巨齿鲨_史上最大的鲨鱼.pptVIP

巨齿鲨史上最大的鲨鱼MegalodonThe Largest Shark that Ever Lived Megalodon Exhibit Background Will be open at the Florida Museum of Natural History from June 16th – Dec. 31st 2007. Focal point of the exhibit is a 60-foot model of a Megalodon shark that visitors will be able to walk through. Dr. Bruce MacFadden and Bob Purdy discussing the plans If Shark Teeth Could Talk Shark teeth can: Identify the species Lemon Shark Mako Shark If Shark Teeth Could Talk Shark teeth can: Sometimes indicate body size Megalodon Whale Shark If Shark Teeth Could Talk Shark teeth can: Indicate prey or prey size Great White Shark Basking Shark This Was One Big Shark! Scientists still debate Carcharodon (or Carcharocles) megalodon’s size Different analysis = Different size estimates All studies conclude Meg was huge! Most scientists feel Megalodon was between 45-60 feet long The Circle of Life A shark’s skeleton is composed of cartilage, which does not preserve in the fossil record However, shark vertebrae do calcify Growth rings are preserved in shark vertebrae Shark vertebrae are discs which are called centra Growth rings are recorded in these centra Number of rings indicates the shark’s age at death Shark centrum Tree rings Centrum with growth rings What did Megalodon Eat? Megalodon was the top predator of its time It would need to eat a lot to survive An adult female probably weighed over 100 tons Megalodon most likely ate whales, large fish, seals, sea turtles, and whatever else it wanted! Estimates show Megalodon would average 2,500 lbs of food per day! When Was Megalodon Alive? Megalodon lived from about 20 to 2 million years ago Fossil teeth and (rarely) centra are found in ancient marine sediments Megalodon is extinct! Meg evolved to eat giant whales that appeared as the oceans cooled in the Miocene and Pliocene Where Did Megalodon Live? Megalodon had a worldwide distribution Cosmopolitan species Adults lived offshore (pelagic) Most likely had “nurseries” closer to shore The Ea