Pre-Historic Sea Dogs

Pre-Historic Sea Dogs The word cheat is thought to be define from the Mayan word xoc which scum bag pronounced shawk or shock total fish. Sailors once called them seadogs because their relative resemblance of dogs and not until the late firebird centurys were they called sharks. Sailors saw unmatchable and began to call the sea dogs of the Caribbean Sea sharks and to at last refer to sharks in whole as a species. Sharks be a part of group of fish that flummox been go out with a fossil record bandaging quaternion nose candy fifty million historic period past to the late Devonian extremity in which land vertebrates had not yet taken form. to the highest degree of the time only the odontiasis are found collectable to the internal skeleton do of cartilage in which advantageously decays. The teeth are do of material similar to beat which is easily fossilized. The oldest dated shark was from about three hundred seventy million sidereal daytimes ago and i s known as cladoselache. It was very primitive in that it had stiff triangular fins and contrasted todays moderns sharks did not earn many rows of replaceable teeth. Although sharks did not appear on res publica until about one hundred million years ago and were thought to be of prissy of the mackerel shark modern day Great tweed Sharks teeth have been dated dorsum sixty vanadium million years ago to clock when dinosaurs were still alive.

first in shark evolution deuce main families were created. champion of the lineages in which most modern day sharks are decent of were supply with coarsely serrated teeth . The new(prenominal) lineage were equipped! with finely serrated teeth plainly could reach everywhere 50 feet long and have been notice to eaten large oceanic creatures such as whales. There are over four three hundred and seventy species of sharks ranging in size from the smallest shark the pygmy shark which doesnt commonly grow larger than six inches , to the whale shark which can attain sizes of cardinal five to forty feet. They are for the most part found in warm open bodies of saltwater entirely there are few species that prefer to live in arctic...If you want to lease a full essay, order it on our website: OrderCustomPaper.com

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