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Giant Creatures; huge prehistoric beasts.

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Sadurian Mike
458266.  Mon Dec 15, 2008 8:34 pm Reply with quote

Although not all prehistoric creatures were enormous, a lot of them were. In addition to the usual dinosaurs (some of which were actually tiny), there were plenty of species that looked very much like creatures we would be familiar with, only much larger!

To kick off; Sarcosuchus ("flesh crocodile"). 12 metres and 8 tonnes* of reptilian carnivorous terror. Steve Irwin would have thought twice before tackling this beast (at least, one would hope so).

Sarcosuchus was around in the early Cretaceous (about 140 million years ago) and palaeontologists are divided as to whether it hunted like a modern-day crocodile, feeding on land-dwelling creatures coming down to the water, or whether it was more like a gharial and ate fish. The stumbling block is that the snout is narrower than that of modern crocodiles which suggests fish, but appears to have become far broader as the animal aged. Certainly, there were plenty of enormous fish in the waters at the time it lived, but its teeth did not overlap like you see in modern gharial teeth (acting as effective fish-catchers but vulnerable if attacking heavy land animals).

Possibly the largest crocodilian-like reptile** ever, Sarcosuchus may have been overshadowed by Deinosuchus, Purussaurus, or (the most likely contender) Rhamphosuchus. The problem is that complete fossil skeletons are unavailable, and so measurements are estimated from the fragments they have and based on the proportions of modern crocodilians.







*The proportions are estimated from the skull and partial spine fossils found.

**Sarcosuchus was not a crocodilian in the true sense of the classification. Instead, it belongs to a related branch, the Pholidosauridae. Good (if rather cruel) klaxon question, though.

 
nitwit02
458275.  Mon Dec 15, 2008 9:49 pm Reply with quote

Sarah Palin just wouldn't believe you Mike ....

 
Sadurian Mike
458278.  Mon Dec 15, 2008 9:55 pm Reply with quote

That's alright. If enough people stop believing in Sarah Palin, she ceases to exist.

 
Sadurian Mike
458279.  Mon Dec 15, 2008 10:09 pm Reply with quote

Pachycrocuta brevirostris was a giant hyena of the Mid- Pliocene to Mid-Pleistocene (3 million to half a million years ago).

Standing a metre tall at the shoulder it may have weighed up to 250lb or more, with a heavy build and the typically powerful jaws of modern hyenas. Although modern hyenas are now known to actively hunt their prey, the heavy build of the Pachycrocuta brevirostris suggests that it would have been less likely to chase prey for any distance and may well have been an opportunist scavenger.





Yes, that's a humanoid skull in there. Homo erectus, to be precise, in a scenario reconstructed using bite marks on the H. erectus skull.



(It looks almost cute in that reconstruction).

 
Starfish13
458340.  Tue Dec 16, 2008 5:33 am Reply with quote

My fave extinct thingy is called Smilodon.

Smilodon, sometimes called the sabre-toothed cat, lived between approximately 2.5 million to 10,000 years ago in North and South America. They are called "saber-toothed" for the extreme length of their maxillary canines. Despite the colloquial name of "saber-toothed tiger", Smilodon is not closely related to a tiger.



A fully-grown Smilodon weighed approximately 55-300 kilograms, depending on species. It had a short tail, powerful legs, muscular neck and long canines. Slightly smaller than a tiger, Smilodon was extremely powerful and was quite bear-like in build.

But what it is best known for is its massive canine teeth. They are the longest canines of the saber-toothed cats at about 17 cm (7 inches) long in the largest species Smilodon populator. They were probably built more for stabbing than slashing. Despite being more powerfully built than other large cats Smilodon actually had a weaker bite than something like a lion. However, due tothe srtenght of teeth over bone, it has a greater relative to the bite force. In addition it could also open its mouth to 120degrees.

