The Megalodon or Megatooth shark (Carcharodon megalodon, from ancient Greek, mega + odon, lit. "big tooth") was a giant shark that lived between 5 million and 1.6 million years ago.

The Megalodon is known only from fossil teeth, which are in some ways similar to great white shark teeth; recent studies cited by Roesch suggest Megalodon was a "close relative" of the great white. Some estimates of this creature's size range up to 50 feet (about 16 metres). Previous much larger reconstructions of the shark's size (up to 100 feet) are generally considered inaccurate.

Some recent reports of large shark-like creatures--including a sighting by writer Zane Grey, who was an avid fisherman--have been interpreted as surviving Megalodons, but such reports are generally considered misidentification of whale sharks or other large creatures.

Megalodon teeth have been discovered that some argue date as recently as 10,000 to 15,000 years ago, perhaps making the species' extinction a recent event, and making it more conceivable that Megalodon might yet survive in the deep ocean.

Others have countered that such recent estimates are inaccurate, and "claims of post-Pliocene C. megalodon ... are erroneous" and based on outdated methodology. [1] Roesch and others also note that Megalodons were probably coastal sharks, and that deep-sea survival is extremely unlikely.

Around 1995 the species was proposed to be placed in the new genus Carcharocles. To date this has not been resolved.

A supposed surviving population of Megalodon sharks has been the subject of fictional novels, including several by Steve Alten.

External links

• Megalodon: Shark Glossary
• An impressive photograph of this shark's jaw
• More photos
• Carcharodon or Carcharocles?
• A Critical Evaluation of the Supposed Contemporary Existence of Carcharodon megalodon by Ben S. Roesch
• Does Carcharodon Megalodon Still Exist? by Richard J. Ravalli, Jr.