toothless whale

Whales with teeth are usually thought to have split off in evolution about 40 million years ago from toothless whales that use a fibrous material called baleen to strain food from water.

Two Types, One Family The toothless whales, which have very different bodies than the toothed ones and do not use echolocation for hunting, were thought to be on a distinct evolutionary branch.

As far as we know, baleen whales, toothless whales like the humpbacks who strain their food from the sea through sheets of baleen, don't echolocate the way toothed whales do.

The toothless whales are called baleens for the feeding apparatus in their jaw, a huge sieve of whalebone through which they filter shrimplike krill and tiny fish from the huge amounts of sea water they gulp.