Museum discovers new predator that lived 210 million years ago

The new species was named Eosphorosuchus lacrimosa. It was described by palaeontologists at Yale University in a study published in Proceedings of the Royal Society B: Biological Sciences.

Details

The fossils come from the famous Ghost Ranch locality in New Mexico. The area is known for its large number of Late Triassic fossils, including dinosaurs, fish, lizard relatives and early crocodylomorphs - a group that includes modern crocodiles, alligators, caimans and their extinct relatives.

For a long time, the animal found was thought to be a member of the already known species Hesperosuchus agilis. But in a new study using computer tomography researchers were able to digitally "disassemble" the fossil bone by bone and see the differences.

The main difference is the structure of the head. Eosphorosuchus lacrimosa had a shorter snout, a strengthened skull and signs of developed jaw muscles. This suggests specialisation for a strong bite. Such a predator could probably attack larger or less mobile prey than its long-faced relative.

That said, it was neither a giant crocodile nor a dinosaur. The animal was about the size of a jackal or large dog and probably lived on land. In the Late Triassic, early crocodile relatives looked very different from modern semi-aquatic crocodiles: many were fast terrestrial predators.

Why it matters

The finding shows that early relatives of crocodiles occupied different ecological roles as early as 210 million years ago. Another crocodylomorph, Hesperosuchus agilis, was found next to Eosphorosuchus lacrimosa. They were similar in size but differed in head structure and probably diet.

This means that ecological specialisation in the crocodilian lineage began very early. Some species may have been faster hunters with a long snout, while others may have been predators with a short reinforced skull and a more powerful bite.

History also shows the value of museum collections. The fossil has been in the Yale Museum's collection for about 75 years, but new imaging techniques have made it possible to see things in it that previously went unnoticed.

Background

The Late Triassic was a time when different groups of reptiles competed for ecological dominance. The lineage leading to modern crocodiles and the dinosaur lineage already existed side by side. Meanwhile, early dinosaurs back then were often relatively small and slender, while some crocodile relatives were fast and strongly built land predators.

The researchers believe that the two Ghost Ranch animals could have died almost simultaneously, perhaps during a sudden natural event such as a flood or mudflow. This has given palaeontologists a rare "snapshot" of an ancient ecosystem where closely related species lived side by side but probably hunted differently.

Source

The study by Miranda Margulis-Ohnuma and co-authors A short-snouted "sphenosuchian" with unusual feeding anatomy demonstrates that ecological specialisation occurred early in crocodylomorph evolution published in Proceedings of the Royal Society B: Biological Sciences in 2026. The discovery was also reported by Yale University.