A formerly unknown relative of the most iconic of all dinosaurs, Tyrannosaurus rex, has been newly identified, according to a study released Thursday. The revelation adds a new clue that could help paleontologists unravel another step in the evolutionary chain that ended with the massive predatory tyrannosaur, T. rex. <\/p>\n
Called Tyrannosaurus mcraeensis, the creature likely roamed Earth up to 7 million years before T. rex emerged. The bones have been dated to 72 million to 73 million years old during the late Campanian-early Maastrichtian Period. <\/p>\n
But Tyrannosaurus mcraeensis\u2019 bones were discovered decades before the creature officially got its scientific name. About one-quarter of its fossilized skull was found over the course of the 1980s and early \u201990s in an area now known as Elephant Butte, New Mexico. Because of the size of the specimens, the bones were originally categorized by the New Mexico Museum of Natural History & Science as T. rex, which grew up to 39 feet (12 meters) long and 10 tons in weight. <\/p>\n
There were two big differences between T. rex and T. mcraeensis. <\/p>\n
\u201cThe lower jaw in a Tyrannosaurus rex is actually quite robust. Our jaw is obviously big and toothy, but it\u2019s more slender than what we normally see in a Tyrannosaurus rex,\u201d said Anthony R. Fiorillo, coauthor of the study published Thursday in the journal Scientific Reports. The robust jaw of T. rex meant it \u201ccould do whatever it wanted. A more slender jaw, even with the big teeth, means that it would have less bite force.\u201d <\/p>\n
The other big difference was that, unlike T. rex, T. mcraeensis didn\u2019t have a prominent ridge over its eyes. Scientists believe T. rex\u2019s ridge was used to help attract mates, much like antlers on deer or elk, said Fiorillo, who is executive director of the New Mexico Museum of Natural History & Science in Albuquerque. In T. mcraeensis, the ridge is much more subtle. <\/p>\n
Massive tyrannosaurs probably emerged as an evolutionary adaptation to the availability of large herbivores, the authors wrote. However, exactly why giant plant-eating dinosaurs evolved is still an unexplained mystery, according to the study. <\/p>\n
Fiorillo emphasized that it\u2019s a \u201chighly speculative\u201d idea for now, but he added that, unlike the pygmy tyrannosaur found in the Arctic \u2014 called Nanuqsaurus hoglundi \u2014 T. mcraeensis probably didn\u2019t experience dramatic shifts in temperature and light in southern North America so it was able to continue to grow. Arctic conditions may have played a role in N. hoglundi\u2019s distinctly diminutive size, but in general other tyrannosaurids from the same time period were much smaller than T. mcraeensis. <\/p>\n
The research team will now return to the rock formation where the specimen was unearthed to see whether they can find more bones. <\/p>\n
\u201cThen, because it\u2019s so big, we need to actually shift some of our investigation to try to understand the paleoecology and environment in which this animal lived so we can begin to understand what was it about New Mexico that was so special that this animal\u2019s adaptation to life was to get big,\u201d Fiorillo said. <\/p>\n
When the lower jaw was first found, there weren\u2019t many T. rex specimens out there, Fiorillo said. <\/p>\n
The identity of T. mcraeensis was revealed all these decades later thanks to Sebastian G. Dalman, the study\u2019s first author who is an associate researcher at the museum as well as a paleontological consultant with the Springfield Science Museum in Massachusetts.\u00a0<\/strong> <\/p>\n While studying the bones starting in 2013, Dalman was the first person to suggest that they \u201cmight be something different,\u201d Fiorillo said. <\/p>\n As the largest apex predator of its time, T. rex has had near constant attention from the paleontological community, both professional and amateur, for decades. Fascination with the ferocious giant and outsize roles in popular films such as \u201cKing Kong\u201d and \u201cJurassic Park\u201d have upped the enthusiasm of scientists and amateur fossil hunters alike in their search for more T. rex bones, according to Fiorillo. <\/p>\n \u201cAnd that improved our sample size,\u201d he said. \u201cThat set the table for when Sebastian started to look at our specimen and say, \u2018Hey, these don\u2019t actually look the same as the famous Tyrannosaurus rex specimens from places like Montana.\u2019\u201d <\/p>\n\n A formerly unknown relative of the most iconic of all dinosaurs, Tyrannosaurus rex, has been newly identified, according to a study released Thursday. The revelation adds a new clue that could help paleontologists unravel another step in the evolutionary chain that ended with the massive predatory tyrannosaur, T. rex. Called Tyrannosaurus mcraeensis, the creature likely <\/p>\n","protected":false},"author":0,"featured_media":13961,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[23],"tags":[],"class_list":{"0":"post-13960","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-world"},"_links":{"self":[{"href":"https:\/\/shareperformanceinsight.com\/index.php\/wp-json\/wp\/v2\/posts\/13960","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/shareperformanceinsight.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/shareperformanceinsight.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"replies":[{"embeddable":true,"href":"https:\/\/shareperformanceinsight.com\/index.php\/wp-json\/wp\/v2\/comments?post=13960"}],"version-history":[{"count":0,"href":"https:\/\/shareperformanceinsight.com\/index.php\/wp-json\/wp\/v2\/posts\/13960\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/shareperformanceinsight.com\/index.php\/wp-json\/wp\/v2\/media\/13961"}],"wp:attachment":[{"href":"https:\/\/shareperformanceinsight.com\/index.php\/wp-json\/wp\/v2\/media?parent=13960"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/shareperformanceinsight.com\/index.php\/wp-json\/wp\/v2\/categories?post=13960"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/shareperformanceinsight.com\/index.php\/wp-json\/wp\/v2\/tags?post=13960"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}