\n <\/p>\n
This artistic interpretation shows a pack of Nanotyrannus attacking a juvenile Tyrannosaurus rex (front left).<\/span>Credit: Anthony Hutchings<\/span><\/p>\n A fossil once assumed to be of a young Tyrannosaurus rex is in fact that of a different species altogether, and the dinosaur it belongs to was a fully grown adult at the time of its death, palaeontologists have found.<\/p>\n Facelift for T. rex: analysis suggests teeth were covered by thin lips<\/p>\n<\/p>\n The small tyrannosaur \u2014 named Nanotyrannus \u2014 is about half the length and one-tenth of the body mass of a fully grown T. rex \u2014 which led scientists to initially suspect the fossil belonged to a teenage T. rex. But the specimen has several distinct physical features, too.<\/p>\n \u201cNanotyrannus is a small-bodied predator designed for speed. It\u2019s very agile and has long powerful arms [that are] larger than those of the T. rex,\u201d says Lindsay Zanno, a palaeontologist at North Carolina State University in Raleigh. Nanotyrannus also had a shorter tail than did T. rex and sharper, less curved teeth.<\/p>\n The findings, published in Nature on 30 October1, come from the \u2018Duelling Dinosaurs\u2019 fossils \u2014 a Triceratops and a small tyrannosaur found tangled in combat in the Hell Creek Formation in Montana in 2006. The specimens date back to the latest Cretaceous period, around 67 million years ago.<\/p>\n To determine the Nanotyrannus\u2019s age and growth rate, Zanno and her colleague James Napoli, a palaeontologist at Stony Brook University in New York, studied the growth rings present in a thin slice of one of the fossilized bones. These marks show how bone growth has slowed down and sped up with the seasons, creating layers like a tree trunk\u2019s annual rings. The researchers compared the dinosaur\u2019s growth rate with that of a crocodile, one of its closest living relatives.<\/p>\n","protected":false},"excerpt":{"rendered":" This artistic interpretation shows a pack of Nanotyrannus attacking a juvenile Tyrannosaurus rex (front left).Credit: Anthony Hutchings A fossil once assumed to be of a young Tyrannosaurus rex is in fact that of a different species altogether, and the dinosaur it belongs to was a fully grown adult at the time of its death, palaeontologists<\/p>\n","protected":false},"author":1,"featured_media":31697,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[58],"tags":[5237,16489,5004,5228],"class_list":{"0":"post-31696","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-science","8":"tag-fossil","9":"tag-rex","10":"tag-species","11":"tag-teenage"},"_links":{"self":[{"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=\/wp\/v2\/posts\/31696","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=31696"}],"version-history":[{"count":0,"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=\/wp\/v2\/posts\/31696\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=\/wp\/v2\/media\/31697"}],"wp:attachment":[{"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=31696"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=31696"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=31696"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}Small but ferocious<\/h2>\n