Fossils found in Chile are from a strange-looking dog-sized dinosaur species that had a unique slashing tail weapon, scientists reported this week.
Some dinosaurs had spiked tails they could use as stabbing weapons and others had tails with clubs. The new species, described in a study in the journal Nature, has something never seen before on any animal: seven pairs of "blades" laid out sideways like a slicing weapon used by ancient Aztec warriors, said lead author Alex Vargas.
"It's a really unusual weapon," said Vargas, a University of Chile palaeontologist. "Books on prehistoric animals for kids need to update and put this weird tail in there ... It just looks crazy."
The plant-eating critter had a combination of traits from different species that initially sent palaeontologists down the wrong path. The back end, including its tail weapon, seemed similar to a stegosaurus, so the researchers named it stegouros elengassen.
![This illustration provided by Mauricio Alvarez shows a Stegouros, a bizarre dog-sized dinosaur species that had a unique slashing tail weapon. Photo / AP](https://www.nzherald.co.nz/resizer/v2/5BRGVVBEOFHVERBN5PSOYB7YGU.jpg?auth=560f848ddbc0d0537774e1cb8b45b104b8eb64df62749cecaa37eacedc9c45af&width=16&height=21&quality=70&smart=true)