Psammosteida also called as Psammosteoidei is a suborder of pteraspidid heterostracan agnathans.
The psammosteids had broad, flattened bodies, suggesting a predominantly benthic habit.
Other notable psammosteids include Psammosteus, and Obruchevia, two genera of enormous species with dorsal shields around one meter in diameter.
The Psammosteids were the only heterostracans to survive to the end of the Devonian, where they finally perish during the Hangenberg event.
You can help Wikipedia by expanding it.This article related to a Devonian jawless fish is a stub.