Compagopiscis

{{Automatic_taxobox

| fossil_range = Late Devonian: Frasnian, {{Fossil range|382.7|372.2}}

| image = Compagopiscis croucheri.png

| display_parents = 4

| taxon = Compagopiscis

| authority = Gardiner & Miles, 1994

| subdivision_ranks = Species

| subdivision = * Compagopiscis croucheri Gardiner & Miles, 1994 (type)

}}

Compagopiscis is an extinct genus of placoderm known from the Gogo Formation. It lived in the Upper Devonian (Frasnian stage) of Western Australia.{{Cite journal |last1=Donoghue |first1=Philip C. J. |last2=Rücklin |first2=Martin |date=2014-09-15 |title=The ins and outs of the evolutionary origin of teeth |journal=Evolution & Development |volume=18 |issue=1 |pages=19–30 |doi=10.1111/ede.12099 |pmid=25219878 |issn=1520-541X|doi-access=free }} The genus is monotypic, with its only species being Compagopiscis croucheri.{{Cite journal |last=Trinajstic |first=Kate |date=1995-01-01 |title=The role of heterochrony in theevolution of eubrachythoracid arthrodires with special reference to Compagopiscis croucheri and Incisoscutum ritchei from the Late Devonian Gogo Formation, Western Australia |url=https://www.sciencedirect.com/science/article/pii/S0016699595800999 |journal=Geobios |series=Premiers Vertandébrandés et Vertandébrandés Infandérieurs |language=en |volume=28 |pages=125–128 |doi=10.1016/S0016-6995(95)80099-9 |issn=0016-6995}}

Description

Compagopiscis is one of the earliest known vertebrates to have teeth.{{Cite journal |last1=Rücklin |first1=Martin |last2=Donoghue |first2=Philip C. J. |last3=Johanson |first3=Zerina |last4=Trinajstic |first4=Kate |author-link4=Kate Trinajstic |last5=Marone |first5=Federica |last6=Stampanoni |first6=Marco |date=2012 |title=Development of teeth and jaws in the earliest jawed vertebrates |url=https://www.nature.com/articles/nature11555 |journal=Nature |language=en |volume=491 |issue=7426 |pages=748–751 |doi=10.1038/nature11555 |pmid=23075852 |s2cid=4302415 |issn=1476-4687}} An analysis of its bite force suggests that it was a generalist predator, having a diverse diet.{{Cite journal |last1=Trinajstic |first1=Kate |last2=Briggs |first2=Derek E. G. |last3=Long |first3=John A. |date=23 November 2021 |title=The Gogo Formation Lagerstätte: a view of Australia's first great barrier reef |journal=Journal of the Geological Society |volume=179 |issue=1 |issn=0016-7649 |doi=10.1144/jgs2021-105 |doi-access=free }} Fossils have been found in numbers, suggesting possible schooling behavior.

Phylogeny

Compagopiscis was originally classified as a member of the family Plourdosteidae.{{Cite journal |last1=Carr |first1=R.K. |last2=Hlavin |first2=W.J. |title=Two new species of Dunkleosteus Lehman, 1956, from the Ohio Shale Formation (USA, Famennian) and the Kettle Point Formation (Canada, Upper Devonian), and a cladistic analysis of the Eubrachythoraci (Placodermi, Arthrodira) |journal=Zoological Journal of the Linnean Society |volume=159 |issue=1 |pages=195–222 |year=2010 |doi=10.1111/j.1096-3642.2009.00578.x |doi-access=free }} However, phylogenetic analysis later found Plourdosteidae to be an invalid grouping, and the family was dismissed.{{Cite journal |author1=You-An Zhu |author2=Min Zhu |title=A redescription of Kiangyousteus yohii (Arthrodira: Eubrachythoraci) from the Middle Devonian of China, with remarks on the systematics of the Eubrachythoraci | journal=Zoological Journal of the Linnean Society |volume=169 |issue=4 |pages=798–819 |year=2013 |doi=10.1111/zoj12089 |doi-access= }} Torosteus is now considered to be a member of the superfamily Incisoscutoidea, which belongs to the clade Coccosteomorphi, one of the two major clades within Eubrachythoraci. The cladogram below shows the phylogeny of Compagopiscis:{{Cite journal |last1=Zhu |first1=You-An |last2=Zhu |first2=Min |last3=Wang |first3=Jun-Qing |date=1 April 2016 |title=Redescription of Yinostius major (Arthrodira: Heterostiidae) from the Lower Devonian of China, and the interrelationships of Brachythoraci |journal=Zoological Journal of the Linnean Society |volume=176 |issue=4 |pages=806–834 |doi=10.1111/zoj.12356|issn=0024-4082 |doi-access=free }}