March 13, 2009 -- A well-preserved fossil of a four- to five-million-year-old great white shark species, complete with 222 sharp teeth, suggests the ocean giants were once even bigger, and that they evolved from the fish-eating relatives of today's mako sharks. The fossil, excavated at the now-arid Pisco Formation region of Peru, could resolve an ongoing debate among shark experts: Did the great white evolve from so-called "megatooth", or Megalodon, sharks, the largest sharks to ever inhabit the planet, or are they more closely related to modern mako sharks? It is now clear that the ancient great white species shared habitat with the world's biggest megatooth, Carcharocles megalodon, a 60-foot monster whose jaw may have gaped wider than nine feet. Its megamouth could have been used to investigate, and perhaps swallow, the ancient whales, sea turtles, seals, penguins and even aquatic sloths that shared this part of Peru when it supported a shallow marine environment. Based on the great white relative's remains, however, the ancient species has been reconstructed "to look very similar to a modern white shark, but also retaining some features of the mako," lead author Dana Ehret told Discovery News. Related Content:
C. megalodon, in contrast to modern great whites, had ultra-thick teeth with "chevron," or V-shaped, features. Ehret, a Florida Museum of Natural History researcher, and his colleagues further determined that the prehistoric shark was 20 years old when it died. Like counting growth rings on a tree, the scientists counted light and dark bands in the shark's vertebrae, which calcify with age. While this particular shark was "only" about 17 feet long -- the same length as a respectably sized modern great white -- it appears that its close relatives were much bigger. Get More NewsSpiders, Scorpions Among World's Oldest CreaturesMany creepy crawlies have been on Earth much longer than previously believed.Blood-Sucking Vampire Bats Sing DuetsWhite-winged vampire bats "harmonize" with separated roost mates.Oldest Hebrew Writing Possibly FoundAncient inscriptions on a 3,000-year-old pottery shard could make history.Rare, Prehistoric-Age Reptile Found in N.Z.A tuatara has been spotted on the New Zealand mainland for the first time in 200 years.Iceman Has No Living RelativesOetzi, the 5,300 year-old frozen mummy, left no living genetic legacy.SLIDE SHOW: Landscapes of TerrorWhat makes a place feel scary? There are scientific explanations.It's Official: People Are Warming the PolesHumans are conclusively to blame for polar warming, say scientists.Eight-Armed Animal Preceded DinosaursWhat may be one of Earth's first animals was no bigger than a coaster and had eight arms.Phoenicians Live on in People's GenesOne in 17 Mediterranean men may be descended from ancient Phoenicians.Pesticides, Fertilizers Linked to Frog DeclineA pesticide is found to promote parasites among amphibians.Hubble Telescope Taking Photos AgainThe Hubble Space Telescope is once again snapping stunning photos of the universe.Andean Mummy Hairs Show Hallucinogen UseScientists find direct evidence of hallucinogenic drug use among ancient Andeans.Opals on Mars Reveal Planet's Long Wet PastOpals found on Mars suggest the planet has been wet for much longer. |
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