Titanosaurs are a group of sauropod dinosaurs (characterized by a small head, long neck and tail, and columnar legs similar to those of an elephant). They are the last group known to have inhabited Europe during the Late Cretaceous, the final period before the dinosaur extinction 66 million years ago, and include the largest known dinosaurs, such as Patagotitan mayorum, the largest land animal that has ever existed. 

Now, a research team from the Institut Català de Paleontologia Miquel Crusafont (ICP) has published a study on the most complete dentition in Europe attributed to a single individual of these latter giants. The discovery was made at the Els Nerets site (Vilamitjana, Pallars Jussà), one of the most important locations in the Conca de Tremp with an age of around 70 million years. The teeth were not in their anatomical position but were found disarticulated. Nevertheless, being scattered around a titanosaur skull, researchers think that they belong to the same animal. 

This is a collection of 18 teeth with slender, conical crowns, displaying a marked development of the mesial and distal carinae – the sharp ridges running along the side of the tooth, akin to the blade of a spear. Although they're designed to cut plant matter like pruning shears, they are more blunt than those of carnivorous dinosaurs. On top of that, the characteristics and shape of the teeth suggest that the dinosaur they come from, doesn't resemble any of the titanosaur species found in Europe, but they exhibit the features of teeth from this group. 

When the teeth were compared among themselves, researchers have discovered something unusual. While typically, the teeth of the mouth of the same dinosaur tend to look quite similar (in comparison to our own, for example), in this case, differences in shape have been observed. 'Since they all belong to the same individual, we believe that the differences between teeth are due to the position they occupied in the mouth, as happens with mammals, which can have teeth with a variety of shapes, such as incisors or molars,' explains Bernat Vázquez, a paleontologist from the Dinosaur Ecosystems Research Group at the ICP and the first author of the published article. 'However, in this case the differences are not as extreme, as all the teeth serve the same function,' concludes the researcher.

Image 1. Life appearance of a titanosaur and landscape recreation of the Pyrenees during the Upper Cretaceous (Oscar Sanisidro / © Institut Català de Paleontologia Miquel Crusafont.

The research has led to the development of a method to determine the position in the mouth of any isolated titanosaur tooth found in the field. This represents a significant advancement, as loose teeth were previously considered to provide little information and were often not considered beyond merely descriptive aspects. By applying this method, researchers have been able to reconstruct the position of the discovered teeth, thus obtaining a substantial portion of the original dental configuration of the animal for future studies. 

Although everything indicates that the teeth belong to a new species unknown to science, certainty cannot be achieved until the skull and other elements of the skeleton found in the same site are studied. 

Bernat Vázquez and Bernat Vila, co-authors of the research, are paleontologists from the ICP and the Museu de la Conca Dellà. The team also includes Diego Castanera, a researcher from Fundación Conjunto Paleontológico of Teruel-Dinópolis. The research has been published in the international journal Cretaceous Research. 

The dinosaurs of the Pyrenees, the last ones in Europe. 

The discovery is another example of the exceptional dinosaur fossil record in Catalonia. In the various Pyrenees sites, there are evidences of the last dinosaurs that lived in Europe, just a few million and even thousands of years before their extinction across the planet. These fossils represent the primary field of study for paleontologists and serve as an endless source of content for interpretation centers and museums in the area, promoting a unique paleontological heritage. The interest in Pyrenean dinosaurs lies in them being the last recorded dinosaur groups in Europe, providing significant information about the ecosystems before the mass extinction at the end of the Cretaceous period.

Main image: Image of one of the teeth of the titanosaur that has been included in the study. The length is about 3 cm (Bernat Vázquez / © Institut Català de Paleontologia Miquel Crusafont).

Original article:  

• Vázquez, B.-J., Castanera, D., & Vila, B. (2023, published online). Titanosaurian teeth from the South-central Pyrenees (Upper Cretaceous, Catalonia, Spain). Cretaceous Research. https://doi.org/10.1016/j.cretres.2023.105753