It was the biggest shark the world had ever seen; indeed, the biggest fish the world had ever seen. The term super-predator doesn't seem to do it justice. It snacked on large whales. It was the magalodon shark and it had a bite force of 41,000 pounds.
The megalodon is shrouded in myth and mystery. Because sharks consisted of mostly cartilage, the fossil evidence has been sketchy: teeth, a few vertabrae, and not much else. Evidence points to this monster arising in the Oligene Era, about 25,000,000 year ago -- it was much more common during the Pleistocene, about 20,000,000 years ago -- and it died out perhaps 2,000,000 to 1,500,000 years ago. A few say that megalodon may have lived to about 10,000 years ago. SyFi Channel movies and some works of fiction claim they still exist.
The name megalodon (large tooth) was given to the shark by Louis Agassiz in 1835. It was not until 1909 that a replica of the shark's dentition was made by Bashford Dean of New York's Museum of Natural History. Dean's research proved to be faulty, however, and most modern scientists feel megalodon was about 70% of the size he estimated. Michael D. Gottfreid, after years of study, created the first reconstruction of a megalodon skeleton in the mid 1980's. This careful reconstruction is now on exhibit at the Calvert Marine Museum in Solomons, Maryland. In recent years, the scientists at the Calvert Marine Museum painstakenly created another replica for display at a museum in Cape Town, South Africa. These are the only two full megalodon skeletons in existence.
So what does this skeleton look like? I can tell you this sucker is big. The skeleton is that of a juvenile meg, only 37.5 feet long. Fossilized megalodon teeth found along the Calvert Cliffs in Southern Maryland measure about 1.5 inches to 4 inches in length, indicating that the megalodons these teeth came from were usually some 12 to 30 feet long. (It's felt that the shallow waters of the then-Calvert Sea was most suitable to young megs.) The skull is huge; its teeth intimidating; its eye sockets are comically large, giving one a giant bug-eyed impression -- but there is nothing comical about this shark's predatory ways. The ribs are gigantic and seem to go in every direction. The skeleton is suspended in a large room, the megalodon seems to go on forever, dwarfing the large pterodactyl-like skeletons sharing the room. On the opposite side of the room, a fossilized jaw of a prehistoric crocodile is puny in comparison.
How big would an adult, mature meg be? Some estimates give a maximum length of 82 feet, although most expert feel a maximum length would more likely have been about 67 feet. After years of study, Gottfreid and his colleagues published a paper showing how to determine length by the size of the shark's teeth. A 7 inch megalodon tooth, for example, would indicate a shark of nearly 60 feet in length -- that's three times the size of the largest great white. A 67 foot long megalodon would weight about 228,000 ponds. The line from Jaws, "we're going to need a bigger boat", would be an understatement.
Despite the SyFi movies and Steve Alten's Meg novels, the megalodon is a creature of the past. When you watch Shark Attack 3: Megalodon or Mega Shark vs. Giant Octopus or whatever other cheesy movie they come up with, breathe easy. Also please note that megalodon is not 70,000,000+ years old (which would put it contemporary with some of the dinosaurs) despite what some of those movies (and Steve Alten's boooks) say. In fact, the author of one book on the subject sued the distributor of Shark Attack 3 because the movie added pages of false information to his book, showing the phony pages onscreen!