After studying 142 isolated teeth from the South Pyrenean Basin in Spain, researchers have discovered six new species of toothed carnivorous dinosaurs (theropods) in the region.

These teeth (five small, one large) belong to non-avian dinosaurs who lived in the Upper Cretaceous region 165 million years ago and throw a fresh light on how dinosaurs went extinct.

"Studying these small parts helps us reconstruct the ancient world where dinosaurs lived and to understand how their extinction happened,” said lead author Angelica Torices, post-doctoral fellow in biological sciences at the University of Alberta in Canada.

Theropods first appeared 231 million years ago and included the sole large terrestrial carnivores from the Early Jurassic until at least the close of the Cretaceous period.
Birds evolved from small specialised theropods and are today represented by 10,000 living species.

Teeth are especially important in the study of Upper Cretaceous creatures in Spain and the rest of Europe because paleontologists do not have complete skeletons of theropods from that time in those locations.

"We have to rely on these small elements to reconstruct the evolution of these dinosaurs, particularly the theropods,” Torices added.

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,” Torices noted.

Moreover, we now understand that these dinosaurs disappeared very quickly in geological time, probably in a catastrophic event, the study said.

"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,” the authors contended in the paper published in the journal Acta Palaeontologica Polonica.