Early fossil fish from China shows where our jaws came from
Where did our jaws come from? The question is more complicated than it seems, because not all jaws are the same. In a new article, published in Science, palaeontologists from China and Sweden trace our jaws back to the extinct placoderms, armoured prehistoric fish that lived over 400 million years ago.
|Life reconstruction of Qilinyu along with Guiyu and Entelognathus in Silurian waters |
[Credit: Dinghua Yang]
|Life reconstruction of Qilinyu, a 423-million-year-old fish from the Kuanti Formation (late Ludlow, |
Silurian) of Qujing, Yunnan, in Silurian waters [Credit: Dinghua Yang]
|The superbly preserved Entelognathus specimen shows its jaw is much like that of a modern bony fish |
[Credit: Zhu Min et al.]
|Diagram showing the dermal jaw bones from fish to human |
[Credit: Brian Choo and Min Zhu]
|Diagram showing the evolution of dermal jaw bones |
[Credit: Brian Choo, Flinders University]
The simplest interpretation of the observed pattern is that our own jaw bones are the old gnathal plates of placoderms, lightly remodelled. It seems like substantial parts of our anatomy can be traced back, not only to the earliest bony fishes, but beyond them to the strange ungainly armoured placoderms of the Silurian period.
Source: Uppsala University [October 20, 2016]