Mcnamaraspis

It has been quite a while since I did a Clades post, and this one will be featuring a group that has lots of figures...but mostly one species. It is (as stated in the title) the placoderm group Arthrodira. Although pretty diverse overall, the most familiar would of course be Dunkleosteus, a giant predator of Devonian seas worldwide. But of course it lived alongside several relatives in those seas--the Arthrodira (as described in my database as a grade) includes the…