''Eodelphinus'' is an extinct genus of oceanic dolphins belonging to the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Delphinidae Oceanic dolphins or Delphinidae are a widely distributed family of dolphins that live in the sea. Close to forty extant species are recognised. They include several big species whose common names contain "whale" rather than "dolphin", such as the ...

Description

''Eodelphinus'' differs from all other delphinids by having a medially positioned premaxillary foramen, a partially transversely directed suture line between the palatine and pterygoid on the palate, and prominently long and ventrolaterally extended posterior process of the periotic with the attenuating posterior bullar facet. It possesses a wide ascending process of the left premaxilla relative to the right premaxilla at level of the middle of the external nares as in the

killer whale The orca (''Orcinus orca''), or killer whale, is a toothed whale and the largest member of the oceanic dolphin family. The only extant species in the genus '' Orcinus'', it is recognizable by its black-and-white-patterned body. A cosmopolit ...

and '' Hemisyntrachelus''.

Taxonomy

''Eodelphinus'' was originally described in 1977 as a new species of ''

Stenella ''Stenella'' is a genus of marine mammals in Delphinidae, the family (biology), family informally known as the oceanic dolphins. Species Currently, five species are recognised in this genus: ''S. rayi'' was a species of this genus found in N ...

'', ''S. kabatensis'', from a partial skull found in marine deposits in

Hokkaido is the list of islands of Japan by area, second-largest island of Japan and comprises the largest and northernmost prefectures of Japan, prefecture, making up its own list of regions of Japan, region. The Tsugaru Strait separates Hokkaidō fr ...

, Japan. Later, Ichisima (2005) questioned the attribution of ''S. kabatensis'' to ''Stenella'', stressing the need for re-assessment of the taxon. Subsequent study by Mizuki Murakami and colleagues published in 2014 showed that ''S. kabatensis'' is the most basal member of

, necessitating erection of the new genus ''Eodelphis''.M. Murakami, C. Shimada, Y. Hikidad, Y. Soedae, and H. Hirano. 2014. Eodelphis kabatensis, a new name for the oldest true dolphin Stenella kabatensis Horikawa, 1977 (Cetacea, Odontoceti, Delphinidae), from the upper Miocene of Japan, and the phylogeny and paleobiogeography of Delphinoidea. Journal of Vertebrate Paleontology 34(3):491-511 However, the genus name was changed to ''Eodelphinus'' because ''Eodelphis'' was already used for a fossil opossum.M. Murakami, C. Shimada, Y. Hikida and Y. Soeda. 2014. Eodelphinus kabatensis, a replacement name for Eodelphis kabatensis (Cetacea: Delphinoidea: Delphinidae). Journal of Vertebrate Paleontology 34(5):1261

References

{{Taxonbar, from=Q55610943 Oceanic dolphins Fossil taxa described in 2014