''Macrodelphinus'' is an extinct genus of primitive odontocete known from Late

Oligocene The Oligocene ( ) is a geologic epoch of the Paleogene Period and extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that define the epoch are well identified but the ...

(

Chattian The Chattian is, in the geologic timescale, the younger of two ages or upper of two stages of the Oligocene Epoch/Series. It spans the time between . The Chattian is preceded by the Rupelian and is followed by the Aquitanian (the lowest stage ...

) marine deposits in California.

Biology

''Macrodelphinus'' was an

orca The orca or killer whale (''Orcinus orca'') is a toothed whale belonging to the oceanic dolphin family, of which it is the largest member. It is the only Extant taxon, extant species in the genus ''Orcinus'' and is recognizable by its black ...

-sized odontocete similar to members of

Eurhinodelphinidae Eurhinodelphinidae is an extinct Family (biology), family of toothed whales which lived from the Oligocene to the Miocene. Members of the family possessed an elongated jaw similar in appearance to a swordfish. Taxonomy *Family Eurhinodelphinid ...

in having a swordfish-like rostrum and upper jaw. Because of its size, and inch-long teeth, it is believed to have been an apex predator.

Classification

''Macrodelphinus'' is known from a fragmentary skull from the Late Oligocene Jewett Sand Formation of Kern County, southern California. Although often classified as a member of Eurhinodelphinidae, the cladistic analysis of '' Chilcacetus'' recovers it outside Eurhinodelphinidae, less advanced than '' Eoplatanista''. The Miocene species ''"Champsodelphis" valenciennesii'' Brandt, 1873, based on a rostrum fragment from marine sediments in Landes, France, was assigned to ''Macrodelphinus'' by Kellogg (1944).R. Kellogg. 1944. Fossil Cetaceans from the Florida Tertiary. Bulletin of the Museum of Comparative Zoology at Harvard College XCIV(9):433-471.

References

* Miocene mammals of North America Prehistoric toothed whales Miocene cetaceans Prehistoric cetacean genera Fossil taxa described in 1935 {{paleo-whale-stub