Paleontologists have unearthed a surprising discovery in West Texas, pushing back the known range of the Tenontosaurus, an Early Cretaceous herbivorous dinosaur that roamed North America approximately 115 million years ago. The fossils, found in the Yucca Formation of the Indio Mountains, mark a significant southward expansion for this particular species compared to previous finds concentrated further north and east.
This discovery is particularly noteworthy because Tenontosaurus remains relatively rare in the fossil record, with just two known species: Tenontosaurus tilletti and Tenontosaurus dossi. These dinosaurs were identifiable by their unusually long, stiff tails supported by a network of bony tendons. They shared this unique feature with their relatives on land—the iguanodontians, another group of herbivorous dinosaurs.
What makes this find even more intriguing is its geographic location. The new fossils are situated approximately 35 kilometers southwest of Van Horn, Texas, and an astonishing 400 kilometers east of any previously discovered Tenontosaurus remains in Arizona. This pushes the southernmost boundary for these dinosaurs back by a substantial distance.
The discovery was made unexpectedly by Dr. Jason Ricketts from the University of Texas at El Paso while studying rocks in the area. While not actively fossil hunting, he noticed fragments weathering out of shale and immediately recognized their potential significance.
“It was an unexpected and exciting find,” Dr. Ricketts stated. “Dinosaur fossils are rare finds in West Texas; to uncover fossilized bones instead of just footprints is exceptionally uncommon.”
While the recovered remains were fragmented—with the largest piece identified as part of a femur—they hold substantial scientific value. The pieces, according to Dr. Ricketts, “although incomplete, have significant scientific value” because they significantly broaden our understanding of this dinosaur’s distribution. He emphasizes that previous fossil records primarily placed Tenontosaurus in Utah and Wyoming, making these West Texas findings a major revelation.
This discovery serves as a potent reminder that the geological tapestry of North America holds many untold stories about its prehistoric inhabitants. It highlights how much remains unknown about even relatively well-studied dinosaurs like the Tenontosaurus. Dr. Ricketts hopes this find will spark further exploration in West Texas, urging us to delve deeper into the region’s largely unexplored past for more dinosaur secrets.
“This discovery shows that there’s still much to learn about our region’s prehistoric past,” he said. “It’s a privilege to contribute even a small piece to that bigger story.”
The study detailing this significant find was published in the NM Museum of Natural History and Science Bulletin.
