Researchers from North Carolina and Chicago announced the discovery a new dinosaur today.
Siats Meekerorum (known colloquially as "SEE-ahtch") is thought to have been one of the three largest predators in America, at one time even larger than the Tyrannosaurus. This particular specimen was 30 feet long... and it's an adolesent.
Dr. Lindsay Zanno, a paleontologist at N.C. State and the North Carolina Museum of Natural Sciences, is one of the co-discoverers. She told WUNC that we're still trying to figure out what led to Siats's demise. But there are theories.
"We know there was climate change," said Zannos. "We had a warming planet. There was sea level rise at the time. So a lot of the things we're facing now in our modern eco-systems were also stressing out the animals at the time that Siats lived."
Zanno says there's been a big hole in what we know about dinosaur evolution for some time.
"We know a lot about the dinosaurs of the late Jurassic and the late cretaceous. These are all the dinosaurs we grew up with as kids; triceratops, stegosaurus, and T-rex. But in-between those really famous dinosaur faunas is a huge gap in our understanding of dinosaur evolution on the planet."
It took the extinction of Siats for the Tyrannosaurus to become the apex predator. Zannos hopes to learn what it was that caused Siats to disappear, but allowed other predators to thrive. She says it might provide clues as to current predators facing extinction.
The new species is named for a mythical creature of the Ute tribal people, from the region in Utah where the fossils were discovered. The fossils are being kept at the field museum for more study, and probably won't be available for public viewing for quite some time.
