April Flowers for redOrbit.com – Your Universe Online
What do New Mexico and Alberta, Canada, have in common? Perhaps not much today, but millions of years ago they were both inhabited by closely related species of ankylosaurid dinosaurs, according to a study from the University of Alberta, New Mexico Museum of Natural History and the State Museum of Pennsylvania. The findings, published in PLOS ONE, describe a newly discovered species of armored dinosaur found in the Bisti/De-Na-Zin Wilderness area of New Mexico.
Alberta was home to at least five different ankylosaurid dinosaur species between 76 and 66 million years ago. This group of dinosaurs includes the club-tailed giants like Ankylosaurus. In the southern parts of the continent, however, very few ankylosaurids are known. A team of scientists from the New Mexico Museum of Natural History and Science and the State Museum of Pennsylvania discovered the new species, Ziapelta sanjuanensis, in 2011. The Bisti / De-Na-Zin Wilderness, where the fossils were found, is a Bureau of Land Management (BLM) facility comprised of over 41,000 acres of badlands south of Farmington, NM. In Navajo, Bisti means “a large area of shale hills,” while De-Na-Zin takes its name from the word for “cranes.”
A group of researchers from the University of Alberta, including recent PhD graduate Victoria Arbour and current doctoral student Michael Burns, were invited to participate in the project because of their expertise in the diversity of ankylosaurs from Alberta.
Image Above: University of Alberta researchers Michael Burns and Victoria Arbour display a fossil from a newly discovered armored dinosaur called Ziapelta sanjuanensis. Credit: University of Alberta
“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,” Arbour said.
Ziapelta sanjuanensis is different from other ankylosaurs because of the unusually tall spikes found on the cervical half ring. The half ring is a bony structure, much like a yoke, sitting over the neck. The animal’s skull is also different from others of its species.
“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,” notes Arbour. “There’s also a distinctive large triangular scale on the snout, where many other ankylosaurids have a hexagonal scale.”
Ziapelta roamed North America during the Late Cretaceous. During this time, known as the end of the age of dinosaurs, a vast inland sea divided North America and both Alberta and New Mexico had beachfront property. Fossils from ankylosaurs have been found in several of the rocky formations of southern Alberta, but so far, none in the lower part of an area called the Horseshoe Canyon Formation.
“The rocks in New Mexico fill in this gap in time, and that’s where Ziapelta occurs,” says 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 neighbors in Alberta.”
Arbour says that they will be on the lookout for Ziapelta in the Horseshoe Canyon Formation in the future.
New Species Of Armored Dinosaur Found In New Mexico
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