CTET Paper-I English: Questions 294 - 294 of 294
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The fossil remains of the first flying vertebrates, the ptrerosaurs have intrigued paleontologists for more than two centuries. How such large creatures, which had wingspans from 8 to 12 meters, solved the problems of powered flight and exactly who these creatures were reptiles or birds are among the questions scientists have puzzles over.
Perhaps the least controversial assertion about the pterosaurs is that they were reptiles. Their skulls, pelvises and hind feet are reptilian. The anatomy of their wings suggests that they did not evolve into the class of birds. In pterosaurs, a greatly elongated fourth finger of each forelimb supported a wing like membrane. In birds the second finger is the principle strut of the wing. If the pterosaur walked or remained stationary, the fourth finger and with it the wing, could only turn upward in an extended inverted V-shape alongside of the animal’s body. Both the pterosaurs and the birds have hollow bones, a feature that represents a saving in weight. In the birds, however, these bones are reinforced more massively by internal struts.
Although, scales typically cover reptiles, the pterosaurs probably had hairy coats. The recent discovery of a pterosaur specimen covered in long, dense and relatively thick hair like fossil material was the first clear evidence that this reasoning was correct. Efforts to explain how the pterosaurs became air borne have led to suggestions that they launched themselves by jumping from cliffs, by dropping from trees or even by rising into light winds from the crests of waves.