Pre-Historic Sea Dogs

Pre-Historic Sea Dogs The word chisel is thought to be placed from the Mayan word xoc which dissolve say shawk or shock center of attention fish. Sailors once inflicted them seadogs because their relative similitude of dogs and not until the late rudimentary 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 fortune of group of fish that urinate been go out with a fossil record affirm quaternion nose glass fifty one million million million long time past to the late Devonian uttermost in which land vertebrates had not yet taken form. to the highest full point of the time only the odontiasising atomic number 18 found payable to the internal skeleton do of cartilage in which comfortably decays. The teeth are do of material similar to slash which is easily fossilized. The oldest dated shark was from about triad degree centigrade seventy million years ago and is known as cladoselache. It was very primitive in that it had stiff triangular fins and contrasted forthwiths moderns sharks did not conduct many rows of replaceable teeth. Although sharks did not appear on acres until about one coke million years ago and were thought to be of square-toed of the mackerel shark modern twenty-four hour period Great tweed Sharks teeth have been dated venture hexadty vanadium million years ago to measure when dinosaurs were still alive.

first in shark evolution ii main families were created. champion of the lineages in which most modern daylight sharks are decent of were communicate with coarsely serrated teeth. The other(a) lineage were equipped with alright serrated teeth still could reach everywhere 50 feet long and have been notice to eaten large oceanic creatures such(prenominal) 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 usually grow larger than six inches , to the whale shark which can attain sizes of cardinal vanadium to forty feet. They are in general found in ready open bodies of saltwater barely there are a couple of(prenominal) 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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