STATES CHRONICLE – Scientists have revealed that studies demonstrate human jaws evolved from our prehistoric swimmers ancestors. That species of fish was thought to have lived four hundred years ago. The study was published in the Science magazine. It unveiled a fossil of a fish in China. The skeleton has the form of a classic placoderm, displaying three bones which are also part of human jaws. This species of prehistoric swimmers had a similar structure as ours, exhibiting similarities of the maxilla, premaxilla, and teething.
Nevertheless, the placoderms’ jaws were incredibly powerful and sharp, being known as “gnathal plates.” This was the reason why scientists have given up to the idea that our jaws are similar to our prehistoric swimmers ancestors. The peculiarity of gnathal plates is incalculable. The strength of placoderms’ jaws cannot be compared to our jaws’ strength. What is more, the bones of the jaw were displayed at some distance one from the other, suggesting that each bone evolved independently of the others, having nothing in common with the evolution of our jaw.
However, this species of prehistoric swimmers still share three common characteristics of the jaw with us. The fossils of a placoderm called Qilinyu and a Silurian Entelognathus fish which were discovered back in 2013 have brought to light evidence that we have more in common with fish than we think. Regarding the fact that both Qilinyu and Entelognathus have approximately the same structure, displaying a very bony jaw with vigorous and sharp teeth, they have different lifestyles. They used various methods of catching their prey, and they are very different in looks.
Zhu Min, a member of the Chinese Academy of Sciences, has argued that both Qilinyu and Entelognathus present a mixture between the placoderm’s gnathal plates and very bony fish jaws. Scientists have also claimed that the gnathal plates of the placoderm displayed an inner arcade of the jaw. They were placed in the same way in which bony fishes had their teeth. Thus, scientists would expect to discover gnathal plates in the maxilla, dentary, and premaxilla of Qilinyu and Entelognathus. Unfortunately, there is nothing in their structure that proves this.
After all the debates and analysis, scientists can be sure of only one thing: our jaws have evolved from placoderm’s gnathal plates.
Image source: wikipedia