Amphiaspididae is a

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

of extinct amphiaspidid heterostracan

agnatha Agnatha (; ) or jawless fish is a paraphyletic infraphylum of animals in the subphylum Vertebrata of the phylum Chordata, characterized by the lack of jaws. The group consists of both extant taxon, living (Cyclostomi, cyclostomes such as hagfish ...

ns whose fossils are restricted to Lower Devonian marine strata of

Siberia Siberia ( ; , ) is an extensive geographical region comprising all of North Asia, from the Ural Mountains in the west to the Pacific Ocean in the east. It has formed a part of the sovereign territory of Russia and its predecessor states ...

near the

Taimyr Peninsula The Taymyr Peninsula ( ) is a peninsula in the Far North of Russia, in the Siberian Federal District, that forms the northernmost part of the mainland of Eurasia. Administratively it is part of the Krasnoyarsk Krai Federal subject of Russia. Ge ...

. In life, the amphiaspidids of Amphiaspididae 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 with a pair of small, or degenerated eyes, with each flanked by a preorbital opening, and a simple, slit-like mouth.

Taxonomy

''Amphiaspis''

''Amphiaspis argo'' is the type species of Amphiaspidida, and is known from an incomplete set of pillow-shaped cephalothoracic armor. The armor also appears to have a pattern of lateral sensory line canals.

''Amphoraspis''

''Amphoraspis stellata'' has a broad, rounded armor that looks vaguely like a pot or vase.

References

Amphiaspidida Devonian jawless fish Early Devonian fish Prehistoric jawless fish families Devonian fish of Asia Fauna of Siberia Fossils of Russia Early Devonian first appearances Devonian extinctions {{Devonian-jawless-fish-stub