An Early Triassic basal actinopterygian fish (Osteichthyes) from D'Urville Island, New Zealand

A small partial actinopterygian (ray-finned) fish from the Lower Triassic Greville Formation of D'Urville Island is reported as the first formally noted and described Triassic actinopterygian from New Zealand. The specimen includes the upper lobe of a slender heterocercal caudal fin, with fringing fulcra and a series of dorsal caudal fulcra and epaxial basal fulcra. The fossil also preserves additional fin rays and a series of probable neural and haemal arch elements. The fossil is too incomplete to be precisely identified, but the heterocercal caudal fin with associated fringing and dorsal caudal fulcra are sufficient to diagnose the specimen as a phylogenetically basal 'palaeoniscoid'-grade actinopterygian, the first to be reported from New Zealand.