Scientists have identified a giant new species of mosasaur, a marine reptile that lived alongside dinosaurs and dominated prehistoric oceans. The newly described hunter, named tylosaurus rex (Or T. rex), measured up to 43 feet long and is one of the largest mosasaurs ever discovered.
The research was led by scientists from the American Museum of Natural History, the Perot Museum of Nature and Science in Dallas, and Southern Methodist University. Fossils of the giant reptile were found primarily in North Texas and are approximately 80 million years old.
“Everything is bigger in Texas, and that clearly includes mosasaurs,” said Amelia Zietlow, lead author of the study published in. Bulletin of the American Museum of Natural History.
Zietlow, now at the History Museum in Cassel, Wisconsin, began examining the fossils while working as a Ph.D. Comparative Biology student in the Richard Gilder Graduate School of the American Museum of Natural History. His research began when he noticed that a fossil in a museum’s collection had been incorrectly identified as another species, Tylosaurus prorigor.
Fossils reveal a different and more powerful mosasaur
After comparing the sample with the original T. prorigor After the fossil was housed in Harvard University’s Museum of Comparative Zoology, researchers realized that the Texas fossils represented a different species entirely. More than a dozen similar fossils stored in museums were eventually linked to the newly identified predator.
The team found several differences between the two species. The new mosasaur was larger, had finely serrated teeth rarely seen in mosasaurs, and came from a different place and time period. most of T. prorigor The fossils have been found in Kansas and date back to about 84 million years ago, while the new species lived primarily in what is now Texas about 80 million years ago.
Researchers chose the name tylosaurus rex As a tribute to paleontologist John Thurmond. In the late 1960s, Thurmond recognized that the giant tylosaurs from northeast Texas appeared unusually large and probably belonged to a separate species. He informally called them “Tylosaurus thalassotyrannus,” meaning “sea tyrant.”
Holotype specimen for T. Rex Currently on display at the Perot Museum in Dallas. The fossil was originally discovered in 1979 near an artificial reservoir outside the city.
Evidence suggests violent fighting between marine predators
Researchers believe that beyond its enormous size tylosaurus rex Built for strength and aggression. This species had adaptations involving particularly powerful jaws and neck muscles, making it a formidable hunter.
“In addition to being huge, almost twice the length of the largest great white shark, T. Rex “It appears to be a much meaner animal than other mosasaurs,” said study co-author Ron Tykosky, vice president of science and curator of vertebrate paleontology at the Perot Museum. tylosaurus Samples.”
Scientists point to a famous specimen nicknamed “The Black Knight” as evidence of this predatory behavior. The fossil housed in the Perot Museum is missing the tip of its snout and appears to have a broken lower jaw. Researchers say the injuries were likely caused by another member of the same species.
Other famous mosasaur fossils previously identified T. prorigor now being reassigned T. Rex. These include “Bunker”, a giant fossil on display at the University of Kansas, and “Sophie”, which is on display at the Yale Peabody Museum.
Discovery challenges long-held ideas about mosasaur evolution
The study also tackles a major issue in mosasaur research. The scientists noted that the main dataset used to study evolutionary relationships among mosasaurs has changed little over the past three decades.
To address this, the team created a revised dataset and developed a new evolutionary framework for tylosaurs. Their findings suggest that many previous studies may need to be revisited.
“This discovery is not just about naming a new species,” Zietlow said. “This highlights the need to revisit long-held assumptions about mosasaur evolution and modernize the tools we use to study these iconic marine reptiles.”
Co-author Michael Polsin of Southern Methodist University said the discovery expands understanding of both the animals themselves and the ancient ecosystems they live in.
“These findings reshape both the physical and evolutionary picture of mosasaurs, highlighting Texas as a key region for understanding ancient marine ecosystems and signaling a new era of research into the evolutionary history of these formidable predators.”
Support for the research came from the National Science Foundation, the Dallas Paleontological Society, the Society of Systematic Biologists, the Richard Gilder Graduate School, the Gingrich Fund, and the Carter Fund.