A diverse assemblage of pycnodont fishes (Actinopterygii, Pycnodontiformes) from the mid-Cretaceous, continental Kem Kem Group of south-east Morocco

Pycnodont fishes (Actinopterygii, Pycnodontiformes) contributed a major role to many ichthyological assemblages in the Mesozoic, however their occurrence in the continental mid-Cretaceous Kem Kem Group of Morocco was only briefly noted by Sereno et al., 1996, but were not described. Here we describe the first diverse pycnodont assemblage in the Kem Kem beds of the Tafilalt region, based mainly on recent collecting. Pycnodont remains are represented by rare, mostly incomplete fragments of vomerine and prearticular dentitions, but despite their rarity, they are surprisingly diverse with four morphotypes represented, including two new taxa: Neoproscinetes africanus sp. nov. and Agassizilia gen. nov. From a sample of eight specimens, four species are recorded, three of which are new. The palaeoecology, taphonomy and biostratinomy of the specimens is discussed in the context of their occurrence in a predominantly freshwater sequence. Comparisons are made with the pycnodont assemblage of the approximately coeval Santana Group (Brazil) which contains taxa with similarities to the new Moroccan pycnodonts. These new pycnodont taxa increase the already diverse assemblage of the Kem Kem Group ichthyofauna.