Giant carcharhinid shark?

Adam Khor

Hey everyone! Was wondering if any of you guys knows anything about giant prehistoric carcharhinids (requiem sharks)?
Megalodon and all those huge lamniforms are cool but, I can´t help but to think that there must have been a giant requiem shark at some point (my reasons to believe that are that one, it would be awesome, and two, many marine animals got to huge sizes during Miocene and Pliocene, so why not some member of the largest shark family?
So, basically, my question is, has any of you heard or read anything about such creatures (their teeth, at least) being found as fossils? I don´t know much about shark fossils so I may be missing something big!

Thanks!

Adam Khor

Wow, no one knows anythin' :cool:

Rubecula

Do we know for certain that Megalodon was NOT related to Requiem sharks? We only suppose it was related to Great Whites after all. Shark fossils seem to be limited to teeth.

Kess73

It would be very very difficult to prove that any prehistoric shark was a true requiem sharks.


People can make guesses based on what they know of modern requiem sharks, but there is nothing to show that there were sharks that gave birth to live fully formed young back then.



The biggest requiem shark nowadays is the Tiger shark, and the next biggest would have you looking at either a blue shark or a bull shark (depending on whether you went by weight or length). So even though there is a great variety in terms of length in requiem sharks, they, with the exception of the Tiger Shark, tend to be small to mid sized sharks.

There was a train of thought in the earlier days of shark research that the Hammerheads were true requiem sharks, but they are now regarded as viviparous but not a a true requiem shark.

The larger modern sharks such as the Whale Shark, Basking Shark, Great White Shark, Megamouth Shark, Greenland Shark, Sixgill Shark and the Mako are all ovoviviparous.

If we take all that and try to put what we know of modern sharks onto what may have existed millions of years ago, then our current level of knowledge would suggest that the biggest sharks were again ovoviviparous, and that if there were requiem sharks about, then they were mostly in the small to mid size range.

Alvin T. Grey

Kess73 wrote: »

It would be very very difficult to prove that any prehistoric shark was a true requiem sharks.


People can make guesses based on what they know of modern requiem sharks, but there is nothing to show that there were sharks that gave birth to live fully formed young back then.



The biggest requiem shark nowadays is the Tiger shark, and the next biggest would have you looking at either a blue shark or a bull shark (depending on whether you went by weight or length). So even though there is a great variety in terms of length in requiem sharks, they, with the exception of the Tiger Shark, tend to be small to mid sized sharks.

There was a train of thought in the earlier days of shark research that the Hammerheads were true requiem sharks, but they are now regarded as viviparous but not a a true requiem shark.

The larger modern sharks such as the Whale Shark, Basking Shark, Great White Shark, Megamouth Shark, Greenland Shark, Sixgill Shark and the Mako are all ovoviviparous.

If we take all that and try to put what we know of modern sharks onto what may have existed millions of years ago, then our current level of knowledge would suggest that the biggest sharks were again ovoviviparous, and that if there were requiem sharks about, then they were mostly in the small to mid size range.

I seem to recall somewhere that Meglodon was not of the same line as Great Whites. More of the line of Tigers.
Animals resurected or something like that. - But take everything you see on Discovery with a large pinch of salt. It's like Wikipedia, if it isn't verifiable from an independant source, then it's fishy (pun not intended)

Galvasean

Last I heard megalodon's closet relation was the mako shark, but they seem to change this every week. There is still raging debate on whether it should be called Carcharodon megalodon or Carcharocles megalodon. To save hassel most just say C. megalodon. So scrutinizing was the research that the modern great white (carcharodon carcharias) seems to be getting shuffled about in terms of clasification too.

Adam Khor

But I think they did find a Megalodon skeleton (in Peru, I think) and it was a lamnid after all, very similar to the Great White Shark. No Sand Tiger-like type as some people suggested (which makes sense because such a huge shark with a Sand Tiger-like body would be very slow IMHO, and we know this thing was hunting whales...)

Galvasean

Dunno about a full skeleton but some vertebrae were found in Europe. Not sure if i was enough to determine for sure exactly what type of shrk megalodon was.
I recall seeing a fully restored skeleton in a museum display, but it is about 95% guesswork.
Of course, if it was proven to be a lamnid taht doesn't rule out the mako theory.

Kess73

Galvasean wrote: »

Last I heard megalodon's closet relation was the mako shark, but they seem to change this every week. There is still raging debate on whether it should be called Carcharodon megalodon or Carcharocles megalodon. To save hassel most just say C. megalodon. So scrutinizing was the research that the modern great white (carcharodon carcharias) seems to be getting shuffled about in terms of clasification too.

Which would still be an ovoviviparous shark.

Kess73

Alvin T. Grey wrote: »

I seem to recall somewhere that Meglodon was not of the same line as Great Whites. More of the line of Tigers.
Animals resurected or something like that. - But take everything you see on Discovery with a large pinch of salt. It's like Wikipedia, if it isn't verifiable from an independant source, then it's fishy (pun not intended)

The man who was pushing the hardest for the requiem shark classification for the Meg was Steve Alten. It tied in nicely for him as he had the Meg given birth to ready to start killing straight away offspring in his Meg books.


He is the same guy who tried to fake his giant eel theory for another of his books, The Loch, by placing dead conger eel on the shore of Loch Ness as part publicity stunt, part this is real.

Galvasean

Kess73 wrote: »

Which would still be an ovoviviparous shark.

I know.

Kess73 wrote: »

The man who was pushing the hardest for the requiem shark classification for the Meg was Steve Alten. It tied in nicely for him as he had the Meg given birth to ready to start killing straight away offspring in his Meg books.


He is the same guy who tried to fake his giant eel theory for another of his books, The Loch, by placing dead conger eel on the shore of Loch Ness as part publicity stunt, part this is real.

He is also the only person I know of (over fifteen) that 'thinks' megalodon lived at the same time as Tyrannosaurus and 'thinks' megalodon still exists alive and well today.
A hack of the highest order.

Rubecula

First I have heard of him A Jack H. of the sea methinks.:mad:

Kess73

Rubecula wrote: »

First I have heard of him A Jack H. of the sea methinks.:mad:

He is nowhere near as bad as Horner to be fair. Alten is a fiction writer who tries to drum up sales with his waffle to the media, Horner speaks as if he is some kind of authority on the topics that he trolls people with.I do enjoy some of his books, the Meg series and The Loch were pulpy fun as long as you checked your brain at the door. Treat his books as creature features and they are worth reading.


What was more worrying was the fact that Discovery and a few other channels ran programmes that took some of what was in the books as researched fact.


Although his eel theory for Loch Ness is not without some grounding in fact, but he pretty much made some massive jumps in terms of assumptions and ignored a lot of the known basics about the species he was talking about.

Kess73

Galvasean wrote: »

I know.



He is also the only person I know of (over fifteen) that 'thinks' megalodon lived at the same time as Tyrannosaurus and 'thinks' megalodon still exists alive and well today.
A hack of the highest order.

If a white Meg tooth gets found, then I might start to believe that one is alive today or that it died in recent times, but until that moment there is nothing at all to suggest that they are still alive.

Galvasean

I won't believe it until my father is out fishing on his small boat and is killed by a megalodon. Thus, in true B-movie style, I swear an oath of vengeance.

Wibbs

Be brill if they were around but I doubt it. http://web.ncf.ca/bz050/megalodon.html

Other giant sharks undiscovered in the deep ocean I can imagine alright.

Galvasean

Nothing a whole lot bigger / more ferocious than the deep sea sleepers I'd imagine.