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
2011-01-02
42
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. Witmer was a leading researcher for a study on dinosaur anatomy that was presented at the annual meeting of the Society for Vertebrate Paleontology, which concluded on October 3 in Snowbird, Utah.
Witmer’s study reached its conclusions by using high-tech computerized axial to mograply (CT or CAT) scans along with comparative anatomy studies. For example, the theory that Triecratops and similar dinosaur species had cheeks was based on past comparisons with mammals such as sheep. But Witmer’s carful 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 ceratopsiaus 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 Gretaceous 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 eight-year-old Christopher Wolfe and his father, paleontologist Doug Wolfe of the Mesa Southwest Museum in Arizona, date to about 90 million years ago. This could mean that ceratopsians originated in North America and migrated to Asia rather than the reverse, paleontologists said. Doug Wolfe named the important new species of dinosaur Zuniceratops christopheri after his son.
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 in 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-foot-ed) dinosaur that was probably about 20m (about 70ft.) 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.
Scientists speculated that the tracks were made at the edge of a lake or swamp and were then hardened and preserved. The rock containing the tracks was then pushed into a vertical position over millions of years of geologic activity. Dinosaur eggs have also been found at the site, which paleontologists are working to preserve before it falls victim to erosion. Paleontologists hope to study the site and learn about the diet and physical characteristics of the dinosaurs that are represented there.
The passage focuses on ______.
选项
A、dincosaur’s geographical location
B、shifting views of dinosaurs
C、migration patterns of dinosaurs
D、geologic activity of Earth
答案
D
解析
该题问:本文的重点在哪一句?A项意为“恐龙的地理位置”,B项意为“对恐龙认识的改变”C项意为“恐龙迁移的模式”,D项意为“地球的地质活动”。关于本文的重点,可以从文章的首段找到线索: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.而且以后在比较中讲述了最近的几次重大发现,其结果是使科学家改变了许多原来对恐龙的认识,因此B项为正确选项。其他选项的内容文中都有涉及,都只是为主题服务的。
转载请注明原文地址:https://kaotiyun.com/show/nplO777K
0
专业英语八级
相关试题推荐
A、websetB、educationalschoolC、InternetportalD、foreigncompanyC
Wecomeindifferentcolors:red,black,white,yellowandbrown,haveavarietyofpoliticalsystems,socialsystems,religious
BurialCustomsinAncientEgyptEveryoneburnsfatdifferently.Thesearchfortheperfectdiethasneverbeenmorefrenzied.
将近九十年以后,毛姆在一次广播讲话里用自己的话重申了这个看法,并作了发挥。如果我没有理解错的话,毛姆先生说的是:人的头脑的基本构造之中具有一种东西,它非常喜欢甚至要求听人讲故事,讲一个开头、中间、结尾都齐全的故事。他还说,现代有些作家过分热衷于剖析心理和进
A、ScientistsattheKennedySpaceCenterareattemptingtogrowvegetablesthatcouldsurvive.B、Inthespecialcontainersplant
一切都是虚荣,人人皆爱虚荣,女人极其虚荣,男人也不甘落后——如果可能,他们则变本加厉。孩子也不例外,尤其是女孩子。其中一个正敲着我的腿,她想知道我对她的新鞋有何看法。坦白地说,这两只鞋并不怎么样,它们既不对称也没有曲线美,看上去有种无法形容的臃肿(同时我也
A、Avigorousprivatesector.B、Alegalframework.C、Aflexiblelabormarketandpromptserviceofdebt.D、Allabove.D
A、theUSOpenB、theAustralianOpenC、theFrenchOpenD、theHongkongChampionshipCA美国网球公开赛;B澳大利亚网球公开赛;C法国网球公开赛;D香港网球锦标赛。
奥林匹克运动会可以追溯到古代。希腊人喜欢各种运动,因为运动能使身体强健。他们每四年举行一次运动会,成千上万的人聚集在广阔的平原上,欣赏来自希腊各地的成人和儿童的竞技。运动项目有赛跑、摔跤、赛马、战车比赛等等。有成人的比赛项目,也有儿童的比赛项目。在
Environmentalscientistsobservethatitisofgreatsignificancetoprotectwildlifeandwildplacesffhumanbeingswanttosu
随机试题
用麻绳作起吊索具,轻便、易绑扎,但(),易磨损、磨烂变质。
克罗恩病最常见的并发症是
A.肾上腺素B.麻黄碱C.多巴胺D.去甲肾上腺素E.多巴酚丁胺防治过敏性休克可选用
(2006)图示梁在所示荷载作用下,其剪力图为下列何项?(提示:梁自重不计)
知识产权的基本特征包括( )。
下列滞报金的日征收率和起征点中哪项符合规定。()
下列关于个人教育贷款的表述,错误的是()。
国英公司是一家公开上市的企业,为了响应财政部、证监会等关于建立内部控制的有关文件的精神,决定大手笔建立公司内部控制系统,同时决定将此项工作委托国泰会计师事务所实施,在与该事务所接触时,国英公司的领导层提出如下建议要求国泰事务所参考:第一,内部控制作为该企业
王某给有关部门写信,反映自己关于推进素质教育的意见。这是公民依法行使()。
Youwillbeaskedtotalkaboutafamiliartopic.Afteryouhearthequestion,youwillhave15secondstopreparearesponsean
最新回复
(
0
)