The discovery of dinosaurs extends the known range of ancient species

The discovery of a dinosaur fossil by a researcher at the University of Texas at El Paso may expand the known range of the species that roamed the Earth about 115 million years ago.

Jason W. Ricketts, Ph.D., associate professor in UTEP’s Department of Earth, Environmental and Resource Sciences, discovered the fossils—belonging to the dinosaur Tenontosaurus—while conducting unrelated fieldwork at the Indio Mountains Research Station (IMRS), a 41,000-acre natural laboratory run by UTEP. Horn, Texas.

“I wasn’t looking for fossils that day,” Ricketts said. “I was studying the rocks in the area when I noticed that the pieces outside of soft shale didn’t require weathering.

Ricketts details the discovery in a paper titled “An Ornithopod Dinosaur from the Lower Cretaceous of West Texas,” recently published by the New Mexico Museum of Natural History and Science. Spencer G. Lucas, PhD, curator of paleontology at the museum, and Sebastian G. Dalman, a doctoral student at Montana State University, collaborated with the study.

Dinosaur fossil discoveries are rare in West Texas, Ricketts said, and finding fossilized bones rather than just footprints is particularly unusual. The fossils were found as individual fragments, the largest of which was identified as part of a femur leg bone. Although incomplete, the fossil has significant scientific value, he said. Before this discovery, the closest places where similar fossils were found were Montana, Idaho, Arizona and other parts of Texas.

“This discovery extends the known range of Tentosaurus far beyond what was previously documented in the Southwest,” Ricketts explained. “Until now, fossils of this species were known primarily from areas further north and east, such as Utah and Wyoming. This discovery suggests that Tenontosaurus lived as far south as West Texas.”

Tenontosaurus was a medium-sized, plant-eating dinosaur that lived during the Early Cretaceous period. The discovery site adds an important piece to the puzzle of how these dinosaurs dispersed across North America and adapted to diverse environments, the team said.

Liz Walsh, interim dean of the UTEP College of Science, hailed the discovery as an example of how curiosity-driven research can lead to great insights.

“This highlights the importance of fieldwork and the role of dedicated researchers like Dr. Ricketts in uncovering new chapters in Earth’s history,” Walsh said. “It’s also a reminder that great discoveries can happen when we least expect them.”

Although the fossil fragments are still being studied, Ricketts hopes the discovery will encourage further exploration in West Texas, a region not largely lacking in dinosaur fossils.

“This discovery shows that there is still much to learn about our region’s ancient past,” he said. “It’s an honor to contribute even a small piece to this larger story.”