The 419-million-year-old fish fossil could help explain when and how vertebrates, including humans, acquired our faces—suggesting a far more primitive origin for this critical feature of our success, a new study says.

"Entelognathus primordialis is one of the earliest, and certainly the most primitive, fossil fish that has the same jawbones as modern bony fishes and land vertebrates including ourselves," said study co-author Min Zhu of the Chinese Academy of Sciences in Beijing.

"The human jaw is quite directly connected to the jaw of this fish, and that's what makes it so interesting."

The bones comprising the fish's cheek and jaws appear essentially the same as those found in modern bony vertebrates, including humans, Zhu added. Because it boasts maxilla and mandible much