But wait,
Squalodontidae or the
shark-toothed dolphins is an extinct family of large
toothed whales who had long narrow jaws.
[2]Squalodontids are known from all continents except Antarctica, from the
Oligocene to the
Neogene, but they had a maximal diversity and global distribution during the Late Oligocene and Early to Middle
Miocene (
28 to 15 mya).
[2][1]
With their cosmopolitan Miocene distribution and
heterodont dentition, squalodontids are the most common and basal platanistoids. They are relatively large odontocetes, comparable in size to extant
mesoplodont whales. The
premaxillae on their elongated
rostrumhave large and slightly convex fossae for the air sacs associated with the presence of a
melon, indicating the ability for echolocation.
[3]
They are proposed as the first whales to have possessed melons, or air sacs associated with the presence of such.