Prehistoric amphibian with a big bite gets a new name

group of animals.

It was named by Spencer G. Lucas, chief science officer of the New Mexico Museum of Natural History; Larry F. Rinehart, a recently retired museum employee who is now a volunteer research associate there; and Rainer R. Schoch of the State Museum of Natural History in Stuttgart, Germany.

The name and the species became official this week with the publication of an article by Rinehart, Lucas and Schoch in the Journal of Vertebrate Paleontology.

“This is not an earth-shaking find in the history of science, but for people in paleontology it’s a big deal,” Rinehart said during a phone interview Tuesday. “For a paleontologist, it doesn’t get much better than finding and naming a new species.”

A field party from the Museum of Northern Arizona, a natural history museum in Flagstaff, found the bone bed encrusted with the fossils of the new species in the 1980s. Schoch of the Stuttgart museum dug at the site in 2000 or 2001.

But most of the fossil extraction, supervised by Rinehart, was done by the New Mexico Museum of Natural History in 2010, 2011 and 2012. The bones are now part of the museum’s permanent collection.

“Most of that work was done by volunteers,” Rinehart said. “We never had more than four or five people working there at a time, but over two or three years there were 15 or 20 people involved. Some were students who have since become employees of the museum. Some were just retired people looking for something interesting to do.”

Eocyclotosaurus appetolatus dates back to the Triassic period. Its alligator-like head had hundreds of teeth in addition to the two large fangs that protruded upward from its lower jaw and through holes in front of the creature’s nostrils. It had small limbs but a wide tail that aided it in swimming.

During the animal’s heyday, the area that is now New Mexico was crisscrossed by large rivers that flowed toward a seacoast near what is now the Utah-Nevada border. Eocyclotosaurus appetolatus ate fish and seized prey along river banks and lake shores.

Rinehart said physical evidence, the shape of the jaws and teeth, suggest the creature caught its victims with a swift, sideways snap of its head. That’s what led to its name — from the Latin words appetere, which means to grab or attack, and latus, which means to the side.

Temnospondyl is the name of the larger group to which the new species belongs. Scientists have known about Temnospondyl since the late 19th century.

The genus Eocyclotosaurus, a close cousin of the new species, has been known since 1970 and its fossils have been found in Arizona and Europe — especially in Germany.

What distinguishes the new species from its relatives, Rinehart said, is the shape of its skull, the position and size of its eyes and bigger fangs, 2 inches long.

Another thing that distinguishes the new species is the number of bones found. Often, the fossils of related creatures discovered earlier were limited to skulls and jaws. But fossils found in the Pecos River valley site include every bone of Eocyclotosaurus appetolatus, and that helps scientists understand what the creature looked like — and more.

“Many bone samples help to find how fast the thing grew, at what age it matured, what it was capable of doing,” Rinehart said.

He estimates that a mature animal would weigh more than 100 pounds and that the bigger it got, the less capable it would be of getting around on land.

“It could walk on land when young,” Rinehart said. “But I have studied the growth of the leg bones and what happens is that as the animal grows larger, its weight increases rapidly but the strength of its bones does not. As it gets bigger, it’s not going to be scampering around in the woods.”