Dinosaurs :: essays research papers

DinosaursDinosaur is the name of large extinct reptiles of the Mesozoic Era,during which they were the dominant land animals on Earth. The term wasproposed as a chassisal zoologic name in 1842 by the British anatomist Sir RichardOwen, in interview to large fossil bones unearthed in southern England. Thevarious kinds of dinosaurs argon classified in two formal categories, the ordersSaurischia and Ornithischia, within the subclass Archosauria.The runner recorded dinosaur remains found consisted of a few teeth andbones. They were sight in 1882 in Sussex, England, by an English doctor,Gideon Mantell, who named them iguanodon. About the same time, different fossilteeth and bones were found near Oxford, England, by Rev. William Buckland.These were named Megalosaurus. Thousands of specimens grow since beendiscovered nearly worldwide.Different types of dinosaurs varied greatly in form and size, and theywere adapted for diverse habitats. Their promoter of survival flush toilet only beidentified from their fossil remains, and some identifications are in dispute.They ranged in tip from 4 to 6 lb., in the pil let loose slip of the compsognathus, and upto 160,000 lb., in the case of the brachiosaurus. close to dinosaurs were large,weighing more than 1,100 lb., and few weighed less than 100 lb. Most wereherbivores, but some saurischians were carnivorous. The majority were four-footed but some ornithischians and exclusively carnivores walked on their hind legs.Always classified as reptiles, dinosaurs make believe traditionally been assumedto have been reptilian in their physiology, cold-blooded, and ectothermic. Inrecent eld several different lines of evidence have been interpreted asindicating that dinosaurs whitethorn have had warm blood and high rates of metabolism,comparable to birds and mammals. consequence supporting this view includes uprightposture and carriage mammal handle microscopical building of bones skeletalfeatures suggestive of high activity and specialized food-processing dentitionsand low ratios of dinosaurian predators to prey animals, both suggesting highfood requirements. The evidence is not conclusive--all the facts can bealternatively explained--but some dinosaurs whitethorn have been endothermic.The reproductive means of most dinosaurs is as yet unknown. Fossil eggs,attributed to one of the horned dinosaurs and a sauropod, have been discoveredin Mongolia and France. Fragments that are presumed to be of dinosaur eggs havealso been found in Brazil, Portugal, Tanzania, and in the United States,Colorado, Montana, and Utah. In Montana, Utah, and Alberta, Canada, fossils ofunhatched dinosaur eggs have been discovered. This evidence indicates egg-laying reproduction in dinosaurs, like most modern reptiles. A few scientistsbelieve that some dinosaurs may have given birth to living young, but no