{"id":799870,"date":"2026-05-16T05:28:15","date_gmt":"2026-05-16T05:28:15","guid":{"rendered":"https:\/\/www.europesays.com\/us\/799870\/"},"modified":"2026-05-16T05:28:15","modified_gmt":"2026-05-16T05:28:15","slug":"giant-tyrannosaur-fossil-found-in-new-mexico","status":"publish","type":"post","link":"https:\/\/www.europesays.com\/us\/799870\/","title":{"rendered":"Giant Tyrannosaur Fossil Found in New Mexico"},"content":{"rendered":"

A large tyrannosaurid dinosaur may have stalked the floodplains of what is now New Mexico nearly 74 million years ago, according to a team of paleontologists from the University of Bath, Montana State University and the New Mexico Museum of Natural History and Science.<\/strong><\/p>\n

\"Bistahieversor<\/a><\/p>\n

Bistahieversor sealeyi hunting Pentaceratops sternbergii. Image credit: A. Belov \/ CC BY 3.0.<\/p>\n

\u201cThe Tyrannosauridae were among the last and the largest of the predatory dinosaurs,\u201d lead author Dr. Nicholas Longrich from the University of Bath and his colleagues wrote in their paper.<\/p>\n

\u201cFollowing the extinction of the carcharodontosaurs in the mid-Cretaceous, tyrannosaurs diversified and evolved large size, becoming the dominant predators of the latest Cretaceous in both North America and Asia.\u201d<\/p>\n

\u201cBy the Late Campanian, multiple groups of tyrannosaurids, including Albertosaurinae, Daspletosaurini, and Teratophonei, had achieved large sizes of 2-3 tons.\u201d<\/p>\n

\u201cTheir evolution culminated in the appearance of the giant Tyrannosaurus, both one of the last tyrannosaurids and the largest tyrannosaurid, and perhaps the largest known predatory dinosaur ever to evolve.\u201d<\/p>\n

In their study, the paleontologists examined an unusually large tyrannosaur tibia (shinbone) from the Hunter Wash Member of the Kirtland Formation, New Mexico.<\/p>\n

The specimen measures 96 cm in length and 12.8 cm in diameter, about 84% and 78% the dimensions of the largest known Tyrannosaurus.<\/p>\n

Based on comparisons with known tyrannosaur species, the researchers estimated the animal weighed roughly 4 to 5 tons.<\/p>\n

\u201cThis represents the oldest known giant tyrannosaur from North America and may represent the oldest known member of the Tyrannosaurini<\/a>,\u201d they wrote in the paper.<\/p>\n

The tibia shares several features with later tyrannosaurs, especially Tyrannosaurus rex.<\/p>\n

The scientists considered three possibilities: that the fossil belonged to an unusually large individual of the previously-known New Mexican tyrannosaur Bistahieversor sealeyi<\/a>; that it represented a previously unknown lineage of giant tyrannosaurs; or that it was an early member of the group Tyrannosaurini, which includes Tyrannosaurus rex and its Asian relatives.<\/p>\n

After comparing the fossil with other tyrannosaurs and conducting a phylogenetic analysis, the authors concluded that the third explanation was the most likely.<\/p>\n

\u201cRegardless of which hypothesis is adopted, the unusual size of the Hunter Wash tyrannosaur is significant, as it represents a previously unrecognized appearance of large tyrannosaurids in the Late Campanian, and shows that they evolved earlier than previously believed,\u201d they wrote.<\/p>\n

For decades, paleontologists have debated where giant tyrannosaurs first evolved.<\/p>\n

Some have argued that the lineage originated in Asia before dispersing into North America.<\/p>\n

Others have proposed that giant tyrannosaurs emerged in the southern portion of the western North American landmass known as Laramidia.<\/p>\n

The newly-described fossil strengthens the southern-Laramidian-origin hypothesis.<\/p>\n

\u201cThe Hunter Wash tyrannosaur emphasizes the marked endemicity of Laramidian dinosaurs; while smaller Albertosaurinae and Daspletosaurini inhabited the north, giant tyrannosaurins occurred in the south,\u201d the paleontologists concluded.<\/p>\n

The team\u2019s paper<\/a> was published in March 2026 in the journal Scientific Reports.<\/p>\n

_____<\/p>\n

N.R. Longrich et al. 2026. A large tyrannosaurid from the Late Cretaceous (Campanian) of North America. Sci Rep 16, 8371; doi: 10.1038\/s41598-026-38600-w<\/p>\n","protected":false},"excerpt":{"rendered":"A large tyrannosaurid dinosaur may have stalked the floodplains of what is now New Mexico nearly 74 million…\n","protected":false},"author":3,"featured_media":799871,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":"","_share_on_mastodon":"0"},"categories":[8],"tags":[325933,325934,16277,43603,43606,325935,325936,325937,11198,587,159,325938,325939,325940,325941,325942,113031,67,132,68],"class_list":["post-799870","post","type-post","status-publish","format-standard","has-post-thumbnail","category-science","tag-bistahieversor","tag-bistahieversor-sealeyi","tag-cretaceous","tag-dinosaur","tag-fossil","tag-hunter-wash","tag-kirtland-formation","tag-laramidia","tag-new-mexico","tag-north-america","tag-science","tag-tibia","tag-tyrannosaur","tag-tyrannosauridae","tag-tyrannosaurini","tag-tyrannosaurus","tag-tyrannosaurus-rex","tag-united-states","tag-unitedstates","tag-us"],"share_on_mastodon":{"url":"https:\/\/pubeurope.com\/@us\/116582607871673117","error":""},"_links":{"self":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/posts\/799870","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/comments?post=799870"}],"version-history":[{"count":0,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/posts\/799870\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/media\/799871"}],"wp:attachment":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/media?parent=799870"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/categories?post=799870"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/tags?post=799870"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}