Human jaws evolved from ancient fish

Prehistoric fossils found in China include bones with jaw characteristics of modern vertebrates.

Scientists published the results of a study of Qilinyu prehistoric fossil fish , about 30cm long, appearing 423 million years ago, excavated in Yunnan Province, China in the October 21 issue of Science. The fish has a bone-like jaw section of modern vertebrates, including humans, according to Reuters.

Ancient fish fossils are characterized by modern vertebrate jaws.(Photo: Dinghua Yang).

Fish appeared more than 500 million years ago, the first vertebrate in the world. However, in primitive times, they did not have jaws. Catfish is the first vertebrate to have a jaw, an important evolutionary step that helps them catch prey. They have the head and most of the body covered with armor, the jaw line has bone blades that act as teeth to tear and crush the prey.

Qilinyu belongs to the skinfish, but has three bones, including the lower jaw, the upper jaw and the jaw. This is a feature of a modern vertebrate jaw.

"In humans, the lower jaw is completely composed of the lower jaw bone. The upper jaw is made up of the upper jaw bone but the front teeth are the vestiges of the front jaw," Per Ahlberg, a paleontologist at the Great Study Uppsala, Sweden, explain.

This finding contrasts with the previous view that modern jaws evolve later, occurring in the early stages of the bony fish layer. "We now know that a limb genus evolves into a modern vertebrate and jaw," Ahlberg said.