Jillian is one of the good ones, and this is really nice.
Blog about "The World's best Shark Dive" by Beqa Adventure Divers. Featuring up to eight regular species of Sharks and over 400 different species of fish, Shark diving doesn't get any better!
My theory is: Hammers are about 5 million years old – young for sharks, and the winghead and great hammer are the oldest species of the hammers, and they also have the biggest heads. The younger species have much more reduced heads, so Im guessing that hammers as a group first developed this big ole head, which is great for hunting, and a big dorsal to also help with maneuvering while hunting – but then realised that this head is actually pretty shit for cruising about (not efficient). Hey, but when I swim on my side that works much better.
Then as the newer species evolved, the head is reduced – a tradeoff between the hunting benefits and transport.