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Dinosaurs of Past
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What's Wrong With This Picture? An Audio Critique
Thomas Holtz, a paleontologist for the University of Maryland, reflects upon what has changed, and stayed the same, since our 20th-century dinosaur coverage.
Plate Armor of the Roofed Lizard Protected It From the Sharp Teeth of a Flesh-eating Assailant The array of thin-edged plates and horns was the only defense of the vegetarian
. Into this busy feeder’s tiny mouth went a steady succession of plants, cut off with its beaked jaws to sustain a body 25 feet (7.62 meters) long. Its brain cavity was exceedingly small. The ferocious, nose-horned
walked upright on its hind legs—a trait of all carnivorous dinosaurs. Small front legs were free to seize prey or fight. ]]>
Harmless and Stupid, The Grotesque
Asked Only to Be Left in Peace Long-tailed and long-necked, these giants attained a total length of 75 feet (22.86 meters) or more. Depsite their great size, they could not fight well and had very small brains. They belonged to the vast family of dinosaurs, which roamed the earth during the Age of Reptiles, from 60 to 200 million years ago. Scientists put the weight of a full-grown
at about 25 tons (22.7 metric tons) and estimate his normal diet at about 700 pounds (317.5 kilograms) of leaves or plants daily.]]>
Egg-Laying Dinosaurs of Mongolia Grew Broad, Bony Collars to Save Their Own Necks An American Museum of Natural History expedition, led by Dr. Roy Chapman Andrews, in 1922, found a whole nest of eggs, left where they had been deposited millions of years ago by a female
. Some had been crushed by sand. All had turned to stone. The elated explorers brought back from Mongolia not only the eggs but a series of skulls, ranging from the embryo to the full-grown reptile, which may be seen at the Museum in New York.]]>
Six Feet (1.8 Meters) of Head, Horns, Spines, and Collar Look Ferocious, But on the Mild-mannered Crowned Lizard It Was All Bluff Even the formidable beak of the
was used only to cut foliage. The beast was a vegetarian and a landlubber. Safer was the upright
(pair at right). When danger threatened on land, this dinosaur could take to the water, wading, or swimming to safety. The bony growth from the back of its head was a singular feature. For food this reptile gathered soft, moist marsh plants in its duck-like bill.]]>
Excerpt from original story “Fleshed out at four feet (1.2 meters) tall and 150 pounds (68 kilograms),
was perfectly equipped to be a warm-blooded predator: powerful hind limbs for running down the quarry, good vision for coordination, hands articulated for grasping, pivoting hind talons for slashing, and a tail with long tendons for dynamic balance during the attack.”]]>
Excerpt from original story “In
, an air passage ran from the nostrils through the bill, up into the crest, and exited in the back of the mouth. The passage may have allowed breathing while eating. This would have been an advantage had the animal been a constant feeder, as the large battery of teeth suited to grinding suggests.”]]>
Excerpt from original story “For many it is
, also known as
, that springs to mind when they think of dinosaurs. For paleontologists, this 70-foot (21.3 meters), 30-ton (27 metric tons) beast and its ilk present serious problems for thinking all dinosaurs could internally regulate their body temperatures as do mammals.”]]>
Excerpt from original story “…the armored
had emerged as an ambling fortress with mouth parts uniquely adapted to feeding on fibrous plants like palms. The turtle-like beak could rip fronds, then teeth specialized for shearing could chop them fine enough to swallow.”]]>
Excerpt from original story “A champion turkey would match in size the curious
, an early dinosaur of about 200 million years ago. Unlike most herbivores that had only one sort of teeth, it had three kinds. Front teeth were adapted to biting or nipping, followed by a pair of canines, used in mammals for tearing, and rear teeth for chewing—a mammal-like system for efficient processing of large amounts of food.”]]>
Excerpt from original story “What ran like an ostrich, looked like an ostrich, and maybe even lived like an ostrich?
, the ‘ostrich mimic’ of about 80 million years ago. Although probably carnivorous, the dinosaur had no teeth, leading to speculation that it may have eaten, among other things, the eggs of fellow dinosaurs.” ]]>
and Pigeon From section “Dinosaur to Bird: The Missing Link” “When compared to the skeleton of
, a small theropod dinosaur, that of
was essentially similar. But besides having longer forelimbs, it had two features critical to classification as a bird: a wishbone, and, of course, feathers. The skeletal differences were subtle, and in one case, an
was mistakenly identified as a dinosaur for twenty years before the error was realized.”]]>
Carcharodontosaurus guards its kill against
. Unearthed from a slope in the Kem Kem, a skeleton of the smaller predator revealed a quick, two-legged creature measuring 25 feet (7.62 meters) long. Nearby sediment gave up more evidence. Fossil remains of crocodiles, turtles, and crustaceans—as well as petrified wood—suggest that life and habitat thrived in the region some 90 million years before humans walked the horizon.]]>
Oviraptor, a beaked dinosaur that resembles an ostrich with a tail, returning from its nest and feeding its young just like a mother bird. That’s what scientists picture after the spectacular find in Mongolia of the remains of a nesting dinosaur.]]>
Rahonavis swoop in to scavenge their share. ]]>
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