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New species identified: Not a Tyrannosaurus rex, or even a dinosaur, but a secret third thing

Tylosaurus Rex on display at the Perot Museum of Nature and Science in Dallas
Perot Museum of Nature and Science
Tylosaurus Rex on display at the Perot Museum of Nature and Science in Dallas

Millions of years ago — Texas was just the bottom of the sea. Huge marine reptiles swam the depths, but these dinosaur-looking creatures are not called dinosaurs, they're mosasaurs.

The Perot Museum of Nature and Science in Dallas has just determined that one of their resident mosasaur skeletons came from its own distinct species, named Tylosaurus rex.

Not to be mistaken for the Tyrannosaurus rex, this T. Rex is described as an "orca-sized Komodo dragon" by Vice President of Science and Curator of Vertebrate Paleontology at the Perot Museum, Dr. Ron Tykoski.

Artistic reconstruction of Tylosaurus rex in the Late Cretaceous Western Interior Seaway of North America.
/ Alderon Games - Path of Titans
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Alderon Games - Path of Titans
Artistic reconstruction of Tylosaurus rex in the Late Cretaceous Western Interior Seaway of North America.

Recent scientific discoveries have differentiated this Tylosaurus rex skeleton from the species it was originally thought to be. This specific skeleton, which hangs proudly on the fourth floor of the Perot, is approximately 36 feet long, and was found in 1979 on the shores of Lake Ray Hubbard.

Thanks to Dr. Tykoski and Dr. Amelia Zietlow at the American Museum examining differences in this skeleton, such as large muscle attachments on the skull and extra bumps on the jaw, is what differentiated this species from a more generic classification.

Dr. Amelia Zietlow examines the Tylosaurus rex holotype skeleton in February 2023.
/ Perot Museum of Nature and Science
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Perot Museum of Nature and Science
Dr. Amelia Zietlow examines the Tylosaurus rex holotype skeleton in February 2023.

Dr. Tykoski says it is his life's work to interpret and reconstruct life in the distant past. But, getting the picture exactly right isn't necessarily the goal for paleontologists.

"Undoubtedly, I am getting almost all of it wrong because all I have to work with are bones, or shells, or things like that," he said. "There's so much about these organisms that we'll never know about, because we can't see a living, breathing one. We do the best we can with the evidence with which we're presented and try to reconstruct that ancient world so we can understand how life has been in the past."

Partial upper and lower jaws of Tylosaurus rex specimen
/ Perot Museum of Nature and Science
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Perot Museum of Nature and Science
Partial upper and lower jaws of Tylosaurus rex specimen

Paleontologists understand that we won't ever know the whole story when it comes to life millions of years ago. Only a small fragment of organisms are preserved in fossil history, and Dr. Tykoski says trying to understand the past is can help us understand the future.

"It's all part of this thread of life. And it just happens I look way backwards to look at mine to try to figure out where we're going way forward," Dr. Tykoski said.

Miranda Suarez is a co-host of KERA's NTX Now. Got a tip? Email Miranda at msuarez@kera.org.

KERA News is made possible through the generosity of our members. If you find this reporting valuable, consider making a tax-deductible gift today. Thank you.

Copyright 2026 KERA News

Miranda Suarez
Miranda Suarez is KERA’s Fort Worth reporter.