Phylogenetic relationships of fossil and Recent gonorynchiform fishes (Teleostei : Ostariophysi)

This paper represents the first cladistic analysis of the interrelationship s of all nominal fossil and living gonorynchiform genera. Gonorynchiformes is the basal group of the superorder Ostariophysi, and is confirmed as mono phyletic on the basis of 12 synapomorphies. The Gonorynchiformes is be subd ivided into two monophyletic suborders, Chanoidei and Gonorynchoidei. The C hanoidei includes the family Chanidae, which in turn includes the Recent Ch anos plus five fossil genera, grouped in two subfamilies: Chaninae ((Chanos + dagger Tharrilias) + dagger Parachanos + dagger Dastilbe) and dagger Rub iesichthyinae (dagger Rubiesichthys + dagger Gordichthys). dagger Aethalion opsis is the sister-group to the Chanidae. Gonorynchoidei includes two fami lies Gonorynchidae and Kneriidae. Gonorynchidae is formed by (Gonorynchus, dagger Notogoneus) and four fossil taxa of uncertain definition and interre lationships: dagger Charitosomus, dagger Charitopsis, dagger Ramallichthys, and dagger Judeichthys. The last four genera were previously included in t he families dagger Charitosomidae and dagger Judeichthyidae, which could no t be supported as monophyletic in this analysis. Kneriidae consists of two subfamilies Phractolaeminae with one genus Phractolaemus, and Kneriinae whi ch includes ((Kneria + Parakneria) + (Grasseichthys + Cromeria)), the latte r two being paedomorphic forms. The Phractolaeminae and the Kneriinae are f reshwater African taxa with no known fossil record. The order Gonorynchifor mes is represented herein by 18 genera, extending back to the Early Cretace ous. More work is required to clarify the interrelationships of the Gonoryn chidae and the paedomorphic characters that apparently played an important role in the evolution of this morphologically diverse group of fishes. (C) 1999 The Linnean Society of London.