Ancient DNA analysis of an archaeological assemblage of Chondrichthyes vertebrae from South Auckland, New Zealand

Sharks and their relatives (Chondrichthyes) were an important food source for pre-European Māori. However, their skeletons, which are largely comprised of cartilage, are poorly preserved in the archaeological record, with only teeth and vertebrae routinely recorded. Furthermore, it is often difficult to identify Chondrichthyes by their vertebral morphology. Here we compare the morphological and ancient DNA identification of 180 Chondrichthyes vertebrae representing seven different morphotypes sampled from a large archaeological assemblage in Auckland, New Zealand. aDNA sequences were obtained from 87 vertebrae and indicated the presence of four Chondrichthyes species at the site: rig (Mustelus lenticulatus), school shark (Galeorhinus galeus), bronze whaler (Carcharhinus brachyurus) and New Zealand eagle ray (Myliobatis tenuicaudatus). The aDNA results indicated several instances where morphological identification of vertebrae had been incorrect, including the most common taxon found in the assemblage, rig, which had been identified morphologically as school shark. Overall, our results indicated that aDNA analysis of Chondrichthyes vertebrae is a valuable tool to distinguish between specimens with morphologically similar vertebrae and to verify morphological identifications.