The Megalodon (Carcharodon megalodon) which literally means"great tooth" in ancient greek, was a prehistoric shark that lived between 5 to 1.6 million years ago, thought some contest that this huge preditor never went extinct at all. Like modern sharks the Megalodon’s skeleton was mostly cartilage and not bone, this resulted in a fossil record which consists mainly of teeth and a small number of fossilzed vertebra. Megalodon’s teeth, which are very similar to that of the Great White Shark, can measure up to 7 ½ inches long. Originaly scientists belived that the Megalodon was a close reletive to the Great White Shark, however a growing number of scientists now dispute this close realationship, instead citing convergent evolution as the reason for the dental similarity. Regardless, it is extrapolations from the tooth size of Megalodon compared to that of the modern Great White Shark that provides us with our conceptions about what this ancient shark was like.
Estimates of the Megalodon’s size ranges from 30 to 50 feet, the largest of the speices are thought to have reashed nearly 100 feet in length. The wieght of the larger sharks is believed to reash almost 65 tons with the average length sharks reaching between 25 and 35 tons. It is gereally excepted that the diet of the Megalodon cosisted almost entirely of whale meat, and assumming similar metabolic weight ratios as the Great White Shark, it is estimated that a large Megalodon would need to eat nearly one fifteenth its wieght in food daily.
One thoery suggests that becouse Megalodon fed largley on whales they went extinct as the polor seas became to cold, allowing whales to swim out of reach of sharks during the summer months. Other explinations are simpler, suggesting that any prolonged disturbance of the foodchain would wipe out a predator with such massive metabolic requirements. Some researchers believe that Megalodon may have faced compitition from the Killer Whale which evolved less than five million years ago. With their pack behavior and high intellegence the Orca could have crowded the shark out of a declining food source. Once food was scares the sharks massive size was no longer and advantage and infact lead to faster starvation. Killer Whales may have even gone as far as to feed upon juvinelle Megalodon’s seeing them more as a food source than a threat. Once Megalodon populations went below a certain level, they could no longer find other Megalodons of the opposite sex. Thus fewer sharks were born than died, and extinction set in.
The Physical Evidence
Perhaps the best, and only evidence we have that the Megalodon may still exist today, are two teeth. Brought up by the HMS Challenger in 1975 during a deep sea dredging exploration, these teeth date back as recently as 10,000 to 15,000 years ago. These teeth were dated by estimating the amount of time it took for manganese to accumulate on them, although it is quite possible the teeth were fossilized before being encrusted. Most experts believe that the Megalodon was a coastal shark, which is where the majority of teeth have been discovered. These teeth suggest that as little as 10,000 years ago, a far cry from being extinct for 5 million years, the Megalodon may have still existed, perhaps evolving to survive in the depths of the ocean to escape extinction. It is a well known fact that the oceans of the world are vastly un explored and creatures like the Giant Squid, which only existed in legend, and the Celocanth (which was thought to have gon extinct millions of years ago, can exist with out detectiction.
One of the mostfamed examples of a possible Megalodon sighitng was retold by Australian naturalist David Stead. Though widely circulated, this account is generally regarded as of little value, because most of the claimants are anonymous:
"In the year 1918 I recorded the sensation that had been caused among the "outside" crayfish men at Port Stephens, when, for several days, they refused to go to sea to their regular fishing grounds in the vicinity of Broughton Island. The men had been at work on the fishing grounds—which lie in deep water—when an immense shark of almost unbelievable proportions put in an appearance, lifting pot after pot containing many crayfishes, and taking, as the men said, "pots, mooring lines and all". These crayfish pots, it should be mentioned, were about 3 feet 6 inches [1.06 m] in diameter and frequently contained from two to three dozen good-sized crayfish each weighing several pounds. The men were all unanimous that this shark was something the like of which they had never dreamed of. In company with the local Fisheries Inspector I questioned many of the men very closely and they all agreed as to the gigantic stature of the beast. But the lengths they gave were, on the whole, absurd. I mention them, however, as an indication of the state of mind which this unusual giant had thrown them into. And bear in mind that these were men who were used to the sea and all sorts of weather, and all sorts of sharks as well. One of the crew said the shark was "three hundred feet [90 m] long at least"! Others said it was as long as the wharf on which we stood – about 115 feet [35 m]! They affirmed that the water "boiled" over a large space when the fish swam past. They were all familiar with whales, which they had often seen passing at sea, but this was a vast shark. They had seen its terrible head which was "at least as long as the roof on the wharf shed at Nelson Bay." Impossible, of course! But these were prosaic and rather stolid men, not given to 'fish stories' nor even to talking about their catches. Further, they knew that the person they were talking to (myself) had heard all the fish stories years before! One of the things that impressed me was that they all agreed as to the ghostly whitish colour of the vast fish. The local Fisheries Inspector of the time, Mr Paton, agreed with me that it must have been something really gigantic to put these experienced men into such a state of fear and panic."
In the 1960’s along the outer edge of Australia’s Great Barrier Reef, an 85 foot [26 m] ship experienced engine trouble which forced it to weigh anchor for repairs. Although the men subsequently refused to openly report what they had seen for fear of public ridicule, the captain and his crew later told friends of sighting an immense shark as it moved slowly past their ship. Whitish in color, they were awed by its size. It was as long if not longer than their boat! Experienced men of the sea, they too were certain the creature was not a whale.
The Stats – (Where applicable)
• Classification: Shark
• Size: 40 to 50 feet, with the largest reaching nearly 100 feet
• Weight: 25 to 35 tons with the largest weighting in at nearly 65 tons
• Diet: Meat, mainly whales
• Location: Warmer Oceans of the World
• Movement: Swimming
• Environment: Warm Costal Waters