Dinosaur Discovered in Utah Lived 100 Million Years Ago

By: By Laura Dattaro

Published: November 22,2013

 

 

 

 

 

An artist's concept of Siats meekerorum eating its prey. The small dinosaurs are early tyrannosaurs, which didn't evolve into their large size until Siats went extinct. (Julio Lacerda)

A new predatory dinosaur that was more than 30 feet long and weighed more than four tons has been unearthed in Utah, helping to fill in a 30-million-year gap in the North American fossil record.
A team of scientists from Chicago’s Field Museum, the North Carolina Museum of Natural Sciences and North Carolina State University found the dinosaur’s remnants in 2008 in 100-million-year-old rocks in Utah’s Cedar Mountain Formation. It is the first dino of its kind to be discovered in North America.
The beast, named Siats meekerorum after a monster from Native American mythology and in acknowledgement of Field Museum donors the Meeker family, lived 37 million years before Tyrannosaurus rex and was at the top of the food chain during its reign.
“As the apex predator of its time, it prevented contemporaneous tyrannosaurs, the forefathers of T. rex, from evolving [to a] large size,” Peter Majovicky, curator of dinosaurs at the Field Museum, told weather.com. “Only after the extinction of Siats and its kin, the allosauroids, were tyrannosaurs [able to] evolve into colossal top predators.”
Siats is the second large predatory dinosaur to be found in Utah recently. Lythronax argestes, nicknamed the “king of gore,” lived 80 million years ago and was discovered in the Grand Staircase-Escalante National Monument in 2009, with the findings announced in early November. Lyrthonax was a tyrannosaur slightly smaller than T. Rex.
(MORE: New Dinosaur That Predates T. Rex Found in Utah)
“Though of similar size and general build — big carnivores walking on hind legs with lots of blade-like teeth — Siats would likely have had a more massive forelimb with three fingers and a more lightly built skull than Lythronax, which would have had a shorter, two-fingered forelimb,” Majovicky said.
The findings were published in the November 2013 issue of the journal Nature Communications.
MORE FROM WEATHER.COM: Dinosaur Found in Utah

3 / 6

This photo released by the Natural History Museum of Utah shows the fossilized skeleton of a newly-discovered dinosaur, Lythronax argestes, which was found in southern Utah, on the display at the museum in Salt Lake City. (AP Photo/Natural History Museum of Utah, Mark Loewen)