Brachiopod Gyrosoria Cooper, 1973 – a comparative palaeoecological, stratigraphical and taxonomical study

Bulletin of geosciences

Simon E¹  Sklenář J¹ 

关键词: Brachiopoda;    Cancellothyridoidea;    Upper Cretaceous;    environmental adaptation;    palaeoecology;    shell structure;    biostratigraphy;   

DOI  :  

来源: Czech Geological Survey

【 摘 要 】

Cooper(1973)erectedGyrosoriaasamonospecificgenusforTerebratulitesgracilisvonSchlotheim,1813.G.gracilisfromwhite-chalkfacieswasstudiedindetailbySteinich(1965)anditsmorphologicaladaptationtotheenvironmentwasdiscussedbySurlyk(1972).However,populationsofG.gracilis,adaptedtoahighenergyenvironmentremainedunnoticedandthereforespecialattentionispaidtotheminthispaper."Terebratulina"lataEtheridge,1881,placedhereinthegenusGyrosoria,hasoftenbeenmentionedwithintheliteratureandhasbeenusedasazonefossilformorethanacentury.However,itsmorphologyanditsrelationtootherreportedcancellothyrididspecieshasnotbeenstudiedindetailsinceitserection.Thispaperpresentsanemendeddiagnosisofthegenus,officiallyassignstherevisedlataspeciestoitandpresentsadetailedmorphologicalstudyofthegenus.ThevariabilityofG.lata,studiedhere,andcomparedtothatofboth,thelow-andhigh-energy-environmentformsofG.gracilis,pointsoutaclearevolutionarylineagewithinthegenus.SpicularskeletonshavebeeninvestigatedinsomeUpperTuronianG.latashells.Particularattentionisgiventotheshellinfrastructure.MoreoverthispapershowsthatthepalaeogeographicalareaofG.latacannowbeenlargedbutawiderapplicationofthisspeciesinbiostratigraphyshouldberefusedduetotheextensionofitsstratigraphicalrange.

【 授权许可】

Unknown