(CNN) Everyone knows that ancient monsters walk among us -- alligators, crocodiles and birds all have characteristics that date back millions and millions of years. But a newly indentified dino cousin may shake up the prehistoric family tree.
The findings were published this week in Nature, an international scientific journal, and they concern the Teleocrater, the earliest-known dinosaur relative.
The Teleocrater was a six-foot-long lizard-like creature that kind of looked like a crocodile. That seems pretty run-of-the-mill, but the Teleocrater is special because it was around before dinosaurs even properly existed, which means it may change the way paleontologists think about how dinosaurs evolved.
Follow us here: Dinosaurs actually belonged to a larger group called archosaurs, which also includes birds, flying reptiles and crocodilians. Paleontologists believe that archosaurs split into two groups and then rapidly evolved: One group became dinos and bird and flying reptiles, and the other became crocodilians. But the Teleocrater existed after this split, on the bird-like side of the family. So why did it have crocodilian characteristics?
"Teleocrater has unexpectedly crocodile-like features that are causing us to completely reassess what we thought about the earliest stages of dinosaur evolution," says the paper's co-author Ken Angielczyk, who is also the associate curator of fossil mammals at The Field Museum. "Surprisingly, early dinosaur relatives were pretty profoundly not dinosaur-like."
To the untrained eye, of course, it looks extremely dinosaur-like. But the paper's authors point out the differences: It's long and short like a crocodile; about six to ten feet long and only two feet tall. Its joints could rotate from side to side, meaning it probably walked more like a crocodile too -- think side to side as opposed to the up-and-down motion of say, and ostrich walking. The fact it walked on four legs sets it apart from most animals on that side of the split during this point in archosaur evolution.
That means the Teleocrater fills in an important gap in the fossil history.
"Scientists generally don't love the term 'missing link,' but that's kind of what Teleocrater is," Angielczyk explains. "A missing link between dinosaurs and the common ancestor they share with crocodiles."