Scientists have identified a giant new species of mosasaurus, a marine reptile that lived alongside dinosaurs and dominated the prehistoric seas. The newly described predator is Tylosaurus rex (or tyrannosaurus), with a body length of up to 43 feet, making it one of the largest mosasaurs ever discovered.
The study was led by scientists from the American Museum of Natural History, the Perot Museum of Natural Science in Dallas, and Southern Methodist University. Fossils of giant reptiles are found primarily in northern Texas and date back about 80 million years.
“Everything seems to be bigger in Texas, and that includes mosasaurs.” Bulletin of the American Museum of Natural History.
Zietlow, now at the History Museum in Castle, Wisconsin, began studying fossils while working on his doctoral program. student studying comparative biology at the American Museum of Natural History’s Richard Gilder Graduate School. Her research began after she noticed that one of the fossils in the museum’s collection appeared to be incorrectly identified as a different species. Tylosaurus proliger.
Fossils reveal another, more powerful mosasaurus
After comparing the specimen with the original, T. Proliger While the fossil was in the Harvard Museum of Comparative Zoology, researchers realized that the Texas fossil represented an entirely different species. More than a dozen similar fossils kept in museums were eventually linked to the newly identified predator.
The research team found several differences between the two species. The new mosasaurs were larger, had finely serrated teeth rarely seen in mosasaurs, and came from a different place and time. largely T. Proliger The fossil was discovered in Kansas and dates to about 84 million years ago, but the new species lived primarily in what is now Texas about 80 million years ago.
Researchers decided on the name Tylosaurus rex As a tribute to paleontologist John Thurmond. In the late 1960s, Thurmond noticed that the giant tylosaurus in northeast Texas appeared unusually large and may have belonged to a different species. He informally called them “.”Tylosaurus Thalassotyrannusmeaning “tyrant of the sea.”
holotype specimen of tyrannosaurus It is currently on display at the Perot Museum in Dallas. The fossil was originally discovered in 1979 near an artificial reservoir on the outskirts of the city.
Evidence suggests fierce battles between marine predators
Beyond its gigantic size, researchers believe Tylosaurus rex Built for strength and aggression. This species has adaptations related to particularly strong jaw and neck muscles, making it a formidable hunter.
“In addition to being huge, about twice as long as the largest great white shark, tyrannosaurus “It appears to have been a much meaner animal than other mosasaurs,” said study co-author Ron Tycosky, vice president of science and curator of vertebrate paleontology at the Perot Museum. “Through study and testing of well-preserved fossils collected across north Texas, we now have evidence of this kind of violence never before seen in other mosasaurs.” Tylosaurus Specimen. ”
Scientists point to a famous specimen nicknamed “The Black Knight” as evidence of this violent behavior. The fossil, housed at the Perot Museum, is missing the tip of its nose and shows a fractured lower jaw. Researchers say the injury was most likely caused by another individual of the same species.
Other famous mosasaurus fossils previously identified T. Proliger is currently being reassigned to tyrannosaurus. These include the giant fossil “Bunker” on display at the University of Kansas and “Sophie” on display at Yale University’s Peabody Museum.
Discovery challenges long-held ideas about mosasaurus evolution
The study also addresses key questions in mosasaurus research. The scientists noted that the primary dataset used to study evolutionary relationships among mosasaurs has changed little over the past 30 years.
To address this, the team created a revised dataset and developed a new evolutionary framework for Tylosaurus. Their findings suggest that much of the previous research may need to be revisited.
“This discovery doesn’t just mean naming a new species,” Zietlow said. “This highlights the need to rethink long-standing assumptions about mosasaurus evolution and modernize the tools we use to study these iconic marine reptiles.”
Co-author Michael Polcyn of Southern Methodist University said the discovery expands our understanding of both the animals themselves and the ancient ecosystems in which they lived.
“These discoveries reconstruct both the physical and evolutionary context of mosasaurs, highlight Texas as a key region for understanding ancient marine ecosystems, and signal the beginning of a new era of research on the evolutionary history of these formidable predators.”
Support for this research was provided in part by the National Science Foundation, the Dallas Paleontological Society, the Society of Systematic Biologists, the Richard Gilder Graduate School, the Gingrich Endowment, and the Carter Endowment.
