-idae, -ida, -id

(Greek: a suffix used to form the names of families in zoology and biology; descended from, related to)

Agorophiidae
Archaic dolphins supposedly the most ancient or basal odontocetes (toothed whales, a suborder of the cetaceans).

As the name suggests, the suborder is characterized by having teeth (rather than baleen as do animals in the other suborder of cetaceans, Mysticeti. Toothed whales are active hunters, feeding on fish, squid, and in some cases marine mammals.

Balaenidae
Balaenopteridae
Basilosauridae
Delphinidae
Eschrichtiidae
Mesonychidae
"Middle Claws", an extinct family of medium to large-sized omnivorous-carnivorous mammals closely related to artiodactyls (even-toed ungulates) which existed in North America and Eurasia over 33 million years ago.
Monodontidae
Platanistidae