The newly named tyrannosauroid dinosaur - named Suskityrannus hazelae after the local Zuni word for coyote, "suski"- was only slightly larger than the skull of T-Rex, says Sterling Nesbitt, an assistant professor with Department of Geosciences in the Virginia Tech College of Science.
Suskityrannus was around 2.7 to 3.6 meters long, it stood from 0.6 to 0.9 meter at the hips, and it weighed no more than 40 kilograms.
It is thought to have weighed up to 90lb, compared with nine tons for a fully grown T-rex. Its diet likely consisted of the same as its larger meat-eating counterpart, with Suskityrannus hazelae likely hunting small animals, although what it hunted is unknown.
"Suskityrannus hazelae gives us a glimpse into the evolution of tyrannosaurs just before they take over the planet", said Dr. That discovery led to a lengthy investigation, and Nesbitt - now a Virginia Tech paleontologist - is part of a team publishing the findings in the journal Nature Ecology and Evolution. "It also belongs to a dinosaurian fauna that just proceeds the iconic dinosaurian faunas in the latest Cretaceous that include some of the most famous dinosaurs, such as the Triceratops, predators like Tyrannosaurus rex, and duckbill dinosaurs like Edmotosaurus".
Suskityrannus "represents a side-branch of the [tyrannosauroid] family" and is "not a direct ancestor" of T. rex and other big tyrannosaurs, he said. It was only until other small tyrannosauroids were discovered that they began re-examining this important find, which Smithsonian Institution paleobiologist Hans Sues believes is "the first really good record of the early tyrannosaurs in North America".
Tyrannosaurus rex, like the kind wreaking havoc in "Jurassic Park", reigned as king of the dinosaurs between 66 million and 80 million years ago.
Prior to Nesbitt's discovery, Robert Denton, now a senior geologist with Terracon Consultants, discovered a partial skull of the new dinosaur in 1997.
Also present on the dig were James Kirkland, now of the Utah Geological Survey and dig leader, Doug Wolfe, who is also co-author on the paper, released yesterday. "Clearly the most complete individual skeleton we had found in the entire basin and we had not even started to collect it".
At first, what they thought they had were the remains of something closer to a Velociraptor, Nesbitt explained, according to the release.
"We did not know these fossils represented a tyrannosauroid for more than a decade after they were discovered", Nesbitt told Gizmodo in an email. Its final home with be at the Arizona Museum of Natural History. "I am now an assistant professor that gets to teach about Earth history". After 2006, Nesbitt brought the fossils with him through various postings as student and researcher in New York, Texas, Illinois, and now Blacksburg. "So she's been instrumental to organizing and mentoring young students like I was back then", said Nesbitt. "If we did not find the two specimens of Suskityrannus we would have never known this animal existed".