Your Jaw May Come From This Ancient Fish

Introducing Metaspriggina, a minnow-sized fish that lived about 500 million years ago and appears to occupy a crucial branch of your family tree. Scientists say the creature might just be the ancestor of nearly all vertebrates, reports LiveScience. The revelation comes after study of dozens of remarkably well-preserved Metaspriggina fossils found in the Canadian Rockies. Researchers discovered that the fish had a pair of gill arches near the front of its body that are the "primitive precursors of the jaw," reports the Toronto Star. It's the first time such a feature has been seen in the fossil record, reports PhysOrg.

“It was a major event in the evolution of vertebrates," says the co-author of a new report in Nature. "After the creation of jaws, vertebrates were able to capture prey and (chew) food." Metaspriggina also had something called a notochord, essentially cartilage that ran the length of its body. The New York Times notes that "human embryos develop a notochord, too, but it later turns into the disks of cartilage between the vertebrae in our spine." A British Columbia expert not involved with the work says the fish is "clearly a benchmark early vertebrate, which we haven't seen before." (More discoveries stories.)