A surprising fossil discovery in the desert of West Texas has revealed that a dinosaur species once thought to roam only the northern parts of North America also lived much farther south.
The finding, made by Dr. Jason W. Ricketts, a geologist and associate professor at the University of Texas at El Paso (UTEP), could reshape scientists’ understanding of how dinosaurs spread across the continent during the Early Cretaceous period, about 115 million years ago.
Ricketts wasn’t searching for fossils when he stumbled upon the discovery.
He was studying rock formations at UTEP’s Indio Mountains Research Station (IMRS)—a 41,000-acre natural field laboratory located about 26 miles southwest of Van Horn, Texas—when he noticed fragments of bone weathering out of a layer of soft shale.
“I wasn’t out looking for fossils that day,” Ricketts said. “I was studying the rocks when I noticed fragments on the surface.
There was no need to dig—I simply picked them up. It was an unexpected and exciting find, and my family even came out to help collect the pieces.”
The fossils were later identified as belonging to Tenontosaurus, a medium-sized, plant-eating dinosaur that lived during the Early Cretaceous period.
Ricketts described the discovery in a paper titled “An Ornithopod Dinosaur from the Lower Cretaceous of West Texas,” published by the New Mexico Museum of Natural History and Science.
He coauthored the study with Dr. Spencer G. Lucas, a paleontology curator at the museum, and Sebastian G. Dalman, a doctoral student at Montana State University.
Dinosaur fossils are rare in West Texas, and finding actual bones—rather than just tracks—is even more unusual.
The bones were found as separate fragments, with the largest identified as part of a femur, or leg bone. Though incomplete, the fossils are scientifically valuable because they extend the known range of Tenontosaurus farther southwest than ever before.
“Until now, fossils of this species were known mainly from Utah, Wyoming, and other regions farther north and east,” Ricketts explained. “This discovery shows that Tenontosaurus lived as far south as West Texas.”
Tenontosaurus was a four-legged herbivore that could also walk on two legs, feeding on ferns and other low-growing plants. The discovery site provides fresh evidence about how these dinosaurs moved across ancient landscapes and adapted to different environments in North America.
Dr. Liz Walsh, interim dean of UTEP’s College of Science, praised the find as a testament to the power of curiosity-driven research. “This discovery shows the importance of fieldwork and reminds us that major scientific insights often come when we least expect them,” she said.
For Ricketts, the find is both thrilling and humbling. “It shows there’s still so much to learn about our region’s prehistoric past,” he said. “It’s a privilege to contribute even a small piece to the story of life on Earth.”
