Awadelphis

{{Short description|Extinct species of dolphin}}

{{speciesbox

| fossil_range = Late Miocene 6.3–5.7 Ma

| genus = Awadelphis

| parent_authority = Murakami, 2016

| species = hirayamai

| authority = Murakami, 2016

| display_parents = 3

}}

Awadelphis hirayamai is a species of extinct oceanic river dolphin discovered in the Senhata Formation of Japan dating around 6 million years ago (mya). The genus name derives from Awa, an ancient name for the Chiba Prefecture where the holotype specimen was collected, and Ancient Greek delphis meaning "dolphin"; the species name honors the discoverer of the holotype, Ren Hirayama. It may have inhabited a subpolar environment. Awadelphis and other river dolphins of the Late Miocene may have been in abundance due to the decline of competing ancient dolphins and porpoises.{{cite journal|first=M.|last=Murakami|year=2016|title=A New Extinct Inioid (Cetacea, Odontoceti) from the Upper Miocene Senhata Formation, Chiba, Central Japan: The First Record of Inioidea from the North Pacific Ocean|journal=Paleontological Research|volume=20|issue=3|pages=207–225|doi=10.2517/2015PR031|s2cid=132209924}}