Fossils originally discovered in New Mexico seven years ago have been identified as the bones of an extinct reptile that lived during the Upper Triassic and was related to crocodiles, according to a new study published earlier this week in the open-access journal PeerJ.
The newly identified species was discovered during a 2009 expedition at Ghost Ranch, a retreat and educational center in the north-central part of the state. That expedition was led by Sterling Nesbitt, a postdoctoral researcher at the University of Texas at Austin at that time and currently an assistant professor of geosciences at the Virginia Tech College of Science.
Nesbitt and his colleagues recovered jawbones, skull fragments, hip bones, and other fossils of the creature, but many of those remains were sealed in protective plaster jackets until two years ago, when they were analyzed by undergraduate researcher Emily Lessner and her colleagues.
They discovered that the bones belonged to an extinct rauisuchid that lived during the Norian stage of the Upper Triassic, approximately 212 million years ago. The creature has been named Vivaron haydeni in honor of a legendary 30-foot-snake spoken of in Ghost Ranch campfire tales more than a century ago, and John Hayden, the hiker who in 2002 first discovered the quarry in which the creature’s remains were discovered.
Creature’s jaw bone is was sets it apart, study authors note
Lessner, who studying in both the geosciences and biological sciences departments at Virginia Tech as a sophomore at the time she first encountered the bones, and her colleagues, explained in a statement that she jumped at the chance to work with Nesbitt upon his arrival to the Blacksburg university – originally by cleaning bones and performing CT scans on fossils.
Ultimately, however, her work with the professor led to the identification of just the sixth species of rauisuchid ever discovered, and only the sixth found in what is currently the southwestern US but was at one time the western part of the supercontinent Pangea. Vivaron likely measured 12 to 18 feet long, walked on four legs and was a meat eater, according to the study authors.
The new species is said to be distinguishable by its upper jaw bone, which looks much smoother than the other rauisuchid species discovered to date. The researchers have found three jaw bones, skull fragments and hip bones from at least three different individuals, one of which was smaller than the others, and they believe that the site may contain yet-undiscovered Vivaron remains.
“It is possible that other bones were not preserved, were previously collected, or are still in the ground,” Lessner explained. She added that her undergraduate research experience, which now includes being published in a journal by the age of 22, “has given me opportunities that simply attending class never has and has opened up doors for my future. I have been able to gain first-hand experience in the field.”
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Image credit: Matt Celeskey
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