The fossil record of Antarctic land mammals:commented review and hypotheses for future research

作者：Javier NGELFO,Francisco JGOIN,Nicolás BAUZá,Marcelo REGUERO

摘要：The fossil record of terrestrial mammals in Antarctica is temporally and geographically constrained to the Eocene outcrops of La Meseta and Submeseta formations in Seymour(Marambio)Island in West Antarctica.The faunal assemblage indicates a clear South American imprint since all the groups have a close phylogenetic relationship with Cretaceous and Paleogene mammals from Patagonia.Despite the presence of several mammalian taxonomic groups:Dryolestida,Gondwanatheria,Eutheria and Metatheria,the presence of other major mammalian taxa should be expected and will probably be confirmed by new findings.Placental mammals with an inferred body mass between 10 to 400 kg in size,are represented by xenarthrans,and two groups of the so called South American native ungulates:Astrapotheria and Litopterna.The Metatheria are the smaller(less than 1 kg)and most abundant components of the fauna.Marsupials are represented by derorhynchid ameridelphians,several microbiotherian australidelphians(both microbiotheriids and woodburnodontids),and?glasbiid prepidolopod and polydolopid polydolopimorphians.Plus,there are remains of several mammalian teeth of indeterminate phylogenetic affinities.The present knowledge of the Southern Hemisphere mammalian evolution and paleogeographic change through time,indicates that Antarctica played a major role for land mammals,at least since the Jurassic.The actual representation of Paleogene terrestrial mammals in Antarctica is most probably biased,as all the evidence indicates that australosphenidan mammals should be present in this continent since the Jurassic.

发文机构：Consejo Nacional de Investigaciones Científicas y Técnicas（CONICET） División Paleontología Vertebrados Facultad de Ciencias Naturales y Museo de La Plata MORPHOS Lab Instituto Antártico Argentino

关键词：AntarcticaJamesROSSBasinJurassicPALEOGENEEOCENEMAMMALIA

分类号： P53[天文地球—古生物学与地层学][天文地球—地质学]