Now we'll go a little further back in time. This is a mass mortality plate of Protopteraspis sp. It's comprised of body shields from some of the first armored fish. They occurred before the evolution of moveable jaws. From the Devonian age.
I got really excited when I found this skull. I thought it was a Pteridactyl or other flying reptile. But, the nares and skull bone constructions were all wrong. Turns out it's a gar-pike or false-gar called Aspidorhynchus brevissemis(?-possible name updated recently).