A new Eomysticetid ( Mammalia: Cetacea) from the Late Oligocene of New Zealand and a re‐evaluation of ‘ Mauicetus’ waitakiensis

• Published in: Papers in Palaeontology
• Main Authors: Boessenecker, Robert W., Fordyce, R. Ewan
• Other Authors: O'Regan, Hannah, University of Otago Doctoral Scholarship, National Geographic Society
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2014
• Subjects: baleen whales
• Online Access: http://dx.doi.org/10.1002/spp2.1005; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fspp2.1005; https://onlinelibrary.wiley.com/doi/pdf/10.1002/spp2.1005

Abstract The published O ligocene record of mysticetes (baleen whales) is dominated by toothed mysticetes in addition to the Eomysticetidae, the earliest known chaeomysticetes known only from the O ligocene. Formally recognized eomysticetids include examples from the O ligocene of S outh C arolina, USA ( E omysticetus ), and J apan ( Y amatocetus ). A new fossil from the upper O ligocene O tekaike L imestone including a partial skull, periotic, tympanic bulla, mandible and some postcrania is here described as T ohoraata raekohao gen. et sp. nov. T ohoraata confirms the presence of an eomysticetid in N ew Z ealand. T ohoraata raekohao is characterized by delicate frontal with numerous supraorbital foramina and sulci, relatively long exposure of the frontal and parietal along a transversely narrow intertemporal region, greatly enlarged temporal fossa, massive and anteriorly directed zygomatic process lacking a supramastoid crest, and a periotic with superior process reduced to a low ridge with anterior and posterior apices. Cranial and postcranial fusion of elements, development of muscle attachments and osteohistology demonstrate that the T . raekohao holotype is an adult or possible subadult. Features of the tympanic bulla including a relatively wide bulla with a medial lobe that is transversely much wider than the lateral lobe, and a slightly posterolaterally facing exoccipital, permit referral of the fragmentary ‘ M auicetus’ waitakiensis of M arples into the genus T ohoraata , resulting in T ohoraata waitakiensis comb. nov. Description of T . raekohao and resolution of the relationships of the hitherto problematic T ohoraata waitakiensis indicates that several eomysticetids were present in the S outhern O cean during the L ate O ligocene.