Paleontologists from the New Mexico Museum of Natural History and Science, the University of Texas at El Paso and Montana State University discovered the fossil bones Tenontosaurus sp. – Early Cretaceous ornithopod dinosaur from North America – in the Yucca Formation in far western Texas, USA. This southernmost Tenontosaurus record in the interior West is approximately 400 km east of the Arizona record and approximately 900 km southwest of the north-central Texas record.
Life restoration Tenontosaurus tilletti. Image credit: Nobu Tamura, http://spinops.blogspot.com.
Tenontosaurus is a genus of iguanodontic ornithopod dinosaurs that lived in North America during the Early Cretaceous period, about 115 million years ago.
Two representatives of the genus are known: Tenontosaurus tilletti And Tenontosaurus bumps.
They had an unusually long and wide tail, which, like their back, was strengthened by a network of bone tendons.
New Tenontosaurus The fossils were collected from the Upper Yucca Formation in the Indio Mountains, approximately 35 km southwest of Van Horn, West Texas.
“I wasn't looking for a fossil that day,” he said. Dr. Jason Rickettspaleontologist from the University of Texas at El Paso.
“I was studying the rocks in the area when I noticed fragments of weathered soft shale.”
“There was no need to dig – I just picked them up. It was an unexpected and exciting find, and my family even came with me to help collect the pieces.”
“Finds of dinosaur fossils in West Texas are rare, and finding fossilized bones rather than just tracks is especially rare.”
“The fossils were found in individual fragments, the largest of which was identified as part of a femur.”
“Although the fossils are incomplete, they have significant scientific value,” he said.
“Prior to this discovery, the closest places where similar fossils had been found were Montana, Idaho, Arizona and other parts of Texas.”
This discovery expands the known range Tenontosaurus further southwest than previously recorded.
“Until now, fossils of this species have been known primarily from areas further north and east, such as Utah and Wyoming,” Dr. Ricketts said.
“This discovery shows that Tenontosaurus lived in the south, in West Texas.”
Although the fossil fragments are still being studied, the authors hope the discovery will inspire further research in West Texas, a region that remains underexplored for dinosaur fossils.
“This discovery shows there is still much to learn about our region's prehistoric past,” Dr Ricketts said.
“I’m honored to make even a small contribution to this big story.”
The discovery is reported in paper published in New Mexico Museum of Natural History and Science Bulletin.
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Spencer J. Lucas etc.. 2025. An ornithopod dinosaur from the Lower Cretaceous of West Texas. New Mexico Museum of Natural History and Science Bulletin 101:291-294
