In almost all cases, the soft parts of fossils are gone for ever but they were fitted around or within the hard parts. Many of t

admin2014-06-13  32

问题     In almost all cases, the soft parts of fossils are gone for ever but they were fitted around or within the hard parts. Many of them also were attached to the hard parts and usually such attachments are visible as depressed or elevated areas, ridges or grooves, smooth or rough patches on the hard parts. The muscles most important for the activities of the animal and most evident in the appearance of the living animal are those attached to the hard parts and possible to reconstruct from their attachments. Much can be learned about a vanished brain from the inside of the skull in which it was lodged.
    Restoration of the external appearance of an extinct animal has little or no scientific value. It does not even help in inferring what the activities of the living animal were, how fast it could run, what its food was, or such other conclusions as are important for the history of life. However, what most people want to know about extinct animals is what they looked like when they were alive. Scientists also would like to know. Things like fossil shells present no great problem as a rule, because the hard parts are external when the animal is alive and the outer appearance is actually preserved in the fossils.
    Animals in which the skeleton is internal present great problems of restoration, and honest restorers admit that they often have to use considerable guessing. The general shape and contours of the body are fixed by the skeleton and by muscles attached to the skeleton, but surface features, which may give the animal its really characteristic look, are seldom restorable with any real probability of accuracy. The present often helps to interpret the past. An extinct animal presumably looked more or less like its living relatives, if it has any. This, however, may be quite equivocal. For example, extinct members of the horse family are usually restored to look somewhat like the most familiar living horses — domestic horses and their closest wild relatives. It is, however, possible and even probable that many extinct horses were striped like zebras. If lions and tigers were extinct they would be restored to look exactly alike. No living elephants have much hair and mammoths, which are extinct elephants, would doubtless be restored as hairless if we did not happen to know that they had thick, woolly coats. We know this only because mammoths are so recently extinct that prehistoric men drew pictures of them and that the hide and hair have actually been found in a few specimens. For older extinct animals we have no such clues.
According to the third paragraph, which of the following is true?

选项 A、A fossilized animal’s appearance is usually restored accurately.
B、It is difficult to restore some fossilized animals because they had no external parts.
C、The prehistoric elephants are hairless.
D、An extinct animal does not definitely look like its living relatives.

答案D

解析 推理判断题。观察四个选项:[A]项里的accurately很明显与全文意思相悖,本文一直在强调对古生物外貌进行复原所具有的难度,因此很多时候只能根据推测来进行;[B]项中的because they had no external parts不符合常理,任何动物都有外部组织,比如动物的皮毛,只是很多动物没有像贝壳一样的hard external parts;[C]的表述与原文完全相反,文中明确提到,现代的人根据史前人类所画的猛犸象。知道了其是长有长毛的;因此,只有[D]“灭绝的动物不一定跟活着的近亲相像”正确。根据文中所举的马的例子.可以证明这一点,所以[D]为答案。
转载请注明原文地址:https://kaotiyun.com/show/BpO4777K
0

最新回复(0)