New Billfish Fossils (Percomorpha: Xiphioidei) from Fossil Point, South Island, New Zealand, and a Review of the Marine Vertebrate Fauna from the Oligocene Abel Head Formation

Abstract

<p>New vertebrate fossil material was recovered from the Abel Head Formation (Oligocene), Fossil Point, South Island New Zealand. Fossils within concretionary blocks (CMC ZFp1218 A and B) were analysed using neutron tomography scanning and described using the 3D models segmented from the scans. A single large vertebrae (CMC ZFp1219) was described using more traditional methods and neutron tomography scanning was not required. The fossils within concretions CMC ZFp1218 A and B are identified as Xiphioidei gen. et sp. indet (billfish) and the single large vertebrae CMC ZFp1219 is identified as Cetacea gen. et sp. indet (whale). Prior to the newly described material, there was only a single vertebrate fossil occurrence from the Abel Head Formation, cetacean; <i>Austrosqualodon trirhizodonta</i>, and some invertebrates. The new Abel Head Formation material provides a greater sense of what the faunal components of the Formation are, and the new billfish material is comparable to another Xiphioidei within the Otekaike Limestone (Oligocene – Miocene). The Abel Head Formation was deposited in a period of New Zealand’s prehistory a time that contesting theories claim it was either near or totally submerged by seas, the more complete our understanding of Oligocene deposits like the Abel Head Formation is, the more complete our image of New Zealand’s prehistory will be.</p>