Pseudoangustidontus

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 in 2006, but due to the fragmentary remains known at the time, its classification was debated, but with more complete fossils, this taxon was identified as a hurdiid radiodont in 2023. Similarly to its larger relative, Aegirocassis benmoulae, this radiodont is thought to have lived a primarily filter feeding lifestyle, using its numerous auxiliary spines to grab small organisms from the water.