Anatomy and phylogeny of the large shark-toothed dolphin Phoberodon arctirostris Cabrera, 1926 (Cetacea, Odontoceti) from the early Miocene of Patagonia (Argentina)

M.VIGLINO; J.CUITIÑO; R. E. FORDYCE; M. BUONO; E. FITZGERALD

ZOOLOGICAL JOURNAL OF THE LINNEAN SOCIETY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2018 vol. 185 p. 511 - 542

0024-4082

The early Miocene of Patagonia (Argentina) provides one of the best-known records of odontocetes for an age interval with scarce fossils. Most of these taxa are historically old and briefly described, which has partly contributed to their controversial taxonomic position. The shark-toothed dolphin Phoberodon arctirostris was described almost a hundred years ago, and suggested as a member of Platanistoidea, and also a Squalodontidae. However, it has not been recently analyzed and has never been included in a phylogenetic analysis. Recent field work in the early Miocene sediments in Patagonia yielded a new specimen referred to this species, allowing for its modern and detailed description and first phylogenetic analyses. Analyses recovered Phoberodon arctirostris as a stem Odontoceti or an early-diverging platanistoid, more closely related to an unnamed Oligocene specimen from New Zealand and not in a clade with Squalodon calvertensis (i.e. Squalodontidae). The reconstructed body length of Phoberodon arctirostris indicates that it is one of the largest stem Odontoceti. Our results suggest that during the early Miocene of Patagonia, archaic odontocete forms (i.e. Phoberodon arctirostris) cohabited along with archaic and more-crownward platanistoids (i.e. Aondelphis talen and Notocetus vanbenedeni), helping characterize the early Miocene cetacean communities of Patagonia.