Shieldcroc

Galvasean

Another giant (10 meter) bizarre prehistoric croc. Reminds me of a bigger version of Laganosuchus AKA 'Pancake croc'. I wonder if it is one in the same as Stomatosuchus?

Extrapolating from the size of shieldcroc's braincase suggests that the animal grew to lengths of 50 to 60 feet (15 to 18 meters), a size that Holliday called "pretty ridiculous." More likely, he said, those proportions are off and shieldcroc was closer to 30 to 36 feet (9 to 11 meters) long.

http://www.livescience.com/16896-giant-shield-croc-crocodile-fossils.html

Galvasean

I was wondering, why do the extrapolations of sizes of 50-60 feet seem so ludicrous to Holliday et al.? Gigantism in crocodilians during prehistoric times is hardly uncommon,



Those are some big crocs! :eek: Rhamphosuchus was in that upper size range too. Then there was Spinosaurus, a dinosaur trying it's level best to become a crocodile , which could have been 60 feet in length.

Adam Khor

Galvasean wrote: »

I was wondering, why do the extrapolations of sizes of 50-60 feet seem so ludicrous to Holliday et al.? Gigantism in crocodilians during prehistoric times is hardly uncommon,



Those are some big crocs! :eek: Rhamphosuchus was in that upper size range too. Then there was Spinosaurus, a dinosaur trying it's level best to become a crocodile , which could have been 60 feet in length.

I agree that there wouldn´t be anything "ludicrous" about a 15-18 meter long crocodilian. Paleontologists tend to be close-minded folks- and new fossil discoveries always force them to swallow their absolutes. (Remember when they said anything bigger than Pteranodon wouldn´t be able to fly? Or that anything larger than Brachiosaurus wouldn´t be able to stand on land?)

BTW, I think that Crocodylus porosus in the chart looks awfully small...

Allosaur

Adam Khor wrote: »

Paleontologists tend to be close-minded folks- and new fossil discoveries always force them to swallow their absolutes. (Remember when they said anything bigger than Pteranodon wouldn´t be able to fly? Or that anything larger than Brachiosaurus wouldn´t be able to stand on land?)

BTW, I think that Crocodylus porosus in the chart looks awfully small...

Yes, but isn't it wonderful the way the theories change drastically in light of new evidence. And it's one of the few (maybe only) field where there is room for the "gifted amature".

Galvasean

Adam Khor wrote: »

BTW, I think that Crocodylus porosus in the chart looks awfully small...

Indeed. Isn't he supposed to be 8 meters long?
In any case whose to say we've found the biggest specimens of the giant crocs? Look at modern alligators. Adults usually come in at about 5 feet but every now and again a monster of over 9 feet shows up. What if 'regular' Sarcosuchus are the ones we've found? Perhaps some truly monstrous beasts lurk hiding in the fossil record...

Adam Khor

Galvasean wrote: »

Indeed. Isn't he supposed to be 8 meters long?
In any case whose to say we've found the biggest specimens of the giant crocs? Look at modern alligators. Adults usually come in at about 5 feet but every now and again a monster of over 9 feet shows up. What if 'regular' Sarcosuchus are the ones we've found? Perhaps some truly monstrous beasts lurk hiding in the fossil record...

Exactly.

Badger02

I am not sure where your data on modern alligators comes from unless you are referencing the Siamese Alligators and not the American Alligators. A 5' AA is not even of breeding size yet and 9' is just barely getting there, even for a female. 12' to 15' males are common and 11' to 13' females are as well; they can be found in almost any healthy population. A really good size male would be upwards of the 17' to 18' range. Among the largest on record is a 19'2" from several years ago of which I have held the skull in my own little hands. If what you posted is simply a typo, my apologies.

Adam Khor

Badger02 wrote: »

I am not sure where your data on modern alligators comes from unless you are referencing the Siamese Alligators and not the American Alligators. A 5' AA is not even of breeding size yet and 9' is just barely getting there, even for a female. 12' to 15' males are common and 11' to 13' females are as well; they can be found in almost any healthy population. A really good size male would be upwards of the 17' to 18' range. Among the largest on record is a 19'2" from several years ago of which I have held the skull in my own little hands. If what you posted is simply a typo, my apologies.

