Evolution of the shark

                    

                            sharks date back  450-420 million years before land and plants all shark came from the type of shark called megalodon and the shark megalodon was 67 feet long and still lives to this day and eats whales and other sharks . sharks grow 10 to 1000 teeth over a life time modern sharks look and think more different thain the sharks of the past.

cladoselache shark only found in the devonian period 370 million yaers ago a fast swimmers and at a size of 6 feet long 

teeth of the cladoselache shark 

 Helicoprion shark

 (Dmitri Bogdanov)

                                                   

                                                              crested horn shark





this shark has two dorsal fins they are both spines they are bottom duelers and and are nocturnal and eat off the reefs and all of the small organisms they prefer rocky vegetated areas they swim down (305)ft or (90)meters down and they can not harm humans and you can see the two horns on the head that gave them there name and they hide there eggs in sea weed and the crested horn baby is 22 cm long 

     in my idea of the sharks life style the shark would be a good pet