http://www.berkeley.edu/news/media/releases/2007/09/05_WhaleSonar.shtml
Structures involved in echolocation
(see article for details and credits)
Behind the sailor’s lore of fearsome battles between sperm whale and giant squid lies a deep question of evolution: How did these leviathans develop the underwater sonar needed to chase and catch squid in the inky depths?
This article has some answers to the questions.
