Ancient Fish Fossil With Human Like Face Discovered in China

Scientists have discovered a fish fossil that is believed to be the earliest known species with a modern jaw.

Fossil of a prehistoric fish Entelognathus primordialis, which existed some 419-million years ago, was found in an ancient seabed Kuanti Formation located in the Quijing prefecture in Southwest China. The discovery of this fossil fish provides an insight into how vertebrate faces evolved over a period of time.

Analysis of the 8-inch long well preserved fossil revealed that it belonged to placoderms.  Placoderms possessed a bony skull and jaw like most of the vertebrates including mammals. They had a beak like jaw that was made of bone plates and in the history of evolution Placoderms were the first jawed fish that survived in the late Silurian seas of China about 430-360 million years ago, reports the study published in the journal Nature.

It is said that all vertebrates belong to gnathostomes- a group of jawed vertebrates.  In the past, this family divided into two groups- the cartilaginous fish like the sharks and the bony fish and other four-limbed animals including humans. Till date it was believed that the common ancestor of these gnathostomes were similar to the cartilaginous fish, reports NBC News.

Scientists assumed earlier that placoderms were lost to evolutionary history and also believed that the last common ancestors of the existing jawed vertebrates lacked jawbones and were similar to sharks with skeletons made of cartilage.

 "The theory went that the bony fishes evolved later, independently developing large facial bones and inventing the 'modern' jaw. Such fishes went on to dominate the seas and ultimately gave rise to land vertebrates," said Eliot Barford of the Nature News.

Study lead  Min Zhu, a paleontologist at the Institute of Vertebrate Paleontology and Paleoanthropology in Beijing, told LiveScience that the fish had smaller bones arranged in a complex manner that is the permaxilla and maxilla on its upper jaw, lower jaw and cheekbones.

This finding has led scientists to believe that Entelognathus  might be the missing piece between the placoderms and the last common ancestor of the modern bony fish.

The authors concluded saying, "There is a serious possibility that the modern bony visage originated with E. primordial's ancestors. This would mean that humans look more like the last common ancestor of living jawed vertebrates than we thought, and that sharks are less primitive than paleontologists assumed."