Wednesday, June 05, 2013

IGUANODON: Question Authority (1 of 2)


Incorrect view of Iguanodon

As only the second Dinosaur to be discovered, Iguanodon reflects the development of the science of paleontology. In fact when She was named by Gideon Mantell in 1825, “Dinosaurs” were still an unknown concept. He had named Her for her iguana-like teeth, and regarded her “thumb” spike to be a nose horn similar to an Iguana.
In 1842, Sir Richard Owen, a creationist, in order to rebut various theories of evolution, created the Dinosaur Order (Dinosauria) from Iguanodon, Megalosaurus, and Hylaeosaurus. In contrast to the prevailing thought that these extinct animals were Reptiles, Owen reconstructed Iguanodon as a huge four-footed Mammal. Meanwhile, Mantell had the revolutionary concept that Iguanodon was a plant eater, when naturalists at this time regarded Dinosaurs to be only giant carnivores.
            These varying images formed the first pictures of Iguanodon for the public. Depicted as a lumbering low-slung animal, Iguanodon was displayed with her “thumb” spike on her nose. The life-size reconstruction of Iguanodon, at the Crystal Palace in London in 1852, resembled an Elephant with sharp teeth. This particular depiction of her became firmly entrenched in the public’s mind.
            This image changed in 1878, when a group of Iguanodon fossils was discovered in a mine in Belgium. When these fossils were finally reconstructed, scientists realized that Iguanodon looked much different from what they initially thought. In his models, Louis Dollo presented her new image to the public. Resembling a giant Wallaby, Iguanodon stood upright on her hind legs, while balancing on her long tail. Dollo moved her nose horn to the end of her hand for her “thumb” spike. Dollo’s presentation of Her lasted for an hundred years.
            In the 1980s as paleontologists re-examined their ideas of Dinosaurs, they realized that they were wrong about Iguanodon. If She had sat on her tail, it would have broken in two. Meanwhile, other new discoveries revealed that Dinosaurs had stiff tails that they held high off the ground. Having a stiffened tail meant that Iguanodon could walk on two feet or four feet, as She chose. Since Iguanodon could do this, She could search for both low lying plants and ones at the tree tops.

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