Remains of a new species of dinosaur found in Coahuila

Saltillo, Coah., The Coahuila Desert once again offered a key piece to understand the evolution of dinosaurs in North America. Mexican and foreign paleontologists presented the discovery of Xenovenator espinosaia new genus and species of feathered carnivorous dinosaur that inhabited the region approximately 74 million years ago, during the late Cretaceous.

The discovery, unveiled at the Desert Museum and published in the international scientific journal Diversityis based on the study of an exceptionally well-preserved endocranium, located in the Cerro del Pueblo formation, in the southeast of the state. The species was named in honor of Luis Espinosa, a pioneer in the study of dinosaurs in Mexico.

Xenovenator espinosai It belonged to the group of troodontids, small and medium-sized theropod dinosaurs, with a relatively large brain in proportion to its body and a close evolutionary relationship with the origin of birds. According to researchers, it reached up to three meters in length, was a nocturnal hunter and fed on small vertebrates, including primitive mammals. The size and orientation of its eyes, as well as its serrated dentition, point to a highly specialized predator.

For specialists, the discovery is not an isolated event. It is part of a sequence of findings that, for just over two decades, transformed Coahuila into the main paleontological reference in Mexico. Starting in 2000, municipalities such as General Cepeda, Ocampo, Sabinas and Múzquiz began to reveal fossil wealth that changed the narrative about the north of the country.

The breaking point was Velafrons coahuilensisa herbivorous dinosaur with a unique cranial crest that placed Coahuila in the international scientific discussion. They were followed by emblematic species such as Coahuilaceratops bighornwith large frontal horns; Yehuecauhceratops changedanother endemic ceratopsid; and the so-called Sabinas sabinosaurus, one of the most complete hadrosaur skeletons recovered in Mexico.

In recent years, the emergence of predators such as Paraxenisaurus normalensiswith Asian affinities, and Mexidracon longimanusidentified by its unusually long forelimbs, reinforced the idea that northern Mexico was a center of biological diversification and not a peripheral region.

Added to this set are fossil footprints, pterosaurs such as Muzquizopteryx coahuilensis and marine remains that allowed the reconstruction of ancient rivers, plains and inland seas that covered part of the current Coahuila territory.

In that context, Xenovenator espinosai provides a new key to understanding how late Cretaceous ecosystems were structured. The Coahuila desert, far from being an empty space, preserves beneath its surface the memory of a complex world that is just beginning to reveal itself.

The dinosaurs of Coahuila continue to tell a story that is only beginning to be understood.

Some of the main paleontological finds in Coahuila from 2000 to 2025 include the following: from 2000 to 2003, the recovery of articulated hadrosaurs and associated fauna from the late Cretaceous; from 2005 to 2006 Sabine Sabinosaurus and the Hadrosaurio with about 80 percent of the skeleton preserved; from 2012 to 2014 the Muzquizopteryx coahuilensishe Pterosaurio found in Múzquiz and the expansion of the record of flying reptiles in Mexico; from 2021 to 2022 Coahuilasaurus lipani (taxonomic redefinition), Hadrosaurio recognized after reclassifying old materials; and in 2025 the Mexidracon longimanustheropod dinosaur with very elongated forelimbs.

The most recent discovery confirms Coahuila as a center of endemic diversity, among them.