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.
The word "comprise" in the passage is closest in meaning to
选项
A、include.
B、belong in.
C、result from.
D、assimilat
答案
A
解析
词汇题 comprise的意思是“包括;由……构成”,因此,include的意思与其最接近。
转载请注明原文地址:https://kaotiyun.com/show/0YyO777K
0
托福(TOEFL)
相关试题推荐
SECTION3Questions21-30Questions21-23Choosethecorrectanswer,A,B,CorD.
WhichpiechartshowstheagesoftheAsianstudentssurveyed?HowmuchdidAustralia’seducationexportsrisebylastyear?
WhatisthetitleoftheseriesofpresentationsthatDavidPricewillmake?【20】
WhatisthetitleoftheseriesofpresentationsthatDavidPricewillmake?【13】______
Whichcolumnofthebarchartrepresentsthefiguresquoted?Thebackisdifferentfromotherpartsofthebodybecause_____
WhatdidKlaraoriginallywanttodoherprojecton?WhatdidKlara’sfriendsuggestincludinginformationon?
Questions36-40Decidewhichstatementistrueineachcaseandwritethecorrespondingletteronyouranswersheet.
What3kindsofcontactsshouldyouhavemadeduringyourtimeabroad?What2methodscananalumniassociationusetokeepyo
A、theysawitwasblack.B、theybelievedinthesupernatural.C、theywantedtheinventortobefamous.B
Choosethecorrectletter,A,BorC.CourseFeedbackHirokothinksthatinthereadingclassesthestudent
随机试题
瓣简述领导者树立改革创新观念的必要性。
骨折线从梨状孔下方,牙槽突上方两侧水平方向延伸至上颌翼突缝自鼻额缝向两侧横过鼻梁、眶内壁、眶底颧上颌缝沿上颌骨侧壁达翼突
脓性指头炎处理不及时易引起
对层流净化特点的错误表述是
当企业面临激烈的市场竞争时,被迫的物流服务和物流成本策略常常是()。
大数定理是指在随机试验中,每次出现的结果不同,但是大量重复试验出现的结果的平均值却几乎总是接近于某个确定的值,即该事件发生的概率。根据上述定义,下列事件能够用大数定理解释的是()。
2014年1月份,烟酒及用品价格同比下降0.7%。其中,酒类价格下降2.0%,炯草价格上涨0.2%。衣着价格同比上涨1.9%。其中,衣着加工服务费价格上涨5.3%,服装价格上涨2.0%,鞋类价格上涨1.5%。家庭设备用品及维修服务价格同比上涨1.5%。其中
张:公司若能使雇员照顾好孩子,公司将有利可图,因为这些孩子将会成为公司未来的顾客、雇员甚至经理。因此,公司应当采取诸如发放白天托儿津贴之类的措施来方便父母亲们。李:但是,没有任何一个公司将会仅被他自己成员的孩子所惠顾,仅雇用自己雇员的孩子,仅被自己雇员的孩
(2014年真题)甲路过某饭馆时见万某酩酊大醉,便冒充万某的朋友上前将其扶走,到一偏僻的地方后,将万某随身携带的价值5000元的财物全部取走。甲的行为构成()。
TheMissAmericacelebration【C1】______asabeautycontestin1921,butnowpreferstoavoidsuch【C2】______sincebeautyisnolon
最新回复
(
0
)