A new oligo-miocene dolphin from New Zealand: Otekaikea huata expands diversity of the early Platanistoidea

Abstract

The New Zealand fossil dolphin Otekaikea huata (latest Oligocene to earliest Miocene, in the range 22.28 to 24.61 Ma) is here identified as an early new species in the clade Platanistoidea, which includes the endangered Ganges River dolphin (Platanista gangetica). Otekaikea huata is known only from the holotype, which comprises a partial skeleton from the marine Otekaike Limestone of the Hakataramea Valley, South Island. Otekaikea huata has multiple procumbent tusks passing back to otherwise near-homodont and polydont teeth, and an elevated face for the nasofacial muscles implicated in production of echolocation sounds. The skull vertex is asymmetrical and strongly left-skewed. Phylogenetic analyses based on morphological features place Otekaikea huata in the clade Platanistoidea. The new species adds to the diversity of the superfamily Platanistoidea near the Oligocene-Miocene boundary.