Siats Meekerorum: Scarier than a T-Rex, This Cretaceous Predator Visits Raleigh
Somewhere in a forested patch of what would become Utah, two small Tyrannosaurs stalk an Iguanadontian. They chase it over flooded brooks and lush hills until they finally corner it near two fallen tree trunks.
The Tyrannosaurs snarl like lions ready to pounce, but something stops them as the pangs of hunger nip at their bellies. They look up to see four metric tons of top predator staring them down and casting a heavy shadow on the unfortunate prey.
With one lunging bite, the 40-ft long Archarodontosaur steals the Tyrannosaur’s prey and sends them scurrying to find another meal. It will take another 30 million years for Tyrannosaurs to reach their Tyrant King potential, but until then, Siats Meekerorum (See-atch Me-ker-or-uhm) enjoys its domination of the Cretaceous.
First discovered in 2008 by Lindsay Zanno of the North Carolina Museum of Natural Sciences and Peter J. Makovicky of the Field Museum of Natural History in Chicago, Siats Meekerorum fills a gap in the fossil record between early Archarodontosaurs and Tyrannosaurus Rex.
Its size, Dr. Zanno says, suggests that it was the top predator of its time and likely reigned for 30 million years or more. It probably interacted with members of the Tyrannosaur family throughout the prehistoric Americas.
“Contemporary Tyrannosaurs would have been no more than a nuisance to Siats, like jackals at a lion kill. It wasn’t until Carcharodontosaurs bowed out that the stage could be set for the evolution of T. Rex.” Dr. Lindsay Zanno
As Director of the Paleontology and Geology Research Laboratory in downtown Raleigh, Dr. Zanno oversees fossil preparation and volunteer programs as she works to describe new specimens like those that belonged to Siats.
The Siats specimens belonged to a juvenile. We can be reasonably sure about that because bones grew in prehistoric times the same way they do today. The bones uncovered by Dr. Zanno include neural arches that, in adulthood, would be completely fused with the centra in the vertebral column. This is like when a child’s baby teeth fall out; it’s a feature of growing up we can point to for a good estimate of age.
Plugging a gap in our knowledge isn’t the only exciting part of this discovery. Finding such a large creature in Utah means there are still important discoveries to be made in the Americas.
“It’s been 63 years since a predator of this size has been named from North America,” Dr. Zanno reminds us.
The last predator of this size named from America was Siats’ cousin, Acrocanthosaurus, in 1950. Acrocanthosaurus fossils have been found in Wyoming, Texas, and even Maryland, suggesting their territory was spread far and wide.
Acrocanthosaurus proudly stands in the North Carolina Museum of Natural Sciences, one block away from the Paleontology and Geology Laboratory where Dr. Zanno and company studied Siats Meekerorum before declaring it a new species on November 22nd. Outside the lab many local fossils are on display from all over North Carolina, including Durham and Chatham counties.
Although some of the best preserved specimens have been found in the Rocky Mountain range, dinosaur fossils can be found nearly everywhere.
Paleontology is an exciting field filled with great minds and elbow grease, and there’s always more work to be done. For more information about Siats Meekerorum, visit the Museum’s web site, or check out these videos.
Siats isn’t on display, but a towering replica of Acrocanthosaurus overlooks West Jones Street from its perch in the atrium. Standing below its quiet roar should be on every must-see list, and is certainly one of Raleigh’s greatest highlights. Perhaps one day we”ll know more about Siats and the time in which it lived- its environment, contemporaries, and so forth- and that knowledge will help us understand more about the times in which we live.
Siats teaches us that as long as there’s more to find, there’s more to learn.