Fossilised Shark Tooth

04 October, 2009

Fossil Shark Tooth - Carcharodon megalodon.
Fossil Shark Tooth - Carcharodon megalodon.
Image: Rodney Start
Source: Museum Victoria

Question: Can you tell me about this giant tooth I found that looks like a shark tooth? Is it a fossil? It looks pretty new but is huge and I can’t imagine what shark it would have come from!

Answer: This huge tooth is indeed a fossil! It comes from an extinct shark called Carcharocles megalodon, which lived approximately 20 to 3 million years ago during the Miocene and Pliocene epochs. The word megalodon comes from Ancient Greek words meaning ‘big’ and ‘tooth’ and the shark is known by various names, including the Giant ‘Mega-tooth’ Shark, Giant-toothed Shark, the Giant White Shark and the Fossil Great White Shark.

Megalodon was distributed throughout the oceans of the world, with fossil remains found from Belgium to California; from Morocco to Peru. They are also found at a number of sites in Australia, including the Melbourne suburb of Beaumaris. Only the teeth, vertebrae and fin bones of the Megalodon have been found because shark skeletons are mainly made of cartilage, which decomposes too quickly for it to become fossilised.

Nevertheless, we still can find out lots of information about these ancient sharks from these fossil remains. We can compare them to modern sharks and infer information from similarities of their skeletal material, including their bone structure, development, hunting and eating habits.

The Megalodon probably looked similar to the modern Great White Shark (White Pointer) but was much bigger. Its fossils indicate that it could have measured up to 15m in length and weighed up to 50 tonnes (50,000kg). The teeth of this giant can be up to 18cm long. Reconstructions have been made of their jaws based on the shape of the teeth and suggest that the gape was up to 2m, enough for a human to stand up in its mouth! The size, shape and serrated edges of Megalodon teeth are similar to the Great White and it probably ate whales, seals, turtles and large fish. With its enormous size Megalodon would have needed a large amount of food, perhaps up to 1100kg of meat every day.

The Carcharocles megalodon used to be known as Carcharodon megalodon. Scientists had for many years thought the modern great white (Carcharadon carcharias) was an ancestor of the Megalodon and, therefore, were classed in same genus (Carcharodon). But recent work by palaeontologists has now turned this idea around, suggesting that the Megalodon and Great White are descended from different lines.

Why did these giants die out? The increasingly cold climate in the late Pliocene (which heralded the beginning of the great Ice Age in the Pleistocene) almost certainly was responsible for the extinction of these creatures. There are many factors that may have affected them but it is possible that they may not have been very well adapted to the cooling sea temperatures, or that their prey moves to waters too cold for them to follow to. Another more speculative idea is that Megalodon was out-competed by Killer Whales, which seem to have evolved towards the end of Megalodon’s reign.

Rumours still abound among fisherman about giant sharks bigger than normal Great Whites. This has led to stories that these creatures may still be living in the deep sea somewhere. But scientists have not found any Megalodon teeth in recent marine deposits and the rumours are without basis. Like many of the giant animals that roamed the earth in the era, these marine creatures of the Miocene and Pliocene can only be seen in paintings and re-creations.

Comments (11)

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julianne dynan 8 October, 2009 13:05
my comment is why is the carcharocles megalodon extinct and how did it die. from julianne!!!!!!!!!!
julianne dynan 8 October, 2009 13:12
wow! it is very intresting i liked it and the GIANT TOOTH it was so gaint!!!
julianne dynan 8 October, 2009 14:56
Discovery Centre 9 October, 2009 12:39

It's not really clear why the Carcarocles megalodon became extinct. We have listed some of the theories above in the second last paragraph. You can find more detailed information about possible reasons for extinction on the ReefQuest Centre and National Dinosaur Museum websites.

Taylor 22 December, 2010 00:31
Did megalodon gave birth to live young like the great whites of today?
noah ***** 17 November, 2012 18:05
it is very probable, and 99% yes. but it culd have not anyhthings possible in science. but from the distinct simmilarities of the two species and that almost all sharks give birth to live offspring suggests that they indeed did.
Mike berry 14 March, 2011 00:15
Are there any sites around Australia where I could search for megalodon teeth?
Discovery Centre 18 March, 2011 10:38
Hello Mike - There are several sites in Australia where these teeth are found, but many of them are located on private property, Crown land or sites that are too dangerous for public access. If you have a look at a copy of Vertebrate Palaeontology of Australasia, there is a table of possible sites, but please be aware that many of these sites are not suitable for general prospecting.
lakeisha 6 April, 2011 10:36
i found a smaller version is that from the same shark?
Discovery Centre 7 April, 2011 12:44
Hi Lakeisha. It's a bit hard to identify something like this without an image. Could you please send an image of your tooth to our Ask the Experts Identifications page, along with information as per the Identification guidelines and we'll see if we can help.
scott 18 March, 2013 13:58
hi im wondering about ome possiable sites to look for fossils on the mornington peninsula with my 5yo son, and also about volunteering at a proffesional dig site
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