This image is of a Melonechinus multipora  (Norwood & Owen, 1846) sea urchin fossil on display at Natural History Museum Vienna ( Naturh...

This image is of an Archaeocidaris sp (McCoy, 1844) sea urchin fossil on display at Natural History Museum Vienna ( Naturhistorisches Museu...

My cousin back from a recent field expedition found a large (5 cm) tooth-plate fossil. It appears to be a holocephalan known as Psammodus (...