A Mesalands Community College paleontology class has found a fossil that could be of a new form of Triassic reptile at an eastern New Mexico dig site.
“I think that we have found a new form of aetosaurs,” said Axel Hungerbuehler, professor of Paleontology at Mesalands Community College.
The aetosaur, or eagle lizard, fossils were among numerous fossils excavated at a site in the Redonda formation in Quay County.
Aetosaurs, a heavily armored plant-eater that lived in the Triassic period an estimated 200 Million years ago, are identified by the armor plating
on their back and sides. Each of the plates has a distinct pattern and shape, Hungerbuehler said.
“The analysis of the armor plates found at the dig site indicates that we have found a new form of aetosaur,” Hungerbuehler said.
In addition to the plates, they have identified bones of the internal skeleton of an aetosaur, including parts of the hip and several leg bones. So far, however, no complete articulated skeletons have been excavated from the site, Hungerbuehler said.
Several more dinosaur-like elements, including another hip bone (pubis) and several hollow limb bones, were also recovered, Hungerbuehler said.
“These bones are not from the same individual dinosaur that was found in 2007,” Hungerbuehler said. “They could be fossils of a similar type of dinosaur.”
In 2007 a field class found a hip bone (ilium) of an un-named primitive dinosaur that was collected at the Redonda Formation site.
“We have not done enough examination of the fossil to determine if it is a new and previously undiscovered type of primitive dinosaur,” Hungerbuehler said. “A definite identification will be done once these fossils have been freed from their rocky host and they can be carefully cleaned.”
This all started during the summer of 2006, when three field classes and several volunteers of Mesalands Community College’s Dinosaur Museum started excavating bones of reptiles at the current dig site.
Hungerbuehler said an abundance of fossils were found in red and green siltstones, and sandstones of the Upper Triassic estimated to be 200 million years old. To date, about 250 field numbers have been recorded.
Workers have gathered a wide range of assorted additional items including bags of weathered bone fragments, single bones, and plaster jackets of various sizes which include whole sections of sandstone with dozens of bones imbedded in the rocks, Hungerbuehler said.
It is estimated that close to one thousand skeletal elements have been recovered so far, including skulls, skull fragments, vertebrae, ribs, limb bones, body armor plates, and teeth.
With the prospects of having discovered new forms of animals that lived in the eastern New Mexico area millions of years ago, Hungerbuehler said his paleontology students at Mesalands are cautiously excited about their find.
“The site is rapidly developing into dimensions approaching the famous ‘quarries’ that have produced the majority of Triassic age fossil finds in the Southwest,” Hungerbuehler said. “Much like the classic Coelophysis quarry in the Chama basin, which yielded hundreds of remains of New Mexico’s state fossil, the early dinosaur Coelophysis.”
At the site they have found that bones occur in two different settings.
l In coarser layers of sandstones, bones are evenly distributed and show signs like breaking and abrasion, indicating they have been washed together by water currents.
l In red, fine-grained siltstones, undamaged bones have been found in spots of dense concentrations. These probably represent skeletons that fell apart at the spot.
Many of the bones still await preparation.
Items identified from the records kept in the field and the bones already freed from the rock in Mesalands Community College’s Dinosaur Museum Lab include:
l Phytosaurs — semiaquatic crocodile-like reptiles
Two phytosaur skulls and parts of a large lower jaw were recovered, plus numerous bones of the body.
l Large carnivorous reptile
A large reptile, perhaps, a rauisuchian (Rau’s crocodiles) which includes the largest predators in the Late Triassic, is represented by the tip of a lower jaw. The element is currently under study by students at Mesalands to confirm the identity