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
Ceratopsia Ceratopsia thrived in North America and Asia during the Cretaceous Period (about 146 to 65.5 million years ago).
Ceratopsia Ceratopsia thrived in North America and Asia during the Cretaceous Period (about 146 to 65.5 million years ago).
admin
2013-04-25
67
问题
Ceratopsia
Ceratopsia thrived in North America and Asia during the Cretaceous Period (about 146 to 65.5 million years ago). Their name means "horned face" and indeed many of them did feature bony horns projecting from their skulls.
(A) The horns may look quite predatory, but Ceratopsians were
herbivores
1, so their horns were defensive in nature and may have been used to enforce order in the group.
(B) Not all Ceratopsians had horns, but all had beaklike mouths.
(C) The fossil record has revealed three distinct families among Ceratopsia: Psittacosaurids, Protoceratopsids, and Ceratopsids. Triceratops, a member of the Ceratopsid family, is probably the best known species of Ceratopsia. With its facial horns and neck display, it exhibits many of the features commonly associated with this dinosaur group.
(D) However, there are species of Ceratopsia that are quite different from the familiar Triceratops.
The Psittacosaurids comprise the Psittacosaurus
genus
2 and the Hongshanosaurus genus. Although not much fossil data are available for Hongshanosaurus, comparisons with Psittacosaurus can be made. Evidence indicates that both were roughly deer-sized bipeds dwelling in East Asia. Hongshanosaurus had beak points on both upper and lower jaws, while only the upper jaw of Psittacosaurus was pointed. Much more fossil evidence is available for Psittacosaurus species. At least one species had long quills along its back and tail. Researchers speculate these quills were used for display during mating or fighting. As early Ceratopsians, the Psittacosaurids had many anatomical features that would show up in similar or interestingly modified forms in later species, but none of the Psittacosaurids had the neck frills or facial horns that came to be associated with the Ceratopsians.
Although their name suggests that the Protoceratopsids were the first of this dinosaur group to have horned faces, they, in fact, lacked the well-developed horns of later species. While they more closely resembled the Ceratopsids on the whole, they were still relatively small and hornless. Protoceratops, a six-foot-long quadrupedal herbivore, is a representative Protoceratopsid. Fossil examples found in China and Mongolia show that it had a turtle-like beak and a neck frill, a version of which would show up among the more familiar Ceratopsids. While Protoceratops did have some knobby points on its skull, the points only slightly hinted at the impressive horns that appeared on the Ceratopsids.
With the arrival of Triceratops and other advanced Ceratopsids, Ceratopsia reached new levels of sophistication, variety, and size. All Ceratopsid fossils have been found in western North America and reveal that they were quadrupedal herbivores with beaked jaw tips and rows of teeth specialized for shearing. The family featured a remarkable array of horns, neck frills, and spines. These neck frills, manifesting in various shapes and sizes, probably were too thin to be practical as a defense against predator species, and researchers speculate that they were used during mating displays, for anchoring jaw muscles, for regulating body temperature, or for a combination of these purposes. Most Ceratopsids had two long brow horns and a short horn on the nasal ridge. Because the Ceratopsids were vegetarian and fairly large (up to 30 feet long and 10 feet tall), researchers think that the horns, along with the neck frills, largely served functions of competition, whether in displays or combat. Moreover, since intraspecific conflicts often are tests of strength rather than fights to the death, thin neck frills may have been sturdy enough to provide some protection during such confrontations.
There is evidence of Ceratopsian species that do not neatly fall into the familial categories as described. While these species appear closely related to Ceratopsia, they tend to be smaller and more primitive. Researchers have debated over recognizing a distinctly new Ceratopsian family or grouping these misfit species with an existing family. Psittacosaurids, Protoceratopsids, and Ceratopsids are the commonly accepted Ceratopsian families with established member species and defined characteristics. Despite some controversies over minor species, a view of the Ceratopsian families is a view of fascinating adaptations and development in a unique dinosaur group.
According to paragraph 1, why were Ceratopsians’ horns probably not used for hunting?
选项
A、Not all Ceratopsian species had horns.
B、Ceratopsians were vegetarians.
C、The behavior of similar species indicates other purposes.
D、Other physical features were better adapted for huntin
答案
B
解析
细节题 原文中没有直接说明角龙类不用犄角捕食猎物的原因,但是第一段提到角龙类因为有犄角而被误认为是食肉动物,但是实际上是食草动物。也就是说角龙类并不是利用犄角来捕食猎物的食肉动物,因此正确答案应该是B项。A项虽然是文章中提到的内容,但与问题无关。C项和D项的内容没有在文章中出现。
转载请注明原文地址:https://kaotiyun.com/show/cYyO777K
0
托福(TOEFL)
相关试题推荐
SECTION4Questions31-40Questions31and32Completethenotesbelow.WriteNOMORETHANTHREEWORDSAND/ORANUMBERforeac
Whichcolumnofthebarchartrepresentsthefiguresquoted?Wearflatshoes
TheprofessoralreadyknowssomethingaboutClarefromher______.
Studentsoncourseslastingoverayearareusuallygivenuntil______toleavethecountry.
Questions1-4AnswerthefollowingquestionsusingNOMORETHANTHREEWORDSAND/ORAFIGUREforeachanswer
outside
"ResearchMethodology"Closescientificmethodbasedonempiricalevidence(=(21))Findaresearchproblemorques
A、theysawitwasblack.B、theybelievedinthesupernatural.C、theywantedtheinventortobefamous.B
ENDANGEREDSPECIESAlthoughwecannotdoanythingabouttheplantsandanimalsthatarealready【31】________,wecandosomething
随机试题
在推进我国反腐倡廉建设的工作上,中国共产党一直坚持不懈地努力着,下列有关说法错误的是()。
表明患儿病情较轻的症状是()
A、金银花B、连翘C、大青叶D、蒲公英E、白头翁有“疮家圣药”之称的是
药物消除半衰期是指
(2006年)图8—39所示电路中,变压器视为理想的,R2=R1,则输出电压与输入电压的有效值之比为()。
建设项目总投资由固定资产投资和()两部分组成。
企业对行政管理部门实行定额备用金制度,定额为2000元,以库存现金拨付。月末,行政管理部门报销日常管理支出1500元。会计部门经审核准予报销,并以现金补足定额。
在本量利分析中,成本、业务量和利润之间的数量关系是建立在一系列假设基础上的。下列各项中,属于本量利分析的假设的有()。
设矩阵可逆,向量是矩阵A*的一个特征向量,λ是α对应的特征值,其中A*是矩阵A的伴随矩阵.试求a,b和λ的值.
•Youwillhearfiveshortrecordings.•Foreachrecording,decidewhatthespeakeristalkingabout.•Writeoneletter(AH)
最新回复
(
0
)