Calamopleurus

{{Short description|Extinct genus of ray-finned fishes}}

{{Automatic taxobox

| fossil_range = {{Fossil range|136.4|100|Late Hauterivian to Early Cenomanian}}

| image = Calamopleurus cylindricus MHNT.jpg

| image_caption = Calamopleurus cylindricus

| taxon = Calamopleurus

| authority = Agassiz, 1841

| type_species = Calamopleurus cylindricus

| type_species_authority = Agassiz, 1841

| subdivision_ranks = Species

| subdivision = See text

}}

Calamopleurus is a prehistoric genus of marine halecomorph ray-finned fish from the Early Cretaceous of South America and northern Africa. It was a relative of the modern bowfin, with both belonging to the family Amiidae.{{Cite web |title=PBDB Taxon |url=https://paleobiodb.org/classic/basicTaxonInfo?taxon_no=149774 |access-date=2024-04-16 |website=paleobiodb.org}}

It contains three species:{{cite journal |author=Peter L. Forey & Lance Grande |year=1998 |title=An African twin to the Brazilian Calamopleurus (Actinopterygii: Amiidae) |journal=Zoological Journal of the Linnean Society |volume=123 |issue=2 |pages=179–195 |doi=10.1111/j.1096-3642.1998.tb01299.x |doi-access=free}}{{Cite journal |last1=Brito |first1=Paulo M. |last2=Nava |first2=William R. |last3=Martinelli |first3=Agustin G. |date=2017-09-01 |title=A New Fossil Amiidae (Holostei: Halecomorphi) from the Upper Cretaceous Adamantina Formation, Southeastern Brazil, with comments on western Gondwana amiids |url=https://www.sciencedirect.com/science/article/pii/S0195667117300083 |journal=Cretaceous Research |volume=77 |pages=39–43 |doi=10.1016/j.cretres.2017.04.018 |bibcode=2017CrRes..77...39B |issn=0195-6671|url-access=subscription }}

• †C. africanus Forey & Grande, 1998 - Late Albian/Early Cenomanian of Morocco and Algeria{{Cite journal |last1=Benyoucef |first1=Madani |last2=Läng |first2=Emilie |last3=Cavin |first3=Lionel |last4=Mebarki |first4=Kaddour |last5=Adaci |first5=Mohammed |last6=Bensalah |first6=Mustapha |date=2015 |title=Overabundance of piscivorous dinosaurs (Theropoda: Spinosauridae) in the mid-Cretaceous of North Africa: The Algerian dilemma |url=https://www.researchgate.net/publication/272846349 |journal=Cretaceous Research |volume=55 |pages=44–55 |doi=10.1016/j.cretres.2015.02.002 |bibcode=2015CrRes..55...44B |issn=0195-6671}}
• †C. cylindricus Agassiz, 1841 - Late Aptian/Early Albian of Brazil (Crato and Santana Formations)
• †C. mawsoni Woodward, 1902 - Late Hauterivian/Early Barremian of Brazil (Bahia Group)

It is thought to be the sister genus to Maliamia, the last surviving member of the vidalamiines, which is the largely marine amiid group that also contained Calamopleurus. Both are placed in the tribe Calamopleurini.

File:Calamopleurus with Vinctifer lodged in pharynx (cropped).jpg lodged in the pharynx.]]

File:Calamopleurus e Rhacolepis.jpg]]

C. cylindricus was among the largest known amiids, rivaling the giant Paleocene bowfin Amia pattersoni in size. However, both were slightly smaller than Melvius and Amia basiloides, the two largest known amiids. It is one of the earliest known amiids to evolve a large body size.{{Cite web |last=Brownstein |first=Chase D. |last2=Near |first2=Thomas J. |date=2024 |title=A giant bowfin from a Paleocene hothouse ecosystem in North America |url=https://academic.oup.com/zoolinnean/advance-article-abstract/doi/10.1093/zoolinnean/zlae042/7659736 |access-date=2024-04-30 |website=academic.oup.com |doi=10.1093/zoolinnean/zlae042/7659736}}