The syncranial osteology of the southern eel-cod family Muraenolepididae, with comments on its phylogenetic relationships and on the biogeography of sub-Antarctic gadoid fishes



The monogeneric gadoid family Muraenolepididae has been neglected both taxonomically and anatomically. Without good evidence it has been the opinion of most authors that the family possesses mainly primitive features. A comparison of the syncranial osteology with that of other taxa shows that this can be refuted and that Muraenolepis is a relatively derived ‘higher’ gadoid, having its relationships close to the Phycidae and Gadidae. The circum-Antarctic distribution of Muraenolepis is unique within gadoids and poses the question of its origin. This is discussed with reference to bipolar distributions exhibited by some other gadoid families. It is concluded that gadoids have evolved with the Atlantic continental shelves and their distribution (and bipolarity) is a consequence of the geological processes which have formed the Atlantic Ocean.