Fezouata Formation fossils

Aegirocassis (″Aegir's helmet″) is an extinct genus of giant radiodont arthropod belonging to the family Hurdiidae that lived 480 million years ago during the early Ordovician in the Fezouata Formation of Morocco. It is known by a single species, Aegirocassis benmoulai. Van Roy initiated scientific study of the fossil, the earliest known of a "giant" filter-feeder discovered to date. Aegirocassis is considered to have evolved from early predatory radiodonts. This animal is characterized by its long, forward facing head sclerite, and the endites on its frontal appendages that bore copious amoun

genus of arthropods (fossil)

Selenopeltis () is an extinct genus of odontopleurid trilobites in the family Odontopleuridae.

Geragnostus is a genus of very small agnostid trilobites whose fossils are found Ordovician-aged marine strata from Eurasia, North America and Argentina.

Pseudoangustidontus (meaning "false Angustidontus") is a genus of hurdiid (peytoiid) radiodont from the Lower Ordovician of Morocco. This genus includes two described species, '''Pseudoangustidontus duplospineus and Pseudoangustidontus izidigua', which both belong to the smaller Aegirocassisinae subfamily, however, a third unnamed species is also known. This animal is only known from the Fezouata Formation, a lower Ordovician fossil site in Morocco that is of Konservat-Lagerstätten status, meaning that the fossils from this site are exceptionally well preserved. This taxon was first described