首页
登录
职称英语
Once found "almost entirely in the western United States and in Asia, dinosa
Once found "almost entirely in the western United States and in Asia, dinosa
游客
2023-12-14
22
管理
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 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 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 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 Christopher after his son.
An expedition from the University 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 "dinosaur epressway". 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 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. [br] 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 maremals 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://tihaiku.com/zcyy/3272342.html
相关试题推荐
ThelargestriverintheUnitedKingdom,whichruns355kilometresandemptiesi
FormanyyearsitwascommonintheUnitedStatestoassociateChineseAmeri
FormanyyearsitwascommonintheUnitedStatestoassociateChineseAmeri
FormanyyearsitwascommonintheUnitedStatestoassociateChineseAmeri
ItappearsentirelyappropriatethattheUnitedStateswouldconsiderrestoratio
ForeignworksnotillegibletobecopyrightedintheUnitedStatesbeforethe19
StudentsofUnitedStateshistory,seekingtoverifythecircumstances1.___
StudentsofUnitedStateshistory,seekingtoverifythecircumstances1.___
StudentsofUnitedStateshistory,seekingtoverifythecircumstances1.___
StudentsofUnitedStateshistory,seekingtoverifythecircumstances1.___
随机试题
易燃易爆化学物品出厂时,必须有产品安全说明书。说明书中必须有经法定检验机构测定的
环刀法测定压实度试验中,须进行两次平行测定,其平行差不得大于()A.0.1g/
电风扇高速转动时,人们看到的不再是一扇一扇的叶片,而是一个整体的圆盘在旋转,这种
精益管理指变电运检验收工作坚持精益求精的态度,以精益化评价为抓手,(____),
下列关于培训结果层面的评估的说法错误的是( )。A.可以打消高层主管投资培训的
招标文件中,由于各种管理要求、管理价格的制定都具有(),所以过一段时间可能需要调
单线循环脱挂抱索器客运架空索道在吊具距地高度大于()时,应配备缓降器救护工具。
某点的真空压强为65000Pa,当地大气压为0.1MPa,该点的绝对压强为(
根据记账凭证登账,误将200元记为2000元,而记账凭证没错,应采用()进行更正
项目成本指标控制的工作包括:①采集成本数据,监测成本形成过程;②制定对策,纠正偏
最新回复
(
0
)