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#501 21 August 2017 12:12:23

Любитель животных
Откуда: Восточный Аллигатор-Ривер
Зарегистрирован: 28 November 2014
Сообщений: 259

Re: Мегалодон

Almost all reconstructions of Megalodon are based on the overriding assumption that it was very like the modern White Shark, only more so. But what about the substantial cadre of paleontologists - including Mikael Siverson and David Ward - who believe that the similarities between the teeth of Megalodon and the modern White Shark are superficialities borne of convergence and that the latter definitely is not closely related to or derived from the former? According to these scholars, Megalodon is derived from Otodus and should be placed in the genus Carcharocles. Paleontologist Shelton P. Applegate (who, incidentally, is of the school that regards Megalodon as a member of the genus Carcharodon) has stated that the teeth of Otodus more closely resemble those of a stout-toothed Sandtiger Shark (Carcharias) than they do those of the modern White Shark. If Megalodon descended from Otodus - a creature with Sandtiger-like teeth - rather than resembling a scaled up White Shark, could its body form have been Sandtiger-like, too?
Among extant lamnoids, the Sandtiger-like form has evolved in at least four distinct lineages (Mitsukurina, Carcharias, Odontaspis, and Pseudocarcharias) and may be symplesiomorphous (ancestral) for this group. In contrast, the classic 'lamnid body form' — featuring a narrow caudal peduncle supported by stout, lateral keels, tiny second dorsal and anal fins, and a lunate caudal fin — seems to be highly specialized and, as far as we know, appears to have evolved only once (if one regards the Cetorhinus + Lamnidae clade as monophyletic, which is strongly supported by morphological and molecular genetic data). Thus, if the Cretolamna-Otodus-Carcharocles scenario is correct, Megalodon may well have resembled a heavy-toothed, stocky Sandtiger.

http://www.elasmo-research.org/educatio … dtiger.htm

Такой внешний облик мегалодона все таки кажется более логичным, нежели откровенно устаревший "увеличенный вариант белой акулы":

Отредактировано Saltie (21 August 2017 12:12:54)



#502 12 October 2017 18:54:38

Зарегистрирован: 05 April 2016
Сообщений: 192

Re: Мегалодон

Kowinsky J. The Size of Megalodons. How large was the megalodon that your fossil tooth came from?. www.fossilguy.com. Проверено 14 марта 2016. Архивировано 18 января 2017 года.



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