The oldest known European Neogene girdled lizard fauna (Squamata, Cordylidae), with comments on Early Miocene immigration of African taxa

摘要

ThispaperreportsonthefirstrecordofcordylidlizardsfromthelocalityofMerkur-North.ThefossilhistoryofgirdledlizardsisverypoorlyknownandthisgroupwasrareduringtheLowerMioceneinEurope.Thefossilsdescribedhereincomefromgreycalcareousmarlsatthebaseoftheso-called“MainBrownCoalSeam”.ThesemarlsareinterpretedasreworkedvolcanicashandthesedimentsareconsideredasearlyMioceneinageandarepreciselyequatedwiththeMN3azone.Forthisreason,thecordylidfaunafromthislocalityisolderthanpreviouslydescribedMiocenematerialanditrepresentstheoldestknownNeogenecordylidsinEurope.ThematerialofthedentaryisverysimilartothatofPalaeocordylusbohemicusRo?ek,1984,describedfromtheyoungerlocalityofDolnicenearCheb.Theintramandibularseptumofthedentarydescribedherein,lyingventromediallyfromthealveolarcanal,hasafreeposterolateralportion.Itrepresentsthefirstreportofthisstructureincordylids.Themaxillaisonlyfragmentarilypreserved.Thesizedifferencebetweenthemaxillaryanddentaryelements,thenumberofteethand,especiallytheirmorphologyevokesthepossibilityoftwodifferenttaxa.Unfortunately,itisimpossibletodecideonthebasisofsuchlimitedmaterialifbothfindsrepresentindependentformsoronlyextremeformsofthesametaxon.