Silurian-Devonian Jawless Fish were Ecologically Diversified

[LabRatKing]

Via Sci-News:

Osteostraci, the jawless sister group to all jawed vertebrates, had adaptations for passive control of water flow around the body, according to new research led by the University of Bristol.

 

http://www.sci-news.com/paleontology/ecologically-diversified-osteostraci-08916.html

 

Full original paper-no paywall:

Computational Fluid Dynamics Suggests Ecological Diversification among Stem-Gnathostomes

https://www.cell.com/current-biology/fulltext/S0960-9822(20)31362-2

 

Generalized translation:

Armored fish developed streamlining and  passivecontrol surfaces adapted for efficiency while swimming, as in form over function. Also the big armored heads likely did not have much impact on the later development of jaws and related structures. Or, even simpler, these guys were really efficient at moving through the water even with big, heavy heads  and the more modern mouth that evolved later did not necessarily result in greater numbers of different shapes among species.