A critical evaluation of the supposed contemporary existence of carcharodon megalodon

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A Critical Evaluation of the Supposed Contemporary
Existence of Carcharodon megalodon

Roesch, Ben S. 1998. A Critical Evaluation of the Supposed Contemporary Existence
of Carcharodon megalodon. TheCryptozoology Review 3 (2): 14-24.

Many consider the white shark (Carcharodon carcharias) to be among the most incredible creatures to roam the oceans today. Growing to lengths upwards of 6 m (20 ft) and weights of more than 2 000 kg (4 400 lb), this large lamnid shark is responsible for occasional attacks on humans. It has become the quintessential shark to many, especially after the success of themovie Jaws, which made the white shark’s name and toothy visage infamous.

About 16 million years ago during the Miocene (1), however, an even larger shark, possibly similar to the C. carcharias, appeared in the world’s oceans. Carcharodon (or Carcharocles) megalodon may have attained an astonishing maximum length of 15 m (50 ft), and weighed as much as 50 tonnes (49 tons) (Gottfried et al.1996). Such estimates are gleaned from teeth and very rare skeletal components of the animal (sharks have a cartilaginous skeleton that does not readily fossilize; most species of fossil sharks are known from their teeth only, which are very durable structures). Traditional research holds that C. megalodon was ancestral to the white shark, but recent research suggests that it was actually a closerelative (2). Authors such as Gottfried et al. (1996) envision C. megalodon as a much larger and bulkier version of this white shark. With a mouth large enough to swallow a cow whole and broad, triangular teeth much like those of the white shark (but up to 17 cm [7 inches] high, as opposed to a maximum of 6 cm [2 inches] in white sharks [Fig. 1]), C. megalodon apparently fed on primitive whales andother large marine mammals (Fig. 2) (3). It is possible that C. megalodon hunted in the same stealthy manner that white sharks often employ to prey on pinnipeds---stalking prey from below and then rising up at a high speed to deliver a massive, often fatal first bite (4). About 1.5 million years ago at the end of the Pliocene, C. megalodon disappeared, due to a variety of possible reasons(Applegate and Espinosa-Arrubarrena 1996), some of which will be discussed below.

Despite the general consensus among zoologists and paleontologists that C. megalodon is extinct, it has been suggested by several cryptozoologists and other researchers (e.g. Stead 1963; Clark 1968; Clostermann 1969; Perry 1972; Cartmell 1978; Goss 1987; Bright 1989; Corliss 1991; Shuker 1991, 1995, 1997) that thisenormous shark may continue to exist in the deep-sea or another remote part of the ocean. These proponents of C. megalodon survival cite a small body of ‘evidence’ to support their claim, including eyewitness accounts, unfossilized and recently fossilized C. megalodon teeth, and the discovery of the megamouth shark (Megachasma pelagios) in 1976. (Other researchers, such as Ellis [1975, 1994], Ellis andMcCosker [1991], and, to a lesser extent, Steel [1985], provide a level-headed, yet open-minded, review of the question of C. megalodon survival). It will be argued below, however, that all of this proposed evidence is weak, and that the suggestion of present-day survival of C. megalodon does not conform with accepted paleontological and ecological knowledge.Eyewitness Accounts
A few reports of alleged encounters with large, unidentified sharks have been proposed as evidence for C. megalodon survival. One of the most widely cited is an extraordinary tale recounted by Australian naturalist David Stead (1963: 45-46):

In the year 1918 I recorded the sensation that had been...