Posted on 02/13/2006 7:12:23 PM PST by NormsRevenge
THE biggest, and possibly the baddest predatory dinosaur of them all was not the fabled Tyrannosaurus rex, or even its slightly larger rival Gigantosaurus, but a long-jawed, sail-backed creature called Spinosaurus.
An examination of some newly obtained fossils shows that Spinosaurus stretched an impressive 17 metres from nose to tail, dwarfing its meat-eating relatives. As well as being longer than its rivals, Spinosaurus also had stronger arms with which to catch its prey, unlike the puny-armed T. rex and its ilk.
Until 10 years ago, T. rex held the mantle of the biggest predatory dinosaur. Of the 30 specimens collected so far, the largest and most complete is a fossil called Sue, kept at the Field Museum of Natural History in Chicago. She measures 12.8 metres long and is thought to have weighed 6.4 tonnes when alive 67 million years ago.
Enter Gigantosaurus, a meat-eating dinosaur that lived in what is now Argentina. Reconstruction of a partial skeleton indicated that it stretched 13.7 metres. It lived about 100 million years ago at around the same time as two other huge predatory dinosaurs were stalking other continents. The slightly smaller Carcharodontosaurus lived in Africa while Acanthosaurus lived in North America, the only one of the three dinosaurs for which we have more than a handful of fragmentary fossils. All three predators were closely related to Allosaurus, a 9 to 12-metre-long predator of a lighter build than T. rex which was common in North America 150 million years ago.
However, Spinosaurus has been casting its fearsome shadow over all these beasts for some time. German palaeontologist Ernst Stromer discovered the first and best specimen in 1912 in Egypt. He identified it as a long-snouted giant predator which he believed was bigger than T. rex, and published a detailed study of the bones, including a partial backbone with long spines on the vertebrae, which may have supported a sail. Stromer's fossils were obliterated when allied bombers hit a Munich museum in 1944. Since then, all that has been discovered are some specimens of related smaller spinosaurs, as well as some isolated bones of Spinosaurus itself.
But a new examination of two skull fragments of Spinosaurus has confirmed its early reputation. Cristiano Dal Sasso of the Civic Natural History Museum in Milan, Italy, and his colleagues analysed a snout the museum acquired from an Italian collector, and previously unidentified bones from the upper rear of the skull collected by the University of Chicago, both of which were originally unearthed in Morocco.
After measuring their sizes, he estimates that the 99-centimetre-long snout came from a skull 1.75 metres long. From what we know of the body shapes of other spinosaurs, Dal Sasso calculates that the new Spinosaurus was 17 metres long and weighed 7 to 9 tonnes (Journal of Vertebrate Paleontology, vol 14, p 888).
Spinosaurus lived alongside Carcharodontosaurus in Africa 100 million years ago, and like T. rex and Gigantosaurus was a theropod, the group of dinosaurs that gave rise to birds. But Dal Sasso says spinosaurs, with their very long and slender snouts are more like "theropods with crocodile mouths". Their long teeth interlocked to catch prey, and a sawfish vertebra stuck between a tooth socket and an emerging tooth in one fossil specimen supports the idea that Spinosaurus preyed largely on fish. Other specimens also suggest that spinosaurs had arms "strong enough to be used in catching prey", says Eric Buffetaut of France's National Centre for Scientific Research in Paris, who collaborated with Dal Sasso.
T. rex and Gigantosaurus "were doing very different things", says palaeontologist Larry Witmer of Ohio University in Athens. T. rex had puny arms, but its stout skull had massive banana-shaped teeth that could crunch through bone, where Giganotosaurus had a much more slender skull, with blade-like teeth to slice through flesh.
Earliest Tyrannosaur A "crowned dragon" that lived 160 million years ago was the great-grandaddy of the tyrant lizard king T. rex.
Two skeletons of the oldest known tyrannosauroid have been discovered in what used to be wetland in the Gobi desert of western China. The beast has been named Guanlong, or "crowned dragon", not because of its ferocity or its kinship with T. rex, but because it had an unusual prominent nasal crest on its head, which was probably an ornament used to display sexual prowess.
Xing Xu of the Institute of Vertebrate Paleontology and Paleoanthropology in Beijing and colleagues uncovered the nearly complete skeleton of a juvenile and the partial skeleton of a 3-metre long adult. The juvenile had died first and its skeleton sank into the mud of the wetland, where it may have been trampled by the adult before it too died (Nature, vol 439, p 715).
Tyrannosaurs only became giants late in their evolution. They spent the early part of their history as secondary predators in the shadow of allosaurs and spinosaurs, says Tom Holtz of the University of Maryland in College Park. Nine-metre-long giant tyrannosaurs didn't appear until about 80 million years ago, just 15 million years before an asteroid impact ended the reign of the dinosaurs.
When my oldest daughter was about eight she called the flying dinosaur a squawkasaurus.
I'd recommend a Weatherby 460..
T. Rex's rep just keeps slipping further. The last theory I heard was that T.Rex was probably a scavenger, not a predator.
But I can't remember if that new theory was ever debunked. They went back and forth with that one for awhile.
or a Barrett .50
I'd recommend something belt-fed or crew-served.
gas powered
Now that would be an interesting hunting experience. Well, only if you didn't mind humping a 20mm antitank rifle to get it.
Now dont forget the other explantion for dinosaur bones...that there really were not any dinosaurs roaming alive on the earth, but the devil just put those bones there, to mislead men....
1. TRex still has - hands down - the most powerful jaws ever seen in a terrestrial predator. Therefore, while the outcome can't be predicted, if TRex got the 'first bite in', it would have been curtains for the competition;
2. This ain't really news - there are at least 2 fairly complete Spinosaurus skulls in the hands of private collectors that measure in the neighborhood of 8 feet (!) in length. Dr. Thomas Holtz was telling me recently that he had reviewed one of them for an upcoming publication, so dinophiles - watch for it.
3. Even if a Spinosaur was 51 feet long, it would have been no match for a TRex. Spinosaurs were relatively slender fisheaters, with crocodile-like teeth and very thin and long jaws, which would have been a weak weapon against a muscular TRex. One chomp from the TRex's 'nutcracker' jaw and it would have been all over for Spino (The one in the JP III movie was a pure fantasy creature).
4. Lastly, TRex was NOT a scavenger (although we may surmise that it ocassionally DID scavenge as do all predators).
Andrewsarchus: about 4-5.5m long and standing about 1.8-2m at the shoulder
I'd still rather hunt this puppy. The largest land mammal predator ever.
A Ma Deuce for me, thank you.
Well, its either him or an Entelodont (an omnivorous rhino-sized pig with a BAD attitude and a mouthfull of hippo-like teeth)...
Nasty looking suckers, weren't they?
Please.
Anybody got stills of that Battle between those 2 Terribel Lizards???
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