首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
Once found almost entirely in the western United States and in Asia, dinosaur fossils are now being discovered on all seven cont
Once found almost entirely in the western United States and in Asia, dinosaur fossils are now being discovered on all seven cont
admin
2011-02-11
27
问题
Once found almost entirely in the western United States and in Asia, dinosaur fossils are now being discovered on all seven continents. A host of new revelations emerged in 1998 that promise to reshape scientists’ views of dinosaurs, including what they looked like and when and where they lived.
It is doubtful that Tyrannosaurus Rex had lips or that Triceratops had cheeks, says Lawrence Witmer, an assistant professor of anatomy at Ohio University in Athens, Ohio. He reached its conclusions by using high-tech computerized axial tomography (CT or CAT) scans along with comparative anatomy studies. For example, the theory that Triceratops and similar dinosaur species had cheeks was based on past comparisons with mammals such as sheep. But Witmer’s careful analysis found the structure of the triceratops jaw and skull made it more likely that Triceratops had a beak like that of an eagle. Witmer said that scientists should use birds and crocodiles as models when researching the appearance of dinosaurs.
In early October scientists announced that they had confirmed the discovery of a new type of ceratopsian dinosaur. The dinosaur’s bones, found in New Mexico in 1996, are forcing paleontologists to rethink their theories about when ceratopsians migrated to what is now North America.
Scientists previously thought that ceratopsians, the group that included the well-known Triceratops. arrived in North America from Asia between 70 million and 80 million years ago. During this time, the late Cretaceous Period. the earth’s two supercontinents—Laurasia in the north and Gondwanaland in the south—were in the process of pulling apart, cutting dinosaur populations off from each other and interrupting migratory patterns.
The fossilized bones, found by paleontologist Doug Wolfe of the Mesa Southwest Museum in Arizona, date to about 90 million yeses ago. This could mean that ceratopsians originated in North America and migrated to Asia rather than the reverse, paleontologists said.
An expedition from the Universities of Alaska in Anchorage and Fairbanks has discovered a region in remote northern Alaska so rich in fossilized dinosaur tracks that team members dubbed it the "dino expressway". The trampled area was found during the summer of 1998 on Alaska’s North Slope near the Brooks Range.
The team found 13 new track sites and made casts from the prints of five different types of dinosaurs. The rock in which the prints were found dates to more than 100 million years ago, or about 25 million years older than the previously discovered signs of dinosaurs in the Arctic region. Paleontologists said that the new findings provide important evidence that dinosaurs migrated between Asia and North America during the early and mid-Cretaceous Period. before Asia split off into its own continent.
Two rich fossil sites in the hills of Bolivia have been recently discovered, exciting paleontologists and dinosaur buffs. This discovery includes one of the most spectacular dinosaur trackways ever found.
The discovery of a large site in the mountain region of Kila Kila in southern Bolivia was announced in early October. Here scientists found the tracks of at least two unknown species of dinosaur. These included a large quadruped (four. footed) dinosaur that was probably about 20 m (about 70 ft) long.
The other site, located not far from the Bolivian city of Sucre, was uncovered in a cement quarry by workers several years ago but was not brought to paleontologists’ attention until the middle of 1998. The site features a vertical wall covered with thousands of dinosaur prints representing more than 100 different species. The tracks date back to between 65 million and 70 million years ago. Since dinosaurs are believed to have died out around 65 million years ago, the prints were likely made by some of the last dinosaurs on earth. Paleontologists hope to study the site and learn about the diet and physical characteristics of the dinosaurs that are represented there.
Witmer’s research leads people to believe ______.
选项
A、Tyrannosaurus Rex had lips and Triceratops had cheeks
B、dinosaurs might have looked tike mammals such as sheep
C、dinosaurs might not have looked like what we thought
D、dinosaurs must have looked like birds or crocodiles
答案
C
解析
根据第一段最后一句“new revelations ... to reshape scientist’s views of dinosaurs, including what they looked like...新的发现将改变科学家对恐龙长相的认识”即可基本判断C为答案,再结合第二、三段的主要内容可知, Witmer的研究表明恐龙的长相与过去科学家对恐龙长相的推测有很大差异,
转载请注明原文地址:https://kaotiyun.com/show/4AeO777K
0
专业英语八级
相关试题推荐
Americansoftentrytosaythingsasquicklyaspossible,soforsomeexpressionsweusethefirstlettersofthewordsinstead
Sincethelate1970’s,inthefaceofaseverelossofmarketshareindozensofindustries,manufacturersintheUnitedStates
1Betweenabout1910and1930,newartisticmovementsinEuropeanartweremakingthemselvesfeltintheUnitedStates.Amer
IthoughtofGodasastrangelyemotionalbeing.Hewaspowerful;Hewasforgivingyetobdurate,fullofwarmthandaffection.B
IthoughtofGodasastrangelyemotionalbeing.Hewaspowerful;Hewasforgivingyetobdurate,fullofwarmthandaffection.B
A、sufferedseverecasualtiesB、wereontherecentlyissuedlistofterroristsC、foughtwithSaudipoliceforcesD、werethoughtt
TheUnitedStateshasamajorracialproblemonitshands.True,Britainisfacingasimilarproblem,butforthetimebeingit
Onethingthatdistinguishestheonlineworldfromtherealoneisthatitisveryeasytofindthings.TofindacopyofTheEc
随机试题
[2005年,第6题]设函数,若f(x)在x=0可导,则a的值是()。
PMC模式是()的简称。
对某地下一层人防工程进行消防安全检查,下列检查结果中,不符合现行国家消防技术标准要求的有()。
2017年5月1日,高某到某酒店应聘工作;5月4日,高某在酒店老板的蒙骗之下订立了劳动合同,损失了一些劳动者应有的权利;2017年6月1日,有关部门裁定高某与酒店订立的劳动合同无效。劳动合同没有法律约束力的时间为()。
试述马克思主义关于人的全面发展学说。
李老师在高中音乐课《好汉歌》的教学目标当中写道:通过教师领唱,学生应和的方式感受歌曲的风格特点。这个教学目标很适合运用在高中音乐教学的哪一个模块?()
下列哪种监督是我国法律监督体系的核心?()
两院院士刘永坦及其团队研制的“新体制雷达”使中国对海岸线和领空的掌控力上升了一个台阶。为了表彰刘永坦院士,2019年1月8日,国家将2018年度国家最高科学技术奖和完全由个人支配的800万人民币奖金颁给了他。这告诉我们()。
犯罪中止:在犯罪过程中,自动放弃犯罪或者自动有效地防止犯罪结果发生的是犯罪中止。根据上述定义,下列情况中属于犯罪中止的是( )。
whatdoesthewomanfindinherbook?
最新回复
(
0
)