User:Alekshandr

Carcharodon megalodon Temporal range: Late Oligocene-Early Pleistocene
Megaladon Prehistoric Shark
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Subphylum:	Vertebrata
Class:	Chondrichthyes
Subclass:	Elasmobranchii
Order:	Lamniformes
Family:	Disputed; Lamnidae or Otodontidae
Genus:	Disputed; Carcharodon or Carcharocles
Species:	†C. megalodon
Binomial name
Disputed; Carcharodon megalodon or Carcharocles megalodon For Carcharodon megalodon, Agassiz, 1843
Synonyms
Procarcharodon megalodon Casier, 1960 Megaselachus megalodon Glikman, 1964

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

Megalodon was the largest predator, terrestrial or aquatic, that existed on Earth. Although there is no consensus on the size, it is thought that mediates between 15 and 30 meters. Teeth could reach 18 cm. Fed on whales and lived for twenty million years (Eocene and Pliocene), until about 2-3 million years.

The uncertainty as to its size is due to the lack of fossil records (besides teeth) by its skeleton is cartilage rather than bone (sharks are condróstomos), which makes it harder to fossilization. Sometimes appear vertebrae, but are very rare. Even the larger teeth are already a precious find, because in 15 million years, Nature has time to do a lot of "damage". The teeth in a better state of preservation make known the evolutionary history of sharks. The Megalodon has serrated teeth while their predecessors such as C. auriculata still had several cusps and large lateral dimensions (which are already lower in C. angustidens - the closest relative of C. megalodon).

Even though they may have an idea of the extent of the Megalodon, he was at least 2-3 times higher than the white shark. The open mouth would be about 2 meters wide and 2.7 meters tall.

The feeding of this giant come across the fossils of whales that have the teeth marks of the shark. To ensure the daily consumption of food (about 2% of its body weight) the Megalodon hunt prey with half of its size or larger. We can therefore rest easy. Even if it is true, as some say, that this animal still lives in the depths of the oceans, man is not part of the diet. We are too small.

Discovery

Researchers at the University of Florida (USA) confirmed in the latest issue of the Journal of Vertebrate Paleontology that the current white sharks (Carcharodon carcharias) evolved mako shark teeth broad and not megalodon (Carcharodon megalodon), the largest carnivorous fish that met , as some paleontologists thought. The results are based on the fossil of a primitive species of white shark of between 4 and 5 million years old.

Find fossils of sharks is unusual because the sharks have most of its skeleton composed of cartilage. The new specimen, however, have been preserved much of spine, 45 vertebrae, a head and a mouth with teeth 222.

The finding could end an old debate on the evolutionary tree of these animals. For over 150 years paleontologists debated whether the white shark (Carcharodon carcharias) is a smaller relative of the line of species belonging to the enormous Carcharodon megalodon, or proceeding out of the mako tooth wide.

According to the group that defended the line of the mako shark, should have changed the name of the genus of megalodon, which measured up to 18 meters long, to differentiate between the ancestors. Research published in the Journal of Vertebrate Paleontology confirms that the megalodon and modern white sharks are much less related than some paleontologists thought.

Like most sharks, Megalodon's teeth were probably located in rows which rotated into use as they were needed. Most sharks have about 3-5 rows of teeth at any time. The front set does most of the work. The first two rows are used for obtaining prey, the other rows rotate into place as they are needed. As teeth are lost, broken, or worn down, they are replaced by new teeth. Megalodon may have had hundreds of teeth at one time. It did not chew their food like we do, but gulped it down whole in very large chunks.

MEGALODON'S DIET

Megalodon's diet probably consisted mostly of whales. Sharks eat about 2 percent of their body weight each day; this a bit less than a human being eats. Since most sharks are cold-blooded, they don't have to eat as much as we eat (a lot of our food intake is used to keep our bodies warm).

Habitats

Megalodon is supposed to have lived in an deep sea habitat. 

Only during the last century scientists have started to learn about this habitat and discovered for example that an animal its extinction was meant to be dated some million years ago Both species are inhabitants of the deep sea, a habitat still full of secrets waiting to be revealed. Both were supposed to live in the same epoch of earth's history and meant to be extincted. There is yet no reason identified which would sufficiently explain why megalodon would have been extincted. But there are reports from fishermen etc. about seeing mega sharks on the open sea, extending the size of the recent white shark by far. Plus, there are findings of megalodon teeth with an estimated age (radioactive isotope probing) of only round about 5.000 years.

So probably the megalodon is still among us.