October 6, 2010 : Megalodon (Extinct)

Megalodon

The megalodon, Carcharodon or Carcharocles megalodon (pronounced /ˈmɛɡələdɒn/MEG-ə-lə-don, "big tooth" in Greek, from μέγας and ὀδούς) is an extinct megatoothed shark that existed in prehistoric times, from the Oligocene to Pleistocene epochs, approximately 25 to 1.5 million years ago.

C. megalodon may have been the largest and most powerful macro-predatory fish that ever lived. Fossil remains of C. megalodon indicate that it possibly approached a maximum of around 20.3 metres (67 ft) in length. C. megalodon has been assigned to the order Lamniformes but its phylogeny is disputed. Scientists suggest that C. megalodon looked like a stockier version of the great white shark, Carcharodon carcharias, in life. Fossil evidence confirms that C. megalodon had a cosmopolitan distribution. C. megalodon was a super-predator, and bite marks on fossil bones of its victims indicate that it preyed upon large marine animals.

According to Renaissance accounts, huge, triangular fossil teeth often found embedded in rocky formations were once believed to be petrified tongues, or glossopetrae, of the dragons and snakes. This interpretation was corrected in 1667 by a Danish naturalist, Nicolaus Steno, who recognized them as ancient shark teeth (and famously produced a depiction of a shark's head bearing such teeth). He mentioned his findings in a book, The Head of a Shark Dissected, which also contained an illustration of a C. megalodon tooth, previously considered to be a tongue stone.

A Swiss naturalist, Louis Agassiz, gave this shark its scientific name, Carcharodon megalodon, in 1835, in his research work Recherches sur les poissons fossiles (Research on fossil fish), which he completed in 1843. The teeth of the C. megalodon are morphologically similar to the teeth of the great white shark. On the basis of this observation, Agassiz assigned the genus Carcharodon to the megalodon. While the scientific name is C. megalodon, it is often informally dubbed the megatooth shark or giant white shark or even monster shark.