Calvarius rapidus

The new species Calvarius rapidus belongs to the ornithopods, one of the most diverse groups of herbivorous dinosaurs, which includes iguanodons and platypus hadrosaurs. rapidus inhabited the territory of the modern Catalan Pyrenees at the end of the Cretaceous period, about 66 million years ago.

It is believed that this geological era ended with the collision of the Earth with an asteroid, resulting in the extinction of all flightless dinosaurs and many other living organisms.

It is the chronological closeness of the mass extinction that gives the new species the name Calvarius – the Catalan word calvari means “to suffer.” Rapidus means “fast” in Latin.

The fossil remains collected are limited to a small bone taken from the left leg, which is very well preserved. This material was excavated in 2019 at the Macia de Ramón site in the Catalan province of Lleida, which paleontologists became aware of in 2001.

Bone of Calvarius rapidus / Photo by ICP

Scientists say they have discovered features of this dinosaur that are both similar and very different from its close relatives, suggesting that it is a new species. This C. rapidus individual was not sexually mature at the time of death, but was close to skeletal maturity. He was probably 8-10 years old. The species was a fast runner no longer than 2 meters tall, making it one of the smallest of the bunch.

The geological interpretation of the strata in which C. rapidus was found indicates that it died near a meandering river surrounded by abundant bush vegetation and ferns. The climate in these places at the end of the Cretaceous period was warmer and wetter than today, and resembled the climate of subtropical regions with prolonged periods of drought and heavy rain. In addition to C. rapidus, remains of small vertebrates such as crocodiles, fish and lizards have been found here.