The discovery nearly two decades ago of nine beautifully articulated vertebrae at Big Bend National Park is shedding new light on a 66 million-year-old sauropod native to Texas and the North American southwest called Alamosaurus sanjuanensis.
Paleontologists from the Perot Museum of Nature and Science in Dallas have co-authored a scientific paper entitled “An articulated cervical series of Alamosaurus sanjuanensis Gilmore, 1922 (Dinosauria, Sauropoda) from Texas: new perspective on the relationships of North America’s last giant sauropod.” Their findings are now available online as an open access article at the Journal of Systematic Palaeontology website and will appear in its forthcoming January/February 2017 print edition. The lead author is Ronald S. Tykoski, Ph.D., the Perot Museum’s Director of Paleontology Lab, and the co-author is Anthony R. Fiorillo, Ph.D., the Perot Museum’s Chief Curator and Vice President of Research and Collections.
“Giant sauropods like Alamosaurus have amazed people since the 1800s. Their sheer size boggles the mind, and they have forced scientists to re-think the physical limits of land-living animals,” said Tykoski. “The fossils described in our paper reveal new details about the last sauropods in North America, which helps us better understand who Alamosaurus was related to and how this species made it to southern North America by 67 to 66 million years ago — just in time to go extinct at the end of the Cretaceous!”
The name Alamosaurus came from the Ojo Alamo trading post and geological formation in New Mexico from which the first bones of the species were found (not after the historic battle in San Antonio, Texas in 1836). The name of the trading post stemmed from the Spanish word for a huge cottonwood tree growing at the trading post. Alamosaurus was a titanosaur sauropod, one of the groups of long-necked and long-tailed dinosaurs that included the largest animals to walk the Earth.
The discovery of the massive bones came in 1997 when a joint field crew from the University of Texas at Dallas (UT-D) and the Perot Museum (known at that time as the Dallas Museum of Natural History) was working in the northeast section of Big Bend National Park. The scientists and volunteers were excavating a site that produced parts of several immature sauropods when Dana Biasatti, then a student at UT-D, “stretched her legs” and came upon the remarkable remains of an adult titanosaur a few hundred yards away. The team was stunned. The nine cervical (neck) vertebrae were the first articulated series of adult Alamosaurus neck bones ever found. The fossils of Alamosaurusfrom Big Bend National Park currently represent the biggest dinosaurs discovered in Texas.
“It was one of those days one doesn’t ever forget. The part of the animal that was exposed at the surface was the hip region. Probing around the site resulted in the discovery of this incredible neck,” said Fiorillo. “One of the intriguing aspects of this project is that for us to better understand this dinosaur in our home state, we had to also rely, in part, on the results of the scientific work the Perot Museum has been doing in Arctic Alaska over the same window of time.”