Recently Discovered Fossil Gives New Clues about Origin of Prehistoric Marine Reptile

Millions of years ago, an ancient, marine reptile stalked the Earth. With its trademark crushing teeth, it swam through prehistoric seas, feeding on shellfish and crustaceans. Before now, though, scientists didn't know where this marine reptile, called a placodont, actually came from. Now they've found new fossil evidence that shows when and where the species existed.

For 50 million years, the placodont populated the flat coastal areas of the Tethys Ocean. The crushing teeth that it possessed were its most distinctive feature. The upper jaw had two rows of flattened teeth--one on the palate and one of the jawbone. The lower jaw, in contrast, had only one set of teeth.

The new, 246-million-year-old fossil was found by a Swiss and German team in the Netherlands. The ancient skull of the juvenile placodont was extremely well-preserved considering that it was less than an inch in size. In addition, a few specific characteristics set it apart from previously discovered fossils.

Most placodont fossils feature a double row of crushing teeth in the upper jaw. These flattened teeth allowed the creatures to smash the tough outer shells of crustaceans. This latest fossil, though, didn't have the same teeth.

"Unlike the other placodonts discovered to date, the Winterswijk specimen has conical, pointed teeth," said Torsten Scheyer, one of the researchers, in a press release, "which means the pointed teeth on the lower law slotted precisely into the gap between the palate and upper-jawbone teeth when biting."

Although it does sport the pointed teeth, it also has the trademark double row of teeth on the upper jaw, which proves that it is indeed a placodont. Researchers believe that this particular species, which they've dubbed Palatodonta bleekeri, specialized in gripped soft prey with their pointed teeth. In addition, researchers believe that it's possible that this specimen is a very early form of the placodont and that it wasn't until later that the marine reptile evolved crushing teeth in order to cope with shells.

Yet the researchers didn't only find out about the early history of the placodont with this new fossil. The remains also shed light on where the marine reptile originated. Although previous finds suggested that it lived in sea shelf areas near present-day China or Europe, this new fossil seems to point toward a definite European origin. The findings could allow researchers to better understand how these creatures evolved and adapted to their changing environment.

The findings are published in the journal Nature Communications.