资源描述：
《malacoshare sohl nf 1969 the fossil record of shell boring by snails外语英文电子书》由会员上传分享，免费在线阅读，更多相关内容在教育资源-天天文库。
1、AM.ZOOLOGIST,9:725-734(1969).TheFossilRecordofShellBoringbySnailsNORMANF.SOHLPaleontologyandStratigraphyBranch,U.S.GeologicalSurvey,U.S.NationalMuseum,Washington,D.C.20242SYNOPSIS.ThepredatoryboringhabitcommontomanyrecentsnailsprobablyarosefirstinthePoli
2、nicinae(Naticacea)duringUpperCretaceous(Cenomanian)times(100millionyearsB.P.).InthefossilrecordthefrequencyofboredshellsincreasesgreatlyinrocksoflatestCretaceousageandbecomesmorewidespreadduringearlyTertiarytimescoincidentwiththemajordiversificationofthe
3、primarygroupsofboringsnails.TheboringsintheseCretaceousandTertiaryshellsshowthesamecharacteristicsofpreferenceofpenetrationinonepelecypodvalveratherthantheotherorinpositionoftheboringsiteontheshellthatarefoundinrecentshellassemblages.BoringsinPaleozoicbr
4、achiopodshells(230-550millionyearsold)thathavepreviouslybeenattributedtogastropodpredationarehereinattributedtootherbutunknownboringorganisms.InparttheseboringsarenotacceptedasevidenceofPaleozoicgastropodpredationbecauseitnecessitates:(1)Postulationofthe
5、separatedevelopmentofaboringhabitwithitsconcomitantdevelopmentofanaccessoryboringorganinagroupwhosedescendantsareallherbivores,and(2)Thedevelopmentofsuchahabithundredsofmillionsofyearsbeforetheappearanceofanyrelativesofpresentdayborers.Boreholesattribute
6、dtogastropodpreda-(1961,p.263)notesalsothattheTri-tionhavebeenreportedinfossilshellsoftoniidaeandDoliidaepresumablypene-suchdiversegroupsastheForaminifera,trateshellsbutbypoorlyknownmethods.Brachiopoda,Gastropoda,Pelecypoda,spi-BothFischer(1962,p.76)andR
7、eymentrorbidpolychaetes,echinoids,andos-(1967,p.34)citedtheNassariidae(Buc-tracodes.Thesereportsrangeinagefromcinacea)asactivedrillersofholesinshellstheCambriantotheHolocene,aperiodofbutgavenoreferencesorexamples.some550millionyearsbuttheoriginsofAboring
8、orexcavatinghabithasalsomostoftheearlyboringsinshellsarecon-beenascribedtosomemembersoftheEu-troversial.thyneura.Wachter(1927)andDegnerAmongexistinggastropodsthemostac-(1928)havenotedthatsomemembersoftiveborersbelongtothec
