National Geographic : 1942 Feb
Parade of Life Through the Ages surface is also responsible for the almost perfect preservation of the delicate skeleton of the bird-reptile and also the imprint of the actual wing and tail feathers. Without these precious imprints we should hardly dare to guess that the wings were al most like those of a modern bird or that a pair of feathers sprang from each of the long tail vertebrae. There are teeth in the tiny jaws, and clawed fingers on the wings-cer tainly an unusual set of characters to be in the possession of one diminutive creature, but significant for students of evolution. Beneath this unique feathered being a long jawed, goggle-eyed reptile hangs suspended by the sharp claws of the wings and hind feet. No feathers grace its ugly naked form, but the long-projected little finger of each hand carries a delicate membrane which is also con nected to the knee and ankle joints of this little flying nightmare. The slim tail is tipped by a kitelike membrane undoubtedly used as a rudder to guide the gliding wing-fingered Pterodactyl through the air. King-tyrant Lizard Was a Terrible Killer King-tyrant lizard-so we translate the name of the huge and terrible flesh eater Tyrannosaurus rex, the greatest and last, ap parently, of the carnivorous dinosaurs (Color Plate IX). The sinister appearance of this dreadful killer can hardly be appreciated unless one comes face to face with the actual mounted skeleton. Some twenty feet in height, long legged and long-tailed, the reptile towers up ward in most menacing fashion even though no flesh or skin now covers its mighty frame. A huge and terrible head, the jaws filled with long sharp teeth, is a fitting crown to the whole spectacular impression of the world's most formidable flesh eater, which once roamed the Hell Creek region of Montana. An upright fast-walking dinosaur, Tyran nosaurus rex had long hind legs and strangely birdlike feet, which gave the reptile an im mense stride. But the little front legs and feet seem out of place on so huge a body. Indeed, they are so small that they could have been of little use and appear to be merely degenerate remnants of much more powerful limbs in the earlier types. To the lesser dinosaur species which roamed the region inhabited by Tyran nosaurus, the sight of the enormous form of this rapacious beast must have been a signal for instant flight or certain annihilation. Undoubtedly two males of the species would sometimes indulge in a Gargantuan tussle for supremacy, but such a battle probably ended in quick retreat by the weaker animal. A combat between two such vast brutes must have been a sight worth witnessing, as the contestants whirled and threshed about, their fearful mouths agape and the long tails and massive legs entangled in a maze of swift evo lutions. The sword of a coming doom, however, hung over the heads of all this mighty race, so soon to give place to the tiny warm-blooded mammals of a later day. Changing conditions to which they could not adapt themselves re sulted in their complete extinction at the close of the Cretaceous era. Epoch-making Eggs Found in Mongolia When in 1921-2 the American Museum of Natural History, in New York, sent out an expedition to collect fossils in Mongolia, it little expected to stumble upon what proved to be an epoch-making discovery in this field.* For many years scientists had considered the probability of the egg-laying habit among the various species of dinosaurs, but they were not prepared to discover in that far dis tant country so complete a confirmation of all their theories. Not only did this in trepid band (Roy Chapman Andrews, Walter Granger, George Olsen, and others) unearth one or two of these much sought and hitherto practically unknown rarities. They actually came upon whole nests in which the eggs, about the size of a large pear, were disposed just as the female dinosaur had deposited them millions of years before (page 143). Not all were perfect, of course, since many showed evidences of crushing by the weight of sand above them; but a surprisingly large number-except that they were now turned to stone-might well have been laid only yesterday. Here indeed was a find worth gloating over, particularly when in a short time the very species-perhaps the very individuals-of a new type of dinosaur which had laid those eggs also came to light under the skilled hands of the collecting party. To cap the climax, two embryos, perfectly encased within the shell, definitely connected the eggs with the skeleton, now doubly valu able because of this unique association. Protoceratops, the cause of all this scien tific rejoicing, was a fairly small dinosaur, about nine feet long. It was big-headed, hornless, and therefore armored with a de fensive collar over the neck as a protection against flesh-eating species. A series of skulls, * See "Explorations in the Gobi Desert," by Roy Chapman Andrews, NATIONAL GEOGRAPHIC MAGAZINE, June, 1933.