Class: Chondroichthyes
Order: Lamniformes
Family: Otodontidae
Genus: Otodus
Species:  obliquus

The shark Otodus obliquus lived between the late Paleocene and the Eocene, between 40 and 60 million years ago.
As all the sharks its skeleton was made of cartilage and this is the motive for which only teeth and some fossilized vertebrae arrived to us.
The Otodus obliquus was a great raider whose dimensions arrived to around 9-10 m of length and 15 tons of weight.
Fossil rests have been found (teeth and vertebrae) from excavations effected in Africa, Europe, Asia and North America, situation that makes to suppose that this shark was largely diffused in the oceans of 60 million years ago..
Considered the dimensions and the characteristics it is hypothesized that the Otodus obliquus fed him of sea mammals, great fishes bony and other sharks.
Currently the almost totalities of the teeth of this enormous shark originate from the mines of phosphate of Morocco and it is not rare therefore to find on the markets blocks of this substance with set numerous teeth or parts of them.
The teeth of the Otodus obliquus have triangular form, they are wide (up to 8-10 cm) with smooth and sharp edges and are present one or more side cuspids.
 

The paleontologists have considered that this shark can be the progenitor of the Carcharodon / cles megalodon, the megalodon shark, that reached the length of 14 m and 30 tons of weight.  An important element for this consideration has been the recovery of some fossil teeth, (considered "transition" teeth) very similar to those of the kind Otodus, that introduces a light serration in the edges, characteristic that supports the theory that the kind Otodus is evolved up to the kind Carcharodon / cles, arriving therefore to the megalodon shark.

Considering the theories on the evolution of the megalodon shark and of the actual white shark the evolutionary lines could be been the followings:
1) the first evolutionary line sees the Otodus obliquus progenitor of the megalodon shark Carcharodon megalodon, which is evolved thin to reach the actual white shark Carcharodon carcharias.
2) the second evolutionary line considers the Otodus obliquus evolved to reach the Carcharocles megalodon, which is always the megalodon shark but inserted in the different kind Carcharocles.
In base to this second theory the actual white shark Carcharodon carcharias would have had a parallel evolution, different from that of the megalodon shark
 

The teeth of the Otodus obliquus have triangular form, they are wide (up to 8-10 cm) with smooth and sharp edges and are present one or more side cuspids.

Tooth of Otodus obliquus with two side cusps

Tooth of Otodus obliquus

Tooth of Otodus obliquus

Marco Angelozzi - www.prionace.it

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