A new species of herbivorous dinosaur has been discovered in Utah and sheds light on the major environmental changes that occurred in North America about 100 million years ago. The name of the dinosaur is Iani smithi.

This dinosaur may be one of the last of its kind at a time when Earth’s warmer climate forced massive changes in dinosaur populations worldwide. The transition between the Early and Late Cretaceous periods saw a major reorganization of global ecosystems associated with a peak in global temperatures.

The increase in carbon dioxide in the atmosphere caused temperatures to rise and sea levels to rise, causing dinosaurs to be concentrated in ever smaller areas.

The fossils were located in Utah’s Cedar Mountain Formation and include a well-preserved skull and parts of the spine and limbs. The name given to the dinosaur comes from the Roman god Janus, who was the god of transitions and so the name of the dinosaur refers to the changing world of the mid-Cretaceous Period.

This is the first early ornithopod known from the Late Cretaceous of North America. Ornithopod dinosaurs are a group of mainly bipedal herbivores, including Iguanodon, Parasaurolophus and Tenontosaurus.

“We knew such a species lived in this ecosystem because individual teeth had been collected but we didn’t expect to come across such a beautiful skeleton, especially from this time in Earth’s history. Having a nearly complete skull was invaluable in piecing together the story,” says Lindsey Zano, an associate professor at North Carolina State University, head of paleontology at the North Carolina Museum of Natural Sciences, and an author of the study. The study was published in the open access journal Plos One.

This discovery, along with other recent reports from the same geological formation, show that several large groups of dinosaurs survived into the early Late Cretaceous period despite the environmental changes of the time, but it is unclear how long they lasted. Of course, this particular dinosaur belongs to the early rhabdomorphs, a lineage of ornithopods known almost exclusively from Europe, and this raises questions.