The extra finger present in early restorations and reconstructions was eventually lost. Curiously, though, the first complete forelimb of Tyrannosaurus rex was not found until No one was surprised by the fact that there were only two fingers, but this confirmation is a small lesson in the way paleontology works. Comparative anatomy is one of the cornerstones of the science, and paleontologists are constantly comparing the bones of different creatures to gain insights into the anatomy of organisms that are incompletely known.
If our knowledge of a fossil species is incomplete but we know a good deal more about closely related forms, then the anatomy of those relatives can help us fill in the gaps. Though Tyrannosaurus has been the most celebrated of the tyrant dinosaurs, reconstructions and restorations of the enormous carnivore have historically owed debts to more complete skeletons of its cousins Albertosaurus and Gorgosaurus. Riley Black is a freelance science writer specializing in evolution, paleontology and natural history who blogs regularly for Scientific American.
Feedloader Clickability Everybody knows that Tyrannosaurus had small arms tipped in only two fingers. But which digits? The theropod and bird digits failed to match up if you number the digits from 1 to 5 starting with the thumb. Theropods looked like they had digits 1, 2 and 3, while birds have digits 2, 3 and 4. That mismatch failed to support the widely accepted evolutionary link between dinosaurs and birds.
Now, newly described fossilized hands from a beaked, plant-eating dinosaur, called Limusaurus inextricabilis , reveal a transitional step in the evolution of modern wings from dino digits. The finding could resolve a debate over which fingers ultimately became embedded in the wing. The remains of the dinosaur were discovered in the Junggar Basin of Xinjiang, in northwestern China.
The deposits date back some million years. He and several colleagues have described the theropod dinosaur in the June 18 issue of the journal Nature. Jack Conrad, vertebrate paleontologist at the American Museum of Natural History in New York, calls the finding a "spectacular discovery.
The dinosaur was a ceratosaur, which is the group name for the earliest theropods. The largest known ceratosaur, Ceratosaurus nasicornis , boasted a length of up to 25 feet 8 meters , and showed off a prominent nasal horn. Stretching no more than 5 feet 1. But they were powerful, capable of lifting pounds. I suspect they may have used them for holding onto a mate an old theory or grasping the flesh of a dead dinosaur.
Q: How did T. Did it sleep standing up? I don't know if it snored, but it probably roared when awake, and one Japanese scientist thinks it sounded like a big belch. It probably had bad breath from eating rotting meat and not brushing between meals! Q: How much food could a T. A: We can't be sure. Big meat-eaters today like lions eat a lot at one time and then might not eat again for a week!
Maybe it ate a few hundred pounds of triceratops one day and then didn't eat again for a while. We'll never know. Q: Do you think T. A: It is likely that they were both. Big carnivores today, from lions on down, are inefficient hunters and scavenge more often. It's more energy efficient. There were huge herds of triceratops and duckbills in T. Q: Did the T. A: Scientist believe that T. That means it ate mostly animals that were already dead. Q: How do we know that T. A: Mammals are the only animals that have hair.
Since dinosaurs were not mammals, we know there was no hair on T. Q: Do you know if Tyrannosaurus rex always had that name?
It was also, mistakenly called dynamosaurus, but the name Tyrannosaurus rex, which means tyrant lizard king, is the one that stuck. Q: Have any eggs been found from T. A: No, not so far. Q: Is it true that a T. What do we know about T. A: It's probably not true. Its skull was wide enough for both eyes to focus on the same object, giving it good depth perception. Q: Could an allosaurus kill and eat a T.
It would have been a bloody battle, but T. It is bigger, with far more powerful jaws, and is more agile. Even though it had such runty arms and one less finger than allosaurus, T. Q: What is the difference between allosaurus and Tyrannosaurus rex? A: Tyrannosaurus and allosaurus are both carnivorous dinosaurs known as theropods. Allosaurus is much older, occurring in late Jurassic rocks, while Tyrannosaurs is two to three times as large and occurs in the late Cretaceous rocks about 80 million years younger.
Allosaurus is primitive, with a relatively long hand with three fingers, whereas Tyrannosaurus has a reduced hand with only two functional fingers. There are a lot of subtle differences in the head, backbone and ankle that suggest Tyrannosaurus is more closely related to modern birds than allosaurus.
This is a question that a lot of paleontologists have been thinking about and working on in the last 3 or 4 years. Tim Rowe. Q: Is there a dinosaur that can kill a T. A: I don't think anything killed a T. We found a T. A pack of Utahraptors might have been big enough, even though each is half T. But Utahraptors were mean enough to have killed a T.
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