Pterichthyodes milleri, Placoderm Pachycephalosaurus had an oval outline

had an oval outline

4 inches high

and subsequently covered it up

human hunting was likely a strong contributing factor

Their vertebral columns consisted of ten neck vertebrae

Pterichthyodes milleri, Placoderm Pachycephalosaurus had an oval outlinePterichthyodes is a genus of antiarch placoderm fishes from the Devonian period. Its fossils have been discovered in Sandwich Fish Beds of Ouoyloo, Orkney Islands, Scotland. They were one of the first species recognized for what they were, as their fossils are common in the Old Red Sandstone formation studied by geologists in the early 19th century. Due to their extreme divergence from modern day fish, they were a puzzle unsolved until Charles Darwin