Ever since 1902, when a fossil hunter discovered some enormous fossilized legs and hips, people have argued about Tyrannosaurus rex—what the dinosaur looked like, how it stood and moved and ate, to what it end it used its wee little arms, etc. and etc. They have argued formally by writing scientific papers criticizing scientific papers that, in turn, criticized other scientific papers, or informally by smashing their fingers into keyboards to say that a Tyrannosaurus with feathers looks “weird and gay.” If any of the billions of T. rex that roamed the Earth in any given year more than 67 million years ago were alive to see this discourse, they probably have weighed in by eating the arguers with their banana-sized teeth.
T. rex—whose name essentially translates to Tyrant Lizard King—never asked to be royalty. But at the time of its discovery, T. rex had the misfortunate of being 1) big 2) scary-looking and 3) an unwitting symbol of one powerful man’s racist, anti-Semitic, and eugenicist beliefs, qualities that helped destine it to become the most famous and most debated dinosaur of all time. Debates in science are normal and good, because they help improve the scientific process. But these debates can be confusing to anyone who doesn’t already have a grounding in the subject and can leave the public attached to a certain interpretation of fossils that are incorrect. (For example, the dinosaurs called Velociraptor in the movie Jurassic Park actually represent Deinonychus, a Mongolian cousin that was twice as tall, a taxonomic mistake that may have been inspired by paleoartist Gregory Paul’s 1988 book that Michael Crichton cited as inspiration for his novel.)
In February of this year, three researchers, including Paul, published a bombshell paper in the journal Evolutionary Biology arguing that T. rex should actually be split into three species. In July, in the same journal, seven other researchers published a vehement refutation of the February paper—the first peer-reviewed dismantling of the February paper. Both papers made national headlines. “This is not the first debate among paleontologists as to whether a particular bunch of similar fossils actually represent one species or multiple species,” said Darla Zelenitsky, a paleontologist at the University of Calgary who was not involved in either paper. “The species Tyrannosaurus rex is iconic so we are hearing more about it in this case.”
Most paleontologists have sided with the rebuttal, believing that current evidence points to a single species of T. rex. Still, the first research group refuses to back down from its claims, even calling the refutation “paleopropaganda.” This saga raised a lot of questions for me, and probably many other people. Is the debate settled? How can you tell if a fossil is one species or another? Should you even care? So I asked some wise people to share their thoughts on the T. rex species saga and what to take away from it all, and will now explain it to you as simply as I can.
Tyrannosaurus context
Tyrannosaurus rex is a species of theropod dinosaur, a group of dinosaurs that walked on two legs and had three walking claws on each foot, and which also technically includes all birds. T. rex as big as school buses roamed around North America from around 68 to 66 million years ago in the late Cretaceous period. Since the first T. rex was unearthed in Montana, scientists have found many more. T. rex “is represented by dozens of individuals and hundreds of bones,” said Elena Cuesta, former researcher at the Paleontological Museum of Munich. Some specimens bear awe-inspiring nicknames like “Black Beauty” and “Titus,” and some are called “Stan” and “Sue.”
Each new specimen teaches us more about the species, and ongoing research has proven many of our initial assumptions were wrong. For example, the first T. rex unveiled to the public was posed standing upright with a dragging tail like Barney the…
Read More: The T. Rex Species Saga, Explained