200-million Years Old Dinosaur Species Discovered in South Africa
A newly discovered dinosaur species that roamed the Earth about 200 million years ago may help explain how the creatures evolved into the largest animals on land, scientists in South Africa said.
The Aardonyx celestae was a 23-foot- (7-meter-) long small-headed herbivore with a huge barrel of a chest. It walked on its hind legs but also could drop to all fours, and scientists told reporters that could prove to be a missing evolutionary link. Continue Reading »
The name dinosaur comes from the Greek words deinos (“terrible” or “fearfully great”) and sauros (“reptile” or “lizard”). The English anatomist Richard Owen proposed the formal term Dinosauria in 1842 to include three giant extinct animals (Megalosaurus, Iguanodon, and Hylaeosaurus) represented by large fossilized bones that had been unearthed at several locations in southern England during the early part of the 19th century. Owen recognized that these reptiles were far different from other known reptiles of the present and the past for three reasons: they were large yet obviously terrestrial, unlike the aquatic ichthyosaurs and plesiosaurs that were already known; they had five vertebrae in their hips, whereas most known reptiles have only two; and, rather than holding their limbs sprawled out to the side in the manner of lizards, dinosaurs held their limbs under the body in columnar fashion, like elephants and other large mammals.
Hunched in the Cretaceous grassland on a breezy afternoon, the hunting party halts a thousand yards from the Monoclonius. Downwind from the beast, they watch it graze in listless tranquility. It’s a youngster of the scattered herd, some two and a half tons of grayish green bulk, and in the low sunlight the single horn on its snout casts a shadow across its face.
The bull gator lay in the sand under the oak trees. A few days earlier he had been hauled out of a murky lake in central Florida. Researchers instantly named him Mr. Big. He was sofa-size, with fat jowls framing his head like a couple of throw pillows. He would have measured 13.5 feet (4 meters) if a rival hadn’t chomped the last foot off his tail.