论文部分内容阅读
在136年前,科学家在德国巴伐利亚省索伦霍芬地区中生代侏罗纪地层(距今约一亿四千五百万年)中,发现了一种形状大小如鸦、身覆羽毛的脊椎动物化石,这就是著名的始祖鸟。从此,与生物进化关系密切的鸟类起源问题,一直是科学家们探索的重要课题。始祖鸟虽被称为“鸟”,但是它身上有许多爬行动物的性状。比如口中有牙,有多节尾椎组成的长长的尾巴,肢骨的骨壁厚而不充气,前肢虽已称“翼”,但却有三个分开的指骨且指端有爪……。于是科学家们推断,始祖鸟并不能像现今世界上的鸟类那样自由自在地飞行,
136 years ago, scientists found a vertebrate in shape and size, such as a crow and a feather, in the Mesozoic Jurassic strata in the Sohrenhofen region of Bavaria, Germany (about 145 million years ago) Fossils, this is the famous Archeopteryx. Since then, the issue of the origin of birds closely related to biological evolution has always been an important topic explored by scientists. Archeopteryx, though known as “bird,” has many reptile traits. Such as teeth in the mouth, a long tail composed of many sections of the coccyx, limb bone wall thick and not inflatable, although the forelimb has been called “wings”, but there are three separate phalanges and fingers have claws ... .... Scientists then conclude that Archeopteryx does not fly as freely as birds in the world today,