A peculiar diplospondylous actinopterygian fish from the Cretaceous of Morocco

Abstract

ABSTRACT Diplospondichthys moreaui, gen. et. sp. nov. a freshwater fish from the Cenomanian of Morocco, is described. The fish is complete and articulated but only a few elements of the head are perfectly preserved. Therefore, the new taxon's relationships are essentially based on its very peculiar axial skeleton. Although we believe that the fish is probably a teleost, it displays such a strange combination of characters that we propose herein to classify it as an actinopterygian incertae sedis. The presence of pharyngeal teeth, diplospondylous and well-ossified vertebrae throughout the column, spine-bearing scutes on both sides of the body, and unpaired elements articulating with neural and haemal spines, are some of its unusual features. We believe that this fish could be of primary importance to understand the evolution of the axial skeleton in osteichthyans.