Papahu-like fossil dolphin from Kaikoura, New Zealand, helps to fill the Early Miocene gap in the history of Odontoceti

An early Miocene dolphin (ZMT 73: partial skull and ear bones) from Kaikoura, New Zealand, is the sister taxon to the previously named Early Miocene Papahu taitapu. The new specimen, although insufficient to justify a new species name, includes an informative squamosal and periotic that help move the Papahu clade from the stem Odontoceti to either the Platanistoidea, or to become the sister taxon to the Ziphiidae+Eurhinodelphinidae+Delphinida. The fossils usefully add to the taxonomic and structural diversity of Cetacea during the important but poorly known Early Miocene.

产自新西兰凯库拉（Kaikoura）的早中新世海豚标本（ZMT 73：部分头骨与耳骨），是此前命名的早中新世Papahu taitapu的姊妹分类群。该新标本虽不足以确立新种学名，但包含一块具重要研究价值的鳞状骨与围耳骨，相关材料可帮助将Papahu演化支从基干齿鲸类（stem Odontoceti）归入恒河豚总科（Platanistoidea），或是作为剑吻鲸科（Ziphiidae）+长吻海豚科（Eurhinodelphinidae）+海豚下目（Delphinida）的姊妹群。这些化石有效补充了鲸目（Cetacea）在这一意义重大但研究程度较低的早中新世时期的分类与形态结构多样性。