The Great White Shark (Carcharodon carcharias) has a reputation of being both the biggest and most aggressive shark in our seas. And it is pretty damn big – the largest to be measured was 6.4m but apparently they could grow as big as 8m. Teeth marks on whale carcasses provide evidence of these giant fish, and reveal there are Great Whites out there twice the length of my car…
Alarming as this is, the Great White shark is not the largest to have lived.
If you were swimming in the ocean 1.6 million years ago, you’d have had much bigger fish to fry. Possibly a 30m long fish known as Megalodon. Translating to big tooth, Megalodon (Carcharodon megalodon) is the largest shark to have existed, a shark that makes other predators like the T-Rex seem small.
Sharks are structurally supported by cartilage, not bones, and this rarely fossilises, so no skeleton of Megalodon has ever been found. What has been discover however, are their teeth. The length of these teeth can be more than 120mm long and from studying these, scientists have estimated Megalodon could have reached up to 30m. We’re now looking at something more than 7 times the length of my car. Something approximately the same size as the Blue Whale! And when you compare these teeth, something surprisingly bigger than our Great White.
Many believe that Megalodon was the predecessor of the current Great White due to similar serration on their teeth, but research has revealed it is more likely Great Whites evolved from extinct Mako Sharks. So what happened to Megalodon, and why?
Well no one really knows. Naturally there are people who believe it’s still out there, turning to historical photographs, severed whale carcasses and upturned boats as proof, but I’m not convinced. Whatever the answer, Megalodon is one mighty animal and its sheer size is terrifying, impressive – and just that little bit odd.
Keyes, I. (1972) New records of the Elasmobranch C. Megalodon (Agassiz) and a review of the genus Carcharodon in the New Zealand fossil record, New Zealand Journal of Geology and Geophysics, 15(2), 228-242, DOI:10.1080/00288306.1972.10421956
Randall, J. (1973) Size of the Great White Shark (Carcharodon). Science, 181(4095), 169-170. Retrieved from: http://www.jstor.org.ezproxy.library.uwa.edu.au/stable/1736867
Nyberg, K., Ciampaglio, C., & Wray, G. (2006) Tracing the ancestry of the Great White shark, Carcharodon carcharias , using morphometric analyses of fossil teeth. Journal of Vertebrate Paleontology, 26(4), 806–814. Retrieved from: http://sharkmans-world.eu/research/Ancestry%20of%20Great%20White%20Shark.pdf