Paleontologists from the New Mexico Museum of Natural History and Science, the University of Texas at El Paso and Montana State University have actually found the fossil bones of Tenontosaurus sp.– an Early Cretaceous ornithopod dinosaur from North America– in the Yucca Formation in far West Texas, the United States. This southernmost record of a tenontosaur in the Western Interior has to do with 400 km east of Arizona records and about 900 km southwest of its records in north-central Texas.

Tenontosaurus is a genus of iguanodontian ornithopod dinosaurs that resided in North America throughout the Early Cretaceous, around 115 million years earlier.

2 members of the genus are understood: Tenontosaurus tilletti and Tenontosaurus dossi

They had an uncommonly long, broad tail, which like its back was stiffened with a network of bony tendons.

The brand-new Tenontosaurus fossils were gathered from the Upper Yucca Formation in the Indio Mountains, roughly 35 km southwest of Van Horn, West Texas.

“I wasn’t out trying to find fossils that day,” stated Dr. Jason Ricketts, a paleontologist at the University of Texas at El Paso.

“I was studying the rocks in the location when I discovered pieces weathering out of soft shale.”

“There was no requirement to excavate– I just chose them up. It was an unanticipated and amazing discover, and my household even brought out me to assist gather the pieces.”

“Dinosaur fossil discoveries in West Texas are unusual, and the finding of fossilized bones, instead of simply footprints, is particularly unusual.”

“The fossils were discovered as private pieces, with the biggest recognized as part of a thigh leg bone.”

“Although insufficient, the fossils have considerable clinical worth,” he stated.

“Before this discovery, the nearby locations where comparable fossils had actually been discovered were Montana, Idaho, Arizona, and other parts of Texas.”

This discovery extends the recognized variety of Tenontosaurus further southwest than formerly recorded.

“Until now, fossils of this types were understood mostly from regions further north and east, such as Utah and Wyoming,” Dr. Ricketts stated.

“This finding reveals that Tenontosaurus lived as far south as West Texas.”

While the fossil pieces are still being studied, the authors hope the discovery will influence additional expedition in West Texas, an area that stays mostly underexplored for dinosaur fossils.

“This discovery reveals that there’s still much to discover our area’s ancient past,” Dr. Ricketts stated.

“It’s an opportunity to contribute even a little piece to that larger story.”

The discovery is reported in a paper released in the NM Museum of Natural History and Science Bulletin

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Spencer G. Lucas et al2025. An ornithopod dinosaur from the Lower Cretaceous of West Texas. NM Museum of Natural History and Science Bulletin 101: 291-294