This 242-million-year-old creature swam the seas before most dinosaurs roamed the planet. It’s the oldest known marine reptile to feast exclusively on plants. And its mouth is full of mysteries.
Its name, Atopodentatus unicus, which is Latin for “unique strangely toothed,” provides a clue to its puzzled past. Paleontologists in China
first found its fossils in 2014, and believed it had a jaw shaped like a flamingo’s beak with a zipper of teeth down the middle.
But those assumptions were wrong, according to a new paper published Friday in the journal Science Advances. Rather than a downward-turned snout, the reptile actually had a flat hammerhead-shaped face, the paper says.
The team figured out how its mouth actually worked after finding two new fossils of the reptile that were much better preserved than the first find.
They said the crocodile-size creature used its front teeth to scrape algae from the seafloor, which it would suck up like a vacuum. Then it would use its needle-like teeth to trap the plants and filter out water, like a whale with baleen.
Although they may have cleared the confusion, they admit the anatomy is still surprising.
“A hammerhead in a reptile is such a ludicrous thing to think of,” said Olivier Rieppel, a paleontologist at the Field Museum of Natural History in Chicago
and a co-author of the paper. “But it exists and it’s the earliest marine herbivore — it’s quite amazing.”