Tales from the Cryptozoologicon: Megalodon!
The other day I presented works of art and texts from the next Cryptozoology, a book currently being written by John Conway, CM Kosemen and myself and due out later this year. Today I want to do the same.
This time we will focus on the section on Megalodon, the Megatooth shark. My God, how timely! (Read on to see why). Sharks aren’t tetrapods (and therefore generally outside of Tet Zoo’s remit) but, damn it, I’ve broken the rules before, I’ll break them again here.
The seas are full of monsters. Or, they are according to some of the cryptozoological literature, anyway. As if numerous yet unknown giant marine mammals and reptiles and absurdly oversized cephalopods weren’t enough, cryptozoologists have also advocated the possibility that Megalodon of Carcharocles – popularly nicknamed Megalodon or the Megatooth Shark – is not only known from the fossil record, but may also survive to the present day. Megatooth sharks are, unsurprisingly, almost entirely known for their enormous teeth, the largest specimens of which are 16.8cm long. The vertebral centers of Megatooth sharks are known in addition to the teeth, but that’s it, and – unsurprisingly – there’s been a lot of tendency to overestimate the size of this giant. A total conservative length about 15.9 m was extrapolated by Gottfried et al. (1996) but they also calculated total lengths of up to 20 m for some individuals. These authors also suggested that C. megalodon had a deeper, more blocking skull than the great white shark Carcharodon carcharias.
While C. megalodon is often imagined as a giant version of the modern Great White, it can only be remotely related to it. In fact, some experts assign these sharks to entirely different sections of the shark family tree and at least three different technical names are used for C. megalodon (Carcharocles megalodon, Carcharodon megalodon and Megaselachus megalodon). Either way, good evidence shows that Megalodon was ecologically similar to the Great White, although much larger and more powerful.
Bite marks preserved on the bones show that Megatooth sharks regularly fed on dolphins and baleen whales, although it remains unknown whether the bite marks we know of represent scavenging or hunting live cetaceans. Megatooth shark teeth are frequently found in areas where baleen whale remains are common (Purdy 1996), and the two shared the same habitat.
According to the fossil record, C. megalodon went extinct for some time during the early Pleistocene, probably because cooling conditions reduced its preferred habitat [UPDATE: be sure to read comment # 6 below. A Pleistocene extinction date may be too recent!]. And here we come to the cryptozoological case of Megalodon survival: the kind of thing discussed in various popular books and magazine articles about mysterious creatures (Shuker 1991, 1995, 1997). The presumed survival of Megalodon was reviewed by Roesch (1998) who essentially concluded that there was no reason to take the presumed survival of Megalodon seriously. We agree with his conclusions.
A very small number of alleged eyewitness stories and encounters essentially form the heart of the record of Megalodon’s survival. In the best known and most often repeated, Australian naturalist David Stead described a tale told to him in 1918 by Australian crayfish fishermen in which a gargantuan, ghostly white shark, perhaps 90m in length, emerged from the depths to take their crayfish traps. , mooring lines and everything attached. This story has sometimes been taken half-seriously, partly because Stead (a well-known and respected writer and researcher, very experienced in ichthyology) explained the reliable nature of his (anonymous) sources. Alas, a fisherman’s story of a monster white shark eating crayfish traps is hardly a reliable source and the account is an amusing anecdote that we cannot take as evidence of any kind.
Two other allegedly possible giant shark sightings Megalodon sightings are clearly misdescriptions of whale sharks type of rhinoceros. There is also a story from the 1960s (recounted in a popular 1978 book) about a giant white shark, over 80m tall, told by the anonymous crew of a ship. So we are left stories: scary stories of the kind that sailors like to tell others when they return to shore. Indeed, the case for Megalodon’s survival is so weak that it’s not really “a case”.
The survival of megalodon is also thought to be supported by the discovery of teeth that are not fossilized or that are thought to be covered in such a thin layer of manganese dioxide that they must surely be young, in geological terms. Indeed, the teeth (the most famous of which were unearthed by the Challenger expedition of the 1870s) have been misinterpreted and there is no reason to think that they are geologically young, let alone modern (Roesch 1998).
The speculative part
Now what about our speculative parallel universe, where all cryptids are real and megatooth sharks still swim the oceans? Again, it would be hard to say anything speculative about Megalodon that hasn’t already been said. For a giant, macro-predatory, whale-eating shark to remain elusive and undocumented by biologists, it would have to be absurdly secretive, spending nearly all of its time off the surface, away from ships, and away from coastal regions. where he would surely be discovered. It must therefore be a deep-sea animal that specializes in prey that it can reliably encounter at depth, and it must have moved to this prey base some time since the Pliocene or early Pleistocene. [The brilliant image below shows a modern-day Megalodon, by John Conway. For the full-size version go here.]
This evolutionary change occurred at breakneck speed: as a new, slower growth regime and the occupation of an otherwise untapped ecological niche encouraged Megalodon to grow significantly larger than the approximately 20 m attained by its ancestors. , it has not yet gone completely abyssal like other deep-sea sharks and still visits the surface to eat crayfish traps and small fishing boats on occasion. We should imagine the new Abyssal Megalodon – presumably different enough to warrant classification as a new species Modern Carcharocles – to haunt underwater canyons and places where whales and elephant seals, etc., are regular visitors.
Previously it was Sirens. Discovery wins again… (read: loses)
Of course, our coverage here of Megalodon is extremely timely since Discovery just screened a notorious pseudo-documentary in which they apparently try to trick naïve viewers into believing that Megalodon still exists, and that there is evidence of that possibility. in the manner of assorted photos and other evidence [disclaimer: at the time of writing, I haven’t seen said TV show]. The idea that a once reputable documentary TV channel could air such a show is incredible, even in the wake of the two ridiculous siren shows aired by the same channel in the past few years.
So far, I’ve only heard displeasure and anger towards Discovery, with some people even demanding an apology. Remember that their Megalodon show is not presented as mere entertainment at the Sharknado, but as a documentary screened alongside real documentaries about real sharks, their biology, their world and their fate. It will surely be interpreted as real by a large percentage of its viewers. As this screenshot of Discovery’s facebook page shows (above), people aren’t happy (at least the people who leave comments on the page… the worrying number of “likes shows how popular this garbage is). If some of this energy can be converted to help benefit real sharks in the real world, we can be happy that something good has come out of it.
the Cryptozoology – by John Conway, CM Kosemen and Darren Naish – is due out later in 2013 and will be published by Irregular Books. Follow @IrregularBooks on Twitter.
Refs – –
Gottfried, MD, Compagno, LJV & Bowman, SC 1996. Skeletal size and anatomy of the giant “megatooth” shark Carcharodon megalodon. In Klimley, AP & Ainley, DG (eds) Great white sharks: the biology of Carcharodon carcharias. Academic Press (San Diego), p. 55-66.
Purdy, RW 1996. Paleoecology of fossil white sharks. In Klimley, AP & Ainley, DG (eds) Great white sharks: the biology of Carcharodon carcharias. Academic Press (San Diego), p. 67-78.
Roesch, BS 1998. A critical assessment of the supposed contemporary existence of Carcharodon megalodon. The Cryptozoology Journal 3 (2), 14-24.
Shuker, KPN 1991. The Search for Monster Sharks. Destiny 44 (3): 41-49.
– . 1995. In Search for prehistoric survivors. Blandford, London.
– . 1997. From flying toads to snakes with wings. Llewellyn Publications, St. Paul, Minnesota.