POLYPTERUS EVO-DEVO · Polypterids – development and evolution of a ’living fossil’

Polypterids or bichirs are a small group of African freshwater fishes often regarded as 'living fossils' because of their large number of primitive characters. Bichirs form the most basal branch of extant actinopterygians and have played an outstanding role in any study on the evolution of the major vertebrate clades. As a first step towards a modern treatment of these extraordinary ray-finned fishes, the present project will provide an up-to-date taxonomic analysis of the family Polypteridae incorporating for the first time all major museum holdings in Europe and the rest of the world. In a second step the phylogenetic relationships of all polypterid species will be analysed using state-of-the-art morphological and molecular methods. The core of the proposed project will comprise a detailed description and analysis of polypterid skeletal ontogeny, based on complete developmental series of the two extant genera Polypterus and Erpetoichthys, which are unique in the world. Characters relevant for the phylogenetic placement of polypterids among gnathostomes will be reevaluated from an ontogenetic point of view. This part of the study will also address important question of skeletal homology among basal osteognathostomes and aid in their resolution. The results will form an important reference for future studies on the comparative anatomy and phylogeny of basal vertebrate groups, as well as developmental genetic studies searching for the basal pattern of vertebrate development.