A new ancient sea turtle fossil has been found in China, and it's HUGE news for several reasons.
First off, because it's, well, huge.
But the other reason marine scientists are so excited about this discovery is because it fills a major hole on the turtle evolution timeline.
Before this new discovery, the oldest sea turtle was found in 2008 and called the Odontochelys semitestacea, per the Daily Mail.
That name means "toothed turtle in a half-shell."
According to Nature, where a paper on this new fossil species was published, the half-shelled turtle was different from today's modern sea turtles in two big ways: It only had a shell on its belly, and it didn't have a beak.
What's interesting about the Eorhynchochelys sinensis is that it doesn't have a shell.
But it does have a beak.
In fact, its name, Eorhynchochelys sinensis, means "first turtle with a beak," per the Daily Mail.
It was discovered 25 feet deeper than where the half-shelled turtle was, indicating that it's older. Likely 228 million years old compared to 220 million.
The fact that one ancient sea turtle species had a beak and the other had a shell, and neither had both is scientifically significant.
As Dr. Nick Fraser explained, according to the National Museums Scotland, this proves that evolution didn't happen step by step for species. So rather than all turtles getting beaks and then all those beaked turtles getting shells, two turtle species independently gained one of those characteristics.
The Daily Mail noted that turtle shells help ground them when they're digging in sand with their big flippers. The shell-less turtle likely used its beak to root around in mud and shallow water for food, and left digging to the shelled-species.
Then somewhere along the line, sea turtles gained both shells and beaks, and, likely because they were better suited for natural selection, those genetic traits stuck.