In a fossil first, paleontologists have discovered that a dinosaur related to the T. rex and modern birds started out life with a full set of chompers, but grew up to lose them all. In place of pearly whites, the adults sprouted a beak instead.
It’s a strange metamorphosis, like an extra twisted, dinosaur-version of that nightmare where all your teeth fall out. And it’s the first time this phenomenon has ever been seen in living, dead, or extinct reptiles — which typically replace lost teeth with new ones. In fact, only a couple of animals, like the platypus and a few species of fish, go through this kind of developmental tooth loss. And until this discovery, no dino in the fossil record lost its teeth like this to grow a beak.
It’s an extra twisted, dinosaur-version of that nightmare where all your teeth fall out
The findings, published Thursday in the journal Current Biology, could possibly help scientists understand how bird beaks evolved. But these dinos didn’t directly give rise to birds — they’re more like great aunts and uncles. So it’s also likely that they’re an evolutionary oddity with little bearing on modern bird beaks, David Evans, curator of vertebrate paleontology at the Royal Ontario Museum, told the Christian Science Monitor.
Called Limusaurus inextricabilis, which means inextricable mud lizard, these dog-sized dinosaurs once roamed northwestern China during the late Jurassic between 156 and 161 million years ago. Many died in muddy pits, which some scientists think were formed when larger dinosaurs wallowed in the mud, like pigs. The small limusaurus dinosaurs weren’t able to extricate themselves from the sticky mire and died there, emerging millions of years later as fossils.