New dinosaur species unearthed in Chile had knives on its tail


Fossils found in Chile are from the bizarre dog-sized dinosaur species called Stegouros that had a unique slashing tail weapon.

Illustration by Mauricio Alvarez via AP

In a southern and sparsely populated region of Chile, scientists excavated the skeletal remains of a naturally armored dinosaur that lived over 70 million years ago, during the late Cretaceous period. Much to the team’s surprise, they found it possessed a rather bizarre feature — knife-like artillery in place of a tail.

Although echoing beings straight out of fantasy novels, armored dinosaurs are a well-known crew. Ranging from the sharply adorned Kentosaurus to the curvy backed Hesperosaurus, paleontologists have already studied a long list of the naturally shielded animals. But this new member of the warrior-like troop of beings piqued researchers’ interest because of its specialized armament that could’ve once sliced through enemies. 

The ancient herbivore “evolved a large tail weapon unlike any dinosaur,” the team said about their discovery in a report published Wednesday in the journal Nature. The dinosaur’s oddly shaped backside is decorated with a whopping seven pairs of bony deposits fused together, emulating actual blades. 

The team dubbed the two-meter (about six and a half foot) long species Stegouros elengassen due to the rest of its body resembling the Stegosaurus — a.k.a. Spike from The Land Before Time. Later, extensive DNA analysis and cranial examination revealed the animal to be more closely related to a dinosaur family called Ankylosaurs, but the team decided to keep the initial name.

However, “Unlike the Ankylosaurs of the northern hemisphere, our new dinosaur possesses light armor, slender legs, and a smaller size,” Sergio Soto Acuña, lead author of the study and a doctoral student at the University of Chile, told CNN, comparing the tail to that of a rattlesnake. 

Presumably, the dangerous appendage was used to defend against predators — but either way, “it’s a really unusual weapon,” Alex Vargas, co-author of the study and a University of Chile paleontologist, told the Associated Press. 

“Books on prehistoric animals for kids need to update and put this weird tail in there … It just looks crazy.”