Plants and Animals

Researchers Discover Huge Mega-Predator Dinosaur

November 22, 2013 | by Lisa Winter

Photo credit: Jorge Gonzales

For the first time in 60 years, a gigantic mega-predatory dinosaur has been discovered in the United States. Beyond that, it is one of the top three largest carnivores ever found in North America. The announcement comes from Lindsay Zanno from North Carolina State University and was published this morning in Nature Communications.

Dr. Lindsay Zanno dubbed the dinosaur Siats meekerorum as tribute to a Native American legendary creature, the Siats (pronounced as See-otts). According to this legend, the Siats was a terrible man-eating creature. While Siats the dinosaur obviously did not eat man due to a nearly 100 million year gap in existence, it seemed to be a fitting title for such a large predator. Also, the dinosaur was discovered in Utah near the area where the legend originated. Zanno has expressed a dislike for dinosaur names ending in “-saurus” and wanted to give it a name with a bit of an edge. The specific name meekerorum was given in tribute to the Meeker family who supports burgeoning paleontologists at the Field Museum in Chicago.

The dinosaur lived about 100 million years ago in the transitional time between the Jurassic and Cretaceous periods. Unfortunately, not a lot is known about what happened at this time, though this discovery puts Siats as top predator for about 30 million years in what was previously a large gap in the fossil record. After Siats went extinct, tyrannosaurs were able to take top billing. There is currently no information about how it may have interacted (or not) with Lythronax argestes, a large tyrannosaur that was also recently announced out of Utah. L. argestes has been dated to 80 million years ago.

The partial skeleton that has been used to make this announcement was first discovered in 2008. Though the specimen was not fully grown, the researchers speculate that adults may have grown to be 30 feet (9.1 meters) long from tip to tail. Additionally, it is difficult to guess what Siats would have actually looked like. While bone structure and overall body shape can be derived from the skeleton, the actual coloration of the skin and feathers is largely hypothetical. Artist Jorge Gonzales has depicted Siats as having brown skin, soft feathers, and a black stripe on the face that looks incredibly cool, kind of like war paint.

Zanno has urged the public to “stay tuned” for more announcements of animals from this time frame. Hopefully these announcements will fill in many of the gaps from this time frame and further our understanding of the evolution of life on Earth.