Protopteraspididae

Protopteraspididae
Temporal range: Early Devonian
Protopteraspis gosseleti
Scientific classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Subphylum: Vertebrata
Infraphylum: Agnatha
Class: Pteraspidomorpha
Subclass: Heterostraci
Order: Pteraspidiformes
Family: Protopteraspididae
Genera

Protopteraspididae is an extinct family of pteraspidid heterostracan agnathans. Fossils of the various genera are found in early Devonian-aged marine strata. Protopteraspidids were once thought to represent a taxon of basal pteraspidids (hence "proto") but recent evaluations demonstrate that Protopteraspididae is a paraphyletic group of various transitional forms representing a gradual transition between the more advanced Pteraspoidei (comprising Pteraspididae, Gigantaspis and Protaspididae), and the anchipteraspidids and the Psammosteids.