''Serenoichthys'' is an

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

of small

bichir Bichirs and the reedfish comprise Polypteridae , a family of archaic ray-finned fishes and the only family in the order Polypteriformes .Helfman GS, Collette BB, Facey DE, Bowen BW. 2009. The Diversity of Fishes. West Sussex, UK: Blackwell Pub ...

from the

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', the ...

(

Cenomanian The Cenomanian is, in the ICS' geological timescale, the oldest or earliest age of the Late Cretaceous Epoch or the lowest stage of the Upper Cretaceous Series. An age is a unit of geochronology; it is a unit of time; the stage is a unit in the s ...

) of southeastern

Morocco Morocco (),, ) officially the Kingdom of Morocco, is the westernmost country in the Maghreb region of North Africa. It overlooks the Mediterranean Sea to the north and the Atlantic Ocean to the west, and has land borders with Algeria to ...

. The genus is monotypic, the type and only species being ''Serenoichthys kemkemensis''. Only known at first from postcranial skeletons, complete specimens were later discovered.

Etymology

The generic name ''Serenoichthys'' (Sereno's fish) was given after the leader of the team responsible for the discovery, Paul C. Sereno. The species name, ''kemkemensis'', refers to the

Kem Kem The Kem Kem Group (commonly known as the Kem Kem beds) is a geological group in the Kem Kem region of eastern Morocco, whose strata date back to the Cenomanian stage of the Late Cretaceous. Its strata are subdivided into two geological formations ...

locality in

where the fossils were discovered.

Description

''Serenoichthys'' was comparatively small, with the fossils discovered reaching at most in length — in comparaison, the contemporary polypterid '' Bawitius'' could reach up to . Its body was relatively short and tall compared to modern polypterids, closer to the original actinopterygian body plan. Like modern-day polypterids, ''Serenoichthys'' possessed a dorsal fin divided into a series of independent finlets each supported by a spine, a defining

synapomorphy In phylogenetics, an apomorphy (or derived trait) is a novel character or character state that has evolved from its ancestral form (or plesiomorphy). A synapomorphy is an apomorphy shared by two or more taxa and is therefore hypothesized to have ...

of the

Cladistia Cladistia is a clade of bony fishes whose only living members are the bichirs. Their major synapomorphies are a heterocercal tail in which the dorsal fin has independent rays, and a posteriorly elongated parasphenoid. Cladistia are the earlie ...

References

Polypteridae Prehistoric ray-finned fish genera Cretaceous bony fish Prehistoric fish of Africa Fossil taxa described in 1999 {{paleo-rayfinned-fish-stub