Human Jaws Evolved From This Ancient Armored Fish

Posted: Oct 21 2016, 8:29am CDT | by , in News | Latest Science News

 
Human Jaws Evolved From This Ancient Armored Fish
Life reconstruction of Qilinyu along with Guiyu and Entelognathus in Silurian waters. Credit: Dinghua Yang
  • Humans Jaws Came From This Prehistoric Armored Fish that lived over 400 million years ago

A fossil of a fish from China clearly seems to delineate the origins of jaws.

Where did our jaws have their originating point? The question seems to haunt evolutionary scientists. The answer to it is a complicated one though.

That is because not all jaws are created equal and they seem to have a great deal of differences between them. Research in China proves that our jaws have their starting point in placoderms which are armored prehistoric fish that were extant 400 million years ago.

Jaws have a solid structure that shows personality and design in equal measures. They are a chief trait of human anatomy. It is a sign of the special place they hold for us that Steven Spielberg named his feral shark movie “Jaws”.

In embryos, jaws appear as a cartilage bar that is like a gill arch. While in a shark, these develop into full-fledged jaws, in other bony fish and human beings, novel bones appear on the sides of the cartilage.

In our own skulls, the dentary, maxilla and premaxilla go on to make the whole jaw. This of course contains the teeth.

These bones are part of bony fish and tetrapods. They are the same in a cod or a crocodile. Go back into prehistory and a species known as placoderms bear the signs of these jaw bones.

The gnathal plates look like blades and sheet-metal cutters. The relation between placoderms and bony fish is a weak one though. The new fossil which has been found has been called Qilinyu.

It comes from the same site where Entelognathus was found. It contains dentary, maxilla and premaxilla bones. Yet the two fish had different ways of living and even look different from each other.

The complexity of the structure of the jaw bones in both the Qilinyu and the Entelognathus shows that they share traits of bony fish. What we could deduce from all this is that our own jaw bones are actually the old gnathal plates of placoderms which have been modified with the passage of time.

A bit of change did take place along the way in the story of the evolution of the jaw bone. Many other parts of our modern anatomy can be traced back to placoderms. This comes as somewhat of a surprise yet it is true since it has the entire fossil record behind it.

The findings of this study got published in the journal Science.

This story may contain affiliate links.

Find rare products online! Get the free Tracker App now.


Download the free Tracker app now to get in-stock alerts on Pomsies, Oculus Go, SNES Classic and more.

Latest News

Comments

The Author

<a href="/latest_stories/all/all/20" rel="author">Sumayah Aamir</a>
Sumayah Aamir (Google+) has deep experience in analyzing the latest trends.

 

 

Advertisement

comments powered by Disqus