Gerastos is a small Proetida trilobite from the Devonian of Morocco. They come from the Atlas Mountains and are defined with a very granulose, bulbous glabella and short genal spines. Despite their small size (averaging less than an inch) they have have amazing surface detail when prepared correctly. Gerastos tend to be fairly inexpensive trilobite to acquire since they are relatively common and the small size means they don't take as much time to prepare. We always have nice specimens of Gerastos trilobites for sale as reasonable prices.