恐龙绝灭主因：性别的温度决定与气候剧变

PRINCIPAL PEASONS OF DINOSAURS'EXTINCTION-TEMPERATURE-DEPENDET SEX DETERMINATION AND VIOLENT CLIMATIC CHANGES

许多爬行动物的性别由温度决定，经研究在现代龟鳖中尤为典型。恐龙具有与龟鳖类极其相似的繁殖习性，都是产卵于坑穴中并用沙土掩埋，靠阳光辐射温度使其孵化．因此可以推断恐龙的性别也并非由遗传基因控制，而与孵化期的气温有关：在高温时孵化为雌性，在低温时孵化为雄性．在白垩纪末全球发生气候剧变的情况下，由于气温过低，恐龙的后代中雄性占绝对优势，结果性别比例严重失调，使恐龙不能正常地完成繁衍活动。

any reptile' sex is determinated by temperature,which is perticylatly typical in living turtles. Dinosaurs relatively rambled turtles in their habits of reproduction. Dinosaurs as well as turban lay eggs in holes and bury eggs with sand and soil. Their eggs all are incubated by temperatrue of sunlight's radiation. Therefore, we can inter that sex ditferentiation of dinosaurs is controlled by incubation temperatrue during embryoggenesis instead of genes,and that a warm temperature produces females and a cool temperature Prodices males. When violent clinatic change took place and temperature was too low in the very end of Cretaceous, males were dominant in descendants of dinosaurs.As a result,the sex ratios of dinosaurs were seriously imbalanced. Finally,dinosaurs were not able to reproduce normally, which brought about their extinction.