On Prophoca and Leptophoca (Pinnipedia, Phocidae) from the Miocene of the North Atlantic realm: redescription, phylogenetic affinities and paleobiogeographic implications

• Published in: PeerJ (San Francisco, CA) CA), 2017-02, Vol.5, p.e3024-e3024, Article e3024
• Main Authors: Dewaele, Leonard, Lambert, Olivier, Louwye, Stephen
• Format: Article
• Language: English
• Subjects: Analysis; Biostratigraphy; Dispersal; Endangered & extinct species; Evolutionary Studies; Fossils; Identification and classification; Leptophoca; Miocene; Museums; Natural history; New combinations; North Atlantic; Paleontology; Phocidae; Phylogenetics; Phylogeny; Prophoca; Provenance; Redescription; Seals (Animals); Stratigraphy; Taxonomy; Zoology
• ISSN: 2167-8359; 2167-8359
• DOI: 10.7717/peerj.3024

and represent the oldest known genera of phocine seals, dating from the latest early to middle Miocene. Originally, and were described based on fragmentary remains from the Miocene of Belgium. However, several researchers contested the union of and into one genus, without providing evidence. The stratigraphic context of remained poorly constrained due to the lack of precise data associated with the original specimens collected in the area of Antwerp (north of Belgium). and are redescribed and their phylogenetic position among Phocidae is reassessed using PAUP. Dinoflagellate biostratigraphy has been carried out on sediment samples associated with specimens from and to elucidate their approximate ages. Whereas the species is redescribed, is considered synonymous to , with the proposal of a new combination (Van Beneden, 1877). Sediment samples from specimens of both taxa have been dated to the late Langhian-early Serravallian (middle Miocene). Following a reinvestigation of , characters from the original diagnosis are questioned and the specimens of are considered cf. . In a phylogenetic analysis, and constitute early branching stem-phocines. from the North Sea Basin is younger than the oldest known find of from North America, which does not contradict the hypothesis that Phocinae originated along the east coast of North America during the late early Miocene, followed by dispersal to Europe shortly after. Morphological features of the appendicular skeleton indicate that and have archaic locomotory modes, retaining a more prominent use of the fore flipper for aquatic propulsion than extant Phocidae.