{"id":700922,"date":"2026-05-29T05:54:14","date_gmt":"2026-05-29T05:54:14","guid":{"rendered":"https:\/\/www.newsbeep.com\/ca\/700922\/"},"modified":"2026-05-29T05:54:14","modified_gmt":"2026-05-29T05:54:14","slug":"fearsome-dinosaur-era-marine-reptile-was-the-t-rex-of-the-sea","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/ca\/700922\/","title":{"rendered":"Fearsome dinosaur-era marine reptile was the T. rex of the sea"},"content":{"rendered":"

\n\tTEXAS: Tyrannosaurus rex was a huge land predator during the twilight of the age of dinosaurs. But it was not the only T. rex that terrorized the Cretaceous Period. There also was a marine reptile named Tylosaurus rex \u2014 the T. rex of the sea \u2014 that rivaled its land counterpart in size and ferocity.
Scientists said they have identified Tylosaurus rex as a distinct species after a wide-ranging examination of previously discovered fossils. They made the judgment based on its enormous size, fine serrations along the edges of its teeth to cut flesh more efficiently, heavy-duty musculature of the jaws and neck for subduing large prey, and certain other anatomical nuances.
Roughly 66 million years ago, Tyrannosaurus rex roamed the land in Western North America. Approximately 80 million years ago, Tylosaurus rex prowled an inland sea that at the time split North America in two. The seagoing T. rex \u200chad a streamlined body, \u200celongated snout with large teeth, four large paddle-like flippers and a powerful tail.
The genus \u200cTylosaurus \u2060has been known \u2060since fossils were first unearthed during the 19th century. A handful of species are recognized, including Tylosaurus proriger. A genus is a grouping of closely related species sharing similar characteristics. For example, lions and tigers are from the same genus but represent different species.
The largest Tyrannosaurus rex specimen, nicknamed Sue and held at the Field Museum in Chicago, is about 40-1\/2 feet long (12.3 meters).
The largest Tylosaurus rex specimen, nicknamed Bunker and held at the University of Kansas Biodiversity Institute and Natural History Museum, is about 43 feet (13.2 meters) long. Bunker previously had been identified as Tylosaurus proriger, but possessed the suite of traits that \u2060assigned it to Tylosaurus rex, the researchers said.
\u201cThe skull alone is as long \u200cas I am tall \u2014 5-foot-7 inches (1.7 meters),\u201d said paleontologist Amelia Zietlow \u200cof the History Museum at the Castle in Appleton, Wisconsin, lead author of the study published in the Bulletin of the American \u200cMuseum of Natural History.
Tylosaurus is a member of a group of marine reptiles with a global distribution called mosasaurs \u200cthat evolved from land-living lizards to become apex marine predators during the final roughly 30 million years of the age of dinosaurs. Today\u2019s monitor lizards including the Komodo dragon \u2014 the largest present-day lizard at up to 10 feet (3 meters) long \u2014 are perhaps among the closest living relatives of Tylosaurus rex.
\u201cI\u2019m impressed by modern Komodo dragons,\u201d Zietlow said. \u201cI can barely imagine what it would have been \u200clike to be near something many times bigger and even more hateful \u2014 said with love.\u201d
Study co-author Ron Tykoski, vice president of science and curator of vertebrate paleontology at \u2060the Perot Museum of Nature and \u2060Science in Dallas, said Tylosaurus rex would have been twice the length of today\u2019s largest great white sharks.
\u201cImagine standing, or more appropriately swimming, next to a 35 to 45 foot (10.7 to 13.7 meters) long marine Komodo dragon,\u201d Tykoski said. \u201cWould you say that would be pretty danged impressive?\u201c
Most of the fossils identified as Tylosaurus rex come from north and central Texas, though Bunker came from Kansas. The holotype specimen \u2014 the fossil used to formally name a species \u2014 is at the Perot Museum.
The new species name, meaning \u201cking of the tylosaurs,\u201d was a nod to Tyrannosaurus rex \u2014 \u201can incredible animal itself, obviously,\u201d Zietlow said.
These two T. rexes were not contemporaries, though forerunners of the giant dinosaur lived at the same time as the giant mosasaur. Tylosaurus rex was among the largest of the mosasaurs, alongside the likes of Mosasaurus hoffmanni.
While Tyrannosaurus rex could target the largest prey on land, Tylosaurus rex could do so in the sea.
\u201cStrong muscles and serrated teeth suggest that Tylosaurus rex was preying on other large animals, likely other marine reptiles and large fish, and ripping them to pieces. Tylosaurus species in general were not picky eaters \u2014 their teeth are not super specialized toward any one kind of prey besides \u2018other animals,\u2019\u201d Zietlow said.<\/p>\n","protected":false},"excerpt":{"rendered":"TEXAS: Tyrannosaurus rex was a huge land predator during the twilight of the age of dinosaurs. But it…\n","protected":false},"author":2,"featured_media":700923,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7],"tags":[49,48,66],"class_list":["post-700922","post","type-post","status-publish","format-standard","has-post-thumbnail","category-science","tag-ca","tag-canada","tag-science"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/posts\/700922","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/comments?post=700922"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/posts\/700922\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/media\/700923"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/media?parent=700922"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/categories?post=700922"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/tags?post=700922"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}