A newly discovered armoured dinosaur from New Mexico is closely related to those found in Alberta, according to a University of Alberta study.
Paleontologists said that Alberta was home to at least five species of ankylosaurid dinosaurs from 76 to 66 million years ago including club-tailed giants like Ankylosaurus. Few other ankylosaurids are believed to have roamed the southern parts of North America.
Ziapelta sanjuanensis, one of the newly discovered species of ankylosaurid dinosaurs, was discovered in 2011 in the Bisti/De-na-zin Wilderness area of New Mexico by New Mexico Museum of Natural History and Science and the State Museum of Pennsylvania.
"Bob Sullivan, who discovered the specimen, showed us pictures, and we were really excited by both its familiarity and its distinctiveness-we were pretty sure right away we were dealing with a new species that was closely related to the ankylosaurs we find in Alberta," said U of A PhD graduate Victoria Arbour, in a press release.
Ziapelta differs from other ankylosaurs due to its oddly tall spikes on the cervical half ring, a structure that bears a resemblance to a yoke of bone sitting over the neck. The new species' skull also distinguishes it from other known ankylosaurs.
"The horns on the back of the skull are thick and curve downwards, and the snout has a mixture of flat and bumpy scales-an unusual feature for an ankylosaurid," said Arbour. "There's also a distinctive large triangular scale on the snout, where many other ankylosaurids have a hexagonal scale."
Ziapelta belongs to the Late Cretaceous period, when a vast inland sea divided North America in two.
"The rocks in New Mexico fill in this gap in time, and that's where Ziapelta occurs," said Arbour. "Could Ziapelta have lived in Alberta, in the gap where we haven't found any ankylosaur fossils yet? It's possible, but in recent years there has also been increasing evidence that the dinosaurs from the southern part of North America-New Mexico, Texas, and Utah, for example-are distinct from their northern neighbours in Alberta."
The finding is published in the journal PLOS ONE.