 
Sebastian flyte
458367.  Tue Dec 16, 2008 6:39 am Reply with quote

Are the Galápagos Tortoises 'Geochelone elephantophus' prehistoric? My favorite prehistoric creatures are ammonites which is possibly quite dull with all those giant scary furred things that are competing for my attention. Some ammonites could be quite big though about 3 feet/ 1 Metre diameter Although parts of ammonites shell are used to date other fossils so they do their bit I suppose!

 
djgordy
458389.  Tue Dec 16, 2008 7:14 am Reply with quote

Sadurian Mike wrote:



Yes, that's a humanoid skull in there. Homo erectus, to be precise, in a scenario reconstructed using bite marks on the H. erectus skull.


Perhaps it was a prehistoric circus act that went horribly wrong. Ugg the cave man invents the "puts head into carnivores mouth" trick and simultaneously becomes the first recorded recipient of a Darwin Award.

 
Arcane
458395.  Tue Dec 16, 2008 7:30 am Reply with quote

Here is a link to some interesting Australian megafauna, living and extinct.

Dromornis is particularly terrifying!

http://en.wikipedia.org/wiki/Australian_megafauna

 
Lukecash
458750.  Tue Dec 16, 2008 2:41 pm Reply with quote

What color were the Dinosaurs?

"Green will give you Klaxon "

The answer is "We don't know" Color of the skin is determined by the pigmens and they are not preserved by Fossilization. Scientist have done their best "guesswork" based on modern reptiles.


Some however are have said to been feathered. There has also been the long argument weather or not that Dino's and Birds were related:

http://en.wikipedia.org/wiki/Feathered_dinosaurs

 
Sadurian Mike
458754.  Tue Dec 16, 2008 2:47 pm Reply with quote

Lukecash wrote:
The answer is "We don't know" Color of the skin is determined by the pigmens and they are not preserved by Fossilization. Scientist have done their best "guesswork" based on modern reptiles.

The famous "mummified" hadrosaur shows scale differentiation that suggests it was striped. No pigment survives, of course, but evolution being what it is, it is likely that dinosaurs had similar colour differentiation as modern creatures in similar environments.

Of course, one good reason for the trend in illustrating dinosaurs with interesting patterns and colours is that they look better on a reconstruction.

 
Sadurian Mike
458760.  Tue Dec 16, 2008 2:52 pm Reply with quote

Lukecash wrote:
Some however are have said to been feathered.

Some fossils definitely show feather-like impressions, and a lot of the others have been inferred. I'm all for it, personally, because it makes a hell of a lot of sense that smaller dinosaurs that lived in the (relatively cold) End Cretaceous period would have had some sort of thermal protection.

 
Sadurian Mike
458763.  Tue Dec 16, 2008 2:57 pm Reply with quote

reddygirl wrote:
Here is a link to some interesting Australian megafauna, living and extinct.

Dromornis is particularly terrifying!

http://en.wikipedia.org/wiki/Australian_megafauna

I've always been fascinated by the huge carnivorous birds that dominated the late Miocene.

 
djgordy
458806.  Tue Dec 16, 2008 3:47 pm Reply with quote

Lukecash wrote:
What color were the Dinosaurs?

"Green will give you Klaxon "

The answer is "We don't know"


We don't know that they weren't green though.

 
Dr. Know
458819.  Tue Dec 16, 2008 4:03 pm Reply with quote

How do we know they were reptiles from their skeletons?

 
Sadurian Mike
458824.  Tue Dec 16, 2008 4:24 pm Reply with quote

They weren't really reptiles as we think of them, they were dinosaurs. Differences are (probable) warm blood and the way that the legs are more upright, like a mammals, than stuck-on sideways like a lizard. They are certainly Reptilia (vertebrates that came from eggs but are not birds or mammals), but we need to distinguish between them and lizards and snakes.

There were reptiles living alongside them, but the dinosaurs were dinosaurs. They are classed as Reptilia but are a distinct subset of them, unless you use Bakker's Linnaean classification, in which case they are completely seperate from reptilia.

This difference is essential in realising that our current lizards and snakes did not evolve from dinosaurs, but that their ancestors lived alongside each other.

 

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