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
2010-02-20
115
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 promixse to reshape scientists’ views of dinosaurs, including what they looked like and when and where they lived.
It is doubtful that Tyrannosaurus Re 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 aial tomography (CT or CAT) scans along with comparative anatomy studies. For eample, 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 Meixco 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 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 epress-way". 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 pnnts 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.
Witmer’s research leads people to believe ________.
选项
A、Tyrannosaurus Re had lips and Triceratops had cheeks.
B、dinosaurs might have looked like 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
原文第二段中有It is doubtful that Tyrannosaurus Re had lips or that Triceratops had cheeks, says Lawrence Witmer。所以A不对。第三段中有 The theory that Triceratops and similar dinosaur species had cheeks was based on past comparisons with mammals such as sheep。所以B也不对。文中提到恐龙有鹰一样的嘴,且应以鸟和鳄鱼为模版,可知恐龙应是兼具几种动物的特点,不想人们以前所想象的那样。
转载请注明原文地址:https://kaotiyun.com/show/KcvO777K
0
专业英语八级
相关试题推荐
TherecanbenodoubtthattheemergenceoftheNegrowriterinthepost-warperiodstemmed,inpart,fromthefactthathewas
Thinkgolfis【C1】______game?Thinkagain.ResearchersincludingDebbieCrewsofArizonaStateUniversityandJohnMiltonofthe
人们经常说计算机是冷漠的,没有人情味的。但实际上很多人觉得与计算机相处比与人相处更舒服一些。计算机很耐心而且不会对使用它的人评头论足。它们高效而且可靠。不少学生羞于向老师表示自己有不懂的地方,但他们却乐于向计算机提问题。一些病人情愿向计算机而不是医生诉说病
Itisdifficulttogiveadescriptionof【C1】______becausetheyvaryfromstatetostateandcitytocity.Sometownsallowth
Well-preservedwrecksaboundintheBaltic,wherelowsalinityandcoldwaterslowdowndecay.TheseincludetheVasa,whichsan
A、Frenchcheeseandwhitewine.B、Salmon.C、Duck.D、ChefsaladandFrenchcheese.B
A、Noonecontrolsinformationordictatesbutthisoraltraditionisconstantlyself-correcting.B、Itisacultureinwhichever
A、Nearlyfivemillion.B、Thirtythousand.C、Overamillion.D、Innumerable.A
OfallthetroublesthatUStroopsmayfacewhentheycomehome,gettingtheiroldjobsbackshouldnotbeone.UncleSamsuppos
ToqualifytostudyinBelgium,itisessentialtomeetrelevantrequirementsin(1)academiccredentials,(2)linguisticskills
随机试题
叶片基部下延至叶柄成翼状的药材是
A.蒲黄B.地榆C.大蓟D.侧柏叶E.羊蹄
下列人体劳动强度参数中,不包括的是()。
根据流动性偏好理论,流动性溢价是远期利率与()。
小组工作的基本特性是()。
采用()所获得的考评结果,可用于决定一些非激励性的工资待遇。(2007年11月二级真题)
论述教师在教学中要依次完成的九大教学事项。
大学生社会实践活动的根本目的在于()。
与运动调节有关的黑质-纹状体通路的递质是
在党的第十二次全国代表大会上,邓小平同志提出的重大命题是
最新回复
(
0
)