Scaldiporia vandokkumi, a new pontoporiid (Mammalia, Cetacea, Odontoceti) from the Late Miocene to earliest Pliocene of the Westerschelde estuary (The Netherlands)

• Published in: PeerJ
• Main Authors: Post, Klaas, Louwye, Stephen, Lambert, Oliver
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2017
• Subjects: Biology and Life Sciences; Earth and Environmental Sciences; Cetacea; Inioidea; Pontoporiidae; Westerschelde; The Netherlands; Late Miocene; earliest Pliocene; EASTERN NORTH-ATLANTIC; DINOFLAGELLATE CYST; DOLPHIN CETACEA; PISCO FORMATION; INIOID CETACEA; MIDDLE MIOCENE; NEOGENE; RECORD; OCEAN; BASIN; Argentina; Uruguay; Pisco; North Atlantic
• Online Access: https://biblio.ugent.be/publication/8538192; http://hdl.handle.net/1854/LU-8538192; https://doi.org/10.7717/peerj.3991; https://biblio.ugent.be/publication/8538192/file/8538197

Background. The family Pontoporiidae (Cetacea, Odontoceti Inioidea) is currently represented in our oceans by just one species of diminutive dolphin (Pontoporia blainvillei, franciscana). Although P. blainvillei is limited to coastal waters of the South Atlantic along Brazil, Uruguay and Argentina, multiple Miocene and Pliocene fossils indicate the past presence of members of the family in the South Atlantic, South Paciifc and North Atlantic oceans. Our comprehension of the origin and diversity of this clade and of the relationships of its members with other inioids is hampered by the fact that part of the described fossil specimens, especially from the North Atlantic realm, are cranial fragments often associated to limited stratigraphic information. Methods. Based on an almost complete fossil cranium of pontoporiid from the Westerschelde estuary, The Netherlands, whose preservation allows for detailed morphological observations, we describe a new genus and species. The latter is compared to other pontoporiids, as well as 'a few non-pontoporiid inioids. A phylogenetic analysis is performed to investigate the relationship of S. vandokkumi with the best-known extinct and extant inioids. Palynological analysis of the sediment associated to the holotype is used to assess its geological age. Results and discussion. The new genus and species Scaldiporia vandokkurni is characterized among others by greatly thickened premaxillary eminences reaching the level of the antorbital notch. Palynologically dated from the late Tortonian earliest Zanclean (7,6-5 Ma, Late Miocene earliest Pliocene), this new pontoporiid confirms the surprising past diversity of marine inioids in the North Atlantic area. Finally the content of the pontoporiid subfamily Brachydelphininae is briefly discussed