Amphiaspidoidei

Amphiaspidoidei is a taxon of extinct amphiaspidid heterostracan agnathans whose fossils are restricted to Lower Devonian marine strata of Siberia near the Taimyr Peninsula. In life, the amphiaspidids of Amphiaspidoidei are thought to be benthic animals that lived most of their lives mostly buried in the sediment of a series of hypersaline lagoons. Amphiaspids are easily distinguished from other heterostracans in that all of the plates of the cephalothorax armor are fused into a single, muff-like unit, so that the forebody of the living animal would have looked like a potpie or a hot waterbottle with a pair of small, or degenerated eyes flanked by preorbital openings, a pair of branchial openings for exhaling, and a simple, slit-like mouth.

Amphiaspidoidei Temporal range: Early Devonian
Amphiaspis argo reconstruction
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Pteraspidomorphi
Subclass:	Heterostraci
Order:	Cyathaspidiformes
(unranked):	Amphiaspidida
Superfamily:	Amphiaspidoidei
Families
Amphiaspididae Edaphaspididae Gabreyaspididae Olbiaspididae

Taxonomy

The superfamily Amphiaspidoidei contains four families.

Amphiaspididae

This family contains two monotypic genera, including the type genus Amphiaspis, and Amphoraspis

Edaphaspididae

This family is monotypic, and contains the monotypic genus Edaphaspis.

Gabreyaspididae

This family contains four genera, Gabreyaspis, Prosarctaspis, Pelaspis, and Tareyaspis.

Olbiaspididae

This family contains three genera, Olbiaspis, Kureykaspis and Angaraspis.

References