北京治疗白癜风多少钱一次 http://m.39.net/pf/a_4527139.html

小型恐龙曾经生活在今天的蒙古和中国北部的沙漠中。它们强大的夜视能力和强大的听力使它们在夜间成为致命的捕食者。

[1]Predator：n.[动]捕食者；[动]食肉动物；掠夺者

[2]Skull：n.头盖骨，脑壳

[3]Owl：n.猫头鹰；枭；惯于晚上活动的人

[4]Lightweight：n.轻量级（拳击手）；比通常重量轻的人或东西；无足轻重的人（或事）

adj.轻量的；给人印象不深的；无足轻重的；比通常重量轻的；浅薄的

[5]Cretaceousperiod：白垩纪（地质年代中中生代的 一个纪）

[6]Paleontologist：n.古生物学者

[7]Dig：vt.挖，掘；探究

vi.挖掘

n.戳，刺；挖苦

[8]Nocturnal：adj.夜的；夜曲的；夜间发生的。（nocturn：n.（天主教）夜祷）

[9]Mammal：n.哺乳动物

[10]Lizard：蜥蜴

[11]Insect：n.昆虫；卑鄙的人

[12]Lagena：n.细颈瓶；壶

[13]Curve：n.曲线；弯曲；曲线球；曲线图表

vt.弯；使弯曲

vi.成曲形

adj.弯曲的；曲线形的

[14]Sack：n.麻布袋；洗劫

vt.解雇；把……装入袋；劫掠

[15]Reptile：n.爬行动物；（非正式）卑鄙的人

adj.爬行动物的；卑鄙的

[16]Barn：n.谷仓；畜棚；车库；靶（核反应截面单位）

vt.把……贮存入仓

[17]Sclera：n.[解剖]巩膜

DinosaursEnjoyedNightlife,Too

SmalldinosaursoncelivedinthedesertintodaysMongoliaandnorthernChina.Theirgreatnightvisionandstronghearingmadethemdeadlypredators[1]duringthenighttime.

ScientistssaidThursdaytheyhavefoundacircleofbonesaroundtheeyeofadinosaurcalledShuvuuiaDeserti.Theboneswereinsidetheskull[2],whichholdsthehearingorgan.Scientistssaythedinosaurhadhearingandsightabilitiesmuchlikeanowl[3],meaningitcouldhuntinthedark.

Theirstudywaspublishedinthejournal,Science.Theresearchshowedthatmostpredatorydinosaurshadgoodhearing,buttheirsightworkedbestduringthedaytime.TheShuvuuia,however,lovednightlife.

Thetwo-leggeddinosaurwasthesizeofalargebirdandweighedaboutasmuchasahousecat.Ithadmanysmallteeth,likepiecesofrice.Itwaslightweight[4]andlivedduringtheCretaceousPeriod[5],about75millionto81millionyearsago.

RogerBensonisapaleontologist[6]fromtheUniversityofOxfordwhohelpedwritethestudy."Itssuchastrangeanimalthatpaleontologistshavelongwonderedwhatitwasactuallydoing,"hesaid.

Itsmid-lengthneck,smallhead,andverylonglegs,madeitlooklikeanunusualchicken.Butunlikebirds,ithadshort,strongarmswithalargeclawontheend,whichwasusefulfordigging[7].

JonahChoiniereisapaleontologistatWitsUniversityinSouthAfricaandthestudysleadauthor.

"Shuvuuiamighthaverunacrossthedesertfloorundercoverofnight,usingitsincrediblehearingandnightvisiontotracksmallpreysuchasnocturnal[8]mammals[9],lizards[10]andinsects[11],"hesaid.

Theresearchersalsolookedatastructurecalledthelagena[12].Thelagenaisacurved[13]sack[14]thatsitsinanareaofbonesaroundthebrain.Itisconnectedtothepartoftheearthatletsreptiles[15]andbirdskeepbalanceandmovetheirheadswhilewalking.Thelongerthelagena,thebetterhearingananimalhas.

Thebarn[16]owlcanhuntevenintotaldarknessandhasthelongestlagenaofanylivingbird,relativetoitssize.Shuvuuiaalsohasaverylonglagena,almostthesameinrelativesizetoabarnowls.

TheresearchersalsofoundthatShuvuuiahadaverywidescleral[17]ring--tinybonesthatcircletheeyeball.Theringslargesizemeansthatitwasabletoseeindarkness.

Choinieresaidthathepreviouslythoughtthatduringtheageofdinosaurs,thenightwasusedbymammalsto