Diversity fluctuations and biogeography of Ordovician brachiopod faunas in northeastern Spitsbergen

Bulletin of geosciences

Holmer LE¹  Hansen J¹ 

关键词: Ordovician;    brachiopods;    Spitsbergen;    biodiversification;    biogeography;   

DOI  :  

来源: Czech Geological Survey

【 摘 要 】

InvestigationsofLowerandMiddleOrdovicianbrachiopodsinnortheasternSpitsbergenhaverevealedstrongtiestofaunasinNorthAmericaandGreenlandatthegenericlevel,althoughthefaunaappearsmostlyendemicatthespecieslevel.DuringtheearlyPalaeozoic,thearchipelagoofSvalbard,includingSpitsbergen,waslocatedatequatoriallatitudesalongthenortheasternmarginofLaurentia.ThenortheasternpartofSpitsbergenexperiencedsignificantsealevelchanges,changingfromveryshallowwaterintheTremadociantodeepwaterintheFloianandslowlybacktoshallow-watercarbonateenvironmentsintheMiddleOrdovician.TheTremadocianandearlyFloianbrachiopodfaunawasoflowdiversitywithahighproportionofcosmopolitanwarm-waterrelatedrhynchonelliformgenera.InthelateFloiantherewasanabruptdiversificationevent,takingplaceagainstthebackgroundoftheincreasingisolationofLaurentia,leadingtoadiverse,mostlyendemicfauna.ThisdiversefaunaremainedintotheMiddleOrdovician.AsimilardiversificationeventhasbeenrecordedinNorthAmerica,buthereitoccurslater,intheDapingian.ThediachroneityofbrachiopoddiversificationwithindifferentpartsofacontinenthaspreviouslybeenshownforSouthChina,suggestingthatitmaybeacommonphenomenon.IncontrasttothemostlyendemicMiddleOrdovicianrhynchonelliformgenera,thelinguliformbrachiopodsincludedmanygenerawithawidedistribution.Thisdifferenceisattributedtotheirdifferentdispersalstrategies.

【 授权许可】

Unknown