Amphiaspididae

Amphiaspidae
Temporal range: Early Devonian
Amphiaspis argo reconstruction
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Infraphylum: Agnatha
Class: Pteraspidomorpha
Subclass: Heterostraci
Order: Cyathaspidiformes
Superfamily: Amphiaspidoidei
Family: Amphiaspididae
Obruchev, 1936
Genera

Amphiaspididae is a family of extinct amphiaspidid heterostracan agnathans whose fossils are restricted to Lower Devonian marine strata of Siberia[1] near the Taimyr Peninsula. 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

  1. ^ Randle, Emma; Sansom, Robert S (27 November 2017). "Phylogenetic relationships of the 'higher heterostracans' (Heterostraci: Pteraspidiformes and Cyathaspididae), extinct jawless vertebrates". Zoological Journal of the Linnean Society. 181 (4): 910–926. doi:10.1093/zoolinnean/zlx025. Retrieved 4 March 2026.