Cephalaspidomorphi

Cephalaspidomorphs
Temporal range: Cephalaspidomorphs may have survived to the present day if lampreys and/or gnathostomes are their descendants
Life restoration of Cephalaspis lyelli.
Scientific classification Edit this classification
Kingdom: Animalia
Phylum: Chordata
Subphylum: Vertebrata
Infraphylum: Agnatha
Class: Cephalaspidomorphi
Type species
Cephalaspis lyelli
Agassiz, 1835
Subgroups[3]

Cephalaspidiformes
Galeaspidiformes
Pituriaspidiformes
Gnathostomata?

Cephalaspidomorphi (alternatively called Monirhina, or simply cephalaspids)[4] is a class of jawless fishes that is presently regarded as uniting the osteostracans, galeaspids and pituriaspids. Most biologists regard this taxon as extinct, but the name is still sometimes used in the classification of lampreys because they were once thought to be descended. If lampreys are included they would extend the known range of the group from the Silurian and Devonian periods, when they are traditionally assumed to have lived, to the present day. Modern works typically assume the cephalaspidimorphs to be 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. The cephalaspidomorphs possessed armored head-shields, a heterocercal tail fin, and in some groups paired pectoral fins.

  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.
  3. ^ Nelson, Joseph Schieser (2016). Fishes of the world (Fifth ed.). Hoboken, New Jersey: John Wiley & Sons. ISBN 978-1-119-17484-4.
  4. ^ Nelson, Joseph S.; Grande, Terry C.; Wilson, Mark V. H. (2016-02-22). Fishes of the World (1 ed.). Wiley. doi:10.1002/9781119174844. ISBN 978-1-118-34233-6.

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