Gordodon’s name might evoke a certain girth, but this newly discovered reptile from about 300 million years ago was a vegan weighing in at a mere 75 pounds — a lightweight compared to the mighty dinosaurs that came later.
The 2013 find in Southern New Mexico of a fossilized partial skeleton of this sail-backed, 5-foot-long creature, announced Wednesday by the New Mexico Museum of Natural History and Science, is forcing experts to rethink the evolution of scaly plant-eaters.
The fossil was found in March 2013 near Alamogordo by Ethan Schuth, who was on a field trip with a geology class from the University of Oklahoma. Field crews from the natural history museum in Albuquerque collected the fossilized bones and carefully removed the sandstone that covered them.
The gordodon is now displayed in the museum’s atrium. Its incomplete skeleton consists of the skull, lower jaws and all or parts of 21 vertebrae.
“This is one of the most remarkable discoveries I have been a part of,” museum paleontologist Spencer Lucas said.
The primitive herbivore walked the planet about 75 million years before dinosaurs, he said.
The gordodon had a specialized jaw and teeth with a gap in them, Lucas said. “Animals that have that gap today are selective feeders,” munching on particular types of vegetation.
“Previously, the oldest known animals with teeth as specialized as gordodon were found in rocks no older than 205 million years ago,” Lucas said.
“We don’t know very much about plant eating by reptiles,” he added. The discovery means “we are going to have to rethink what we thought we knew about how early reptiles became herbivores.”
It’s still not known exactly what was in the gordodon’s diet, he said. The reptile might have had fermented vegetation in its stomach, similar to how cows process food.
In order to find out what the gordodon feasted on, Lucas said, a fossil would have to show the animal’s abdomen.
In a news release announcing the fossil, the Museum of Natural History and Science said the reptile is a new genus and species of eupelycosaur, a group of animals that thrived during the Permian Period.
Eupelycosaurs include the ancestors of mammals, making them more closely related to humans than to dinosaurs, the museum said.
The news of the gordodon find was announced first in the journal Palaeontologia Electronica, a publication of the Paleontological Society, in a peer-reviewed article by Lucas and museum associates Larry Rinehart, a retired fossil preparer, and researcher and artist Matt Celeskey.
Lucas and his co-workers named the reptile Gordodon kraineri.
The genus name comes from the Spanish gordo, “fat,” and the Greek odon, “tooth,” a reference to the large pointed teeth at the tips of the animal’s jaws, according to the museum’s news release. It is also a reference to Alamogordo, where the fossil was found.
The species name, kraineri, honors Austrian geologist Karl Krainer, for his work in New Mexico.
Along with gordodon’s unusual teeth, the low “sail” on its back has intrigued scientists.
“It has a totally different kind of sail” than other reptiles, Lucas said, adding that he and his colleagues believe the sail might have acted as a radiator to cool the animal and “probably functioned as a signaling device.”
“These fossils will change our minds about what we think we know,” Lucas said. “… There must be more out there.”