ARI SHAPIRO, HOST:
Today scientists announced that they have discovered a new animal. Actually, a very old one. It is a fossilized sea creature that once lived in what's now central China. NPR's Rachel Ellen Bichell reports that the tiny organism could provide clues about how some modern animals evolved.
RAE ELLEN BICHELL, BYLINE: When scientists like Simon Conway Morris discover a new animal, they get to name it. But when he and his colleagues in China found this 540 million-year-old fossil, they decided to skip the compliments.
SIMON CONWAY MORRIS: We arrived at the word Saccorhytus, which basically means a wrinkled bag.
BICHELL: Actually, this thing is a lot uglier than a wrinkled bag. It's basically a giant gaping mouth with spikes and some extra holes, probably for oozing waste.
CONWAY MORRIS: (Laughter) Yes, doesn't sound too appetizing, does it?
BICHELL: Fortunately, it was only the size of a grain of rice.
CONWAY MORRIS: It has a very small body. It doesn't have a tail. It does not appear to have eyes.
BICHELL: It sounds primitive, but compared to the other life in that area this slithering, clambering little blob of an animal was on the cutting edge. This was a time in Earth's history when algae was just about the most exciting thing floating around. Conway Morris of Cambridge University in the U.K. described the ancient sand dwellers in the journal Nature. He and his colleagues think it's a really important find.
CONWAY MORRIS: So what we have here is an animal which we would suggest is, in fact, the earliest known deuterostome.
BICHELL: Deuterostomes are a huge group of organisms that over millions of years would come to include starfish, sea squirts and anything with a spine, including us. This critter represents a surprising and not very attractive beginning to the huge diversity of life we see today. For example, those holes for using waste - structures like those may have eventually evolved into gills.
CONWAY MORRIS: I think what is really exciting about the fossil record is that it shows us, in a sense, what the missing links actually look like.
BICHELL: Half a billion years ago, life on Earth was getting interesting. And some of that action was happening on a tiny scale, hidden between grains of sand. Rae Ellen Bichell, NPR News.