Order Birkeniida Berg 1937 (vertebrate)
Parent taxon: Anaspida according to J. A. Long 2011
Sister taxa: Anaspidiformes, Birkeniiformes, Conopiscius, Endeiolepidiformes
Subtaxa: Cowielepis
Ecology: planktonic suspension feeder
Distribution:
• Silurian of Estonia (2 collections), the United Kingdom (2)
Total: 4 collections each including a single occurrence