Its Chinese alligator, not Siamese. Just saying.

Galvasean

Must have been mixing up my 'gators

Galvasean

Adam Khor wrote: »

Its Chinese alligator, not Siamese. Just saying.

Interesting fact I just read about the Chinese alligator - it has belly armour. I was not aware of that.

Kess73

Galvasean wrote: »

Indeed. Isn't he supposed to be 8 meters long?In any case whose to say we've found the biggest specimens of the giant crocs? Look at modern alligators. Adults usually come in at about 5 feet but every now and again a monster of over 9 feet shows up. What if 'regular' Sarcosuchus are the ones we've found? Perhaps some truly monstrous beasts lurk hiding in the fossil record...

The largest verified specimen was 6.3 meters so the chart is pretty accurate.

Adam Khor

The shield croc already has a name, Aegisuchus, which means... well, shield croc. Wikipedia states that if its proportions were similar to those of modern day crocodiles, it may have had a length of 15 to 22 meters!
It then goes on to say that "Aegisuchus was almost certainly not this long, for it would be much longer than the largest of crocodilians, including Deinosuchus, Gryposuchus, Purussaurus, and Sarcosuchus". Which sounds like nonsense to me- there is absolutely no rule written in stone saying that no crocodiles larger than those mentioned can possibly be found.

It seemingly had a strange circular boss on top of its head that may have been an eyespot to aid in courtship rituals (during which modern day crocs are known to raise their heads out of the water).



And here's a pic of a caterpillar with an anti-predator eyespot just because it looks so surreal:



And yes, the eyespot is actually on its butt.

dlofnep

The sad thing about the fossil record is that there's a great chance some of the most remarkable creatures that have ever lived will never be known to us.

steddyeddy

Adam Khor wrote: »

I agree that there wouldn´t be anything "ludicrous" about a 15-18 meter long crocodilian. Paleontologists tend to be close-minded folks- and new fossil discoveries always force them to swallow their absolutes. (Remember when they said anything bigger than Pteranodon wouldn´t be able to fly? Or that anything larger than Brachiosaurus wouldn´t be able to stand on land?)

BTW, I think that Crocodylus porosus in the chart looks awfully small...

Why is that man posing friendily with a series of large crocodiles?

Adam Khor

steddyeddy wrote: »

Why is that man posing friendily with a series of large crocodiles?

In my experience, crocodiles are surprisingly odourless. Maybe the poor dude is blind.

dlofnep

That Purussaurus is immensely huge! His skull size in comparison with the other supercrocs is off the charts.

Rubecula

steddyeddy wrote: »

Why is that man posing friendily with a series of large crocodiles?

He thinks they are LaCoste sleeping bags. He is about to climb inside one for a look around.


Strange how even the (frankly too big to meet in a dark alley) Crocodylus porosus looks small in comparison to the other crocs, but just compare him to the man. These things grew to huge sizes, and who is to say that in the future crocs could not do the same. It is, I think, all dependent on environment and food supplies.

PS.
The Nile crocodile or Common crocodile (Crocodylus niloticus) has been authenticated at 6.1 metres, with reports of 7 metres. And they are big beasties. (I think they are not a lot smaller than the big Salties ( Crocodylus porosus)

Adam Khor

Rubecula wrote: »

He thinks they are LaCoste sleeping bags. He is about to climb inside one for a look around.


Strange how even the (frankly too big to meet in a dark alley) Crocodylus porosus looks small in comparison to the other crocs, but just compare him to the man. These things grew to huge sizes, and who is to say that in the future crocs could not do the same. It is, I think, all dependent on environment and food supplies.

PS.
The Nile crocodile or Common crocodile (Crocodylus niloticus) has been authenticated at 6.1 metres, with reports of 7 metres. And they are big beasties. (I think they are not a lot smaller than the big Salties ( Crocodylus porosus)

As I've said before, American crocodiles (Crocodylus acutus) are no wimps either. They too reach 7 meters long, although they are, as a rule, less robust than similarly sized saltwater crocs. Still giants, though: