Researchers have identified a new species of mosasaur, a giant marine reptile that lived 80 million years ago, based on fossils found in North Texas. Named Tylosaurus rex—dubbed the 'T. rex of the sea'—this predator reached lengths roughly double that of the largest great white sharks. The discovery was led by Amelia Zietlow, whose analysis of a misidentified fossil in a museum collection revealed unique traits, including finely serrated teeth and robust jaw muscles. The holotype specimen, discovered near Lake Ray Hubbard in 1979, is now on display at the Perot Museum of Nature and Science.

The species shows evidence of intra-species violence, with one specimen—nicknamed The Black Knight—bearing a fractured jaw and missing snout tip, likely from combat with another of its kind. These findings not only confirm a new apex predator but also reshape understanding of mosasaur evolution. The study, published in the Bulletin of the American Museum of Natural History, highlights Texas as a crucial region for uncovering ancient marine ecosystems.

The research underscores the importance of museum collections and citizen science, as many fossils were found and preserved by amateur fossil hunters. Dr. Michael Polcyn of Southern Methodist University notes this work signals a new era in studying these formidable sea creatures. With its powerful build and aggressive features, Tylosaurus rex emerges as one of the most dominant marine predators of its time.