Mammaliaforms are extinct and extant organisms that are closely related to mammals.Studying mammaliaforms helps scientists understand the evolutionary processes that led to various mammalian features.In two consecutiv...Mammaliaforms are extinct and extant organisms that are closely related to mammals.Studying mammaliaforms helps scientists understand the evolutionary processes that led to various mammalian features.In two consecutive studies in Nature,Dr.MAO Fangyuan and Dr.ZHANG Chi from the Institute of Vertebrate Paleontology and Paleoanthropology(IVPP)of the Chinese Academy of Sciences(CAS),together with colleagues from Australia and the United States.展开更多
The materials of Tapirus from Renzidong, Fanchang, Anhui Province, are the best ones among the early most Pleistocene findings in China up to now, not only in richness, but also in completeness. The fossils contain co...The materials of Tapirus from Renzidong, Fanchang, Anhui Province, are the best ones among the early most Pleistocene findings in China up to now, not only in richness, but also in completeness. The fossils contain complete tooth rows of both the upper and the lower, as well as most parts of the postcranial skeletons. These materials are very helpful in understanding the evolutionary level of this kind of animal. In morphology, the materials from Fanchang appear to be very similar to Tapirus sanyuanensis, and can be placed within this species. The materials from Fanchang provided sound evidence to distinguish the Early Pleistocene tapirs and the living form Tapirus indicus, As to the geological distribution, it can be tentatively concluded that Tapirus sanyuanensis and Tapirus sinensis only appeared in Early Pleistocene, Megatapirus appeared after Early Pleistocene, and lasted until Holocene. The Early Pleistocene tapirs of South China resemble Megatapirus more closely than Tapirus indicus.展开更多
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...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.展开更多
文摘Mammaliaforms are extinct