Cephalaspidomorphi

Cephalaspidomorphs
Temporal range: 438–359 Ma[1][2] Cephalaspidomorphs may have survived to the present day if lampreys and/or gnathostomes are their descendants
Life restoration of Cephalaspis lyelli.
Scientific classification
Kingdom:
Phylum:
Subphylum:
Infraphylum:
(unranked):
Cephalaspidomorphi
Type species
Cephalaspis lyelli
Agassiz, 1835
Subgroups

Osteostraci
Galeaspida
Pituriaspida
Gnathostomata?

Cephalaspidomorphs are a group of jawless fishes named for Cephalaspis of the osteostracans. Most biologists regard this taxon as extinct, but the name is sometimes used in the classification of lampreys, because lampreys were once thought to be related to cephalaspids. If lampreys are included, they would extend the known range of the group from the Silurian and Devonian periods to the present day. They are the closest relatives of jawed fishes, who may have emerged from within them; if this is true, they would survive if the jawed fish are included.

  1. ^ Gai Z, Lu L, Zhao W, Zhu M (2018) New polybranchiaspiform fishes (Agnatha: Galeaspida) from the Middle Palaeozoic of China and their ecomorphological implications. PLoS ONE 13(9): e0202217. doi:10.1371/journal.pone.0202217
  2. ^ Sansom, Robert S.; Randle, Emma; Donoghue, Philip C. J. (February 7, 2015). "Discriminating signal from noise in the fossil record of early vertebrates reveals cryptic evolutionary history". Proceedings of the Royal Society B. 282 (1800): 20142245. doi:10.1098/rspb.2014.2245. PMC 4298210. PMID 25520359.