protocetid

As nouns the difference between terms and protocetid

is that terms is while protocetid is any of a group of extinct cetaceans, of the family , from the eocene period.

As an adjective Eocene

is of a geologic epoch within the Paleogene period from about 56 to 34 million years ago.

As a proper noun Eocene

is the Eocene epoch.

As a noun protocetid is

any of a group of extinct cetaceans, of the family family: Protocetidae, from the Eocene period.

As nouns the difference between cetacean and protocetid

is that cetacean is an animal belonging to the order cetacea, including dolphins, porpoises, and whales while protocetid is any of a group of extinct cetaceans, of the family , from the eocene period.

As an adjective cetacean

is pertaining to the zoologic order cetacea, or associated with species falling under that taxonomic hierarchy.

As an adjective extinct

is (dated) extinguished, no longer alight (of fire, candles etc).

As a noun protocetid is

any of a group of extinct cetaceans, of the family , from the eocene period.