The fossil shark Ptychodus was first identified 190 years ago, but in the intervening centuries of paleontological inquiry, a comprehensive look at the ancient fish has been hard to come by. Until now.
O. megalodon, my megalodon. The gargantuan shark that prowled the Miocene seas has long captured the imagination because of its stupendous 60-foot length—three times the size of the largest great white sharks. But now, a team of researchers suggests that the extinct apex predator’s body shape was slightly different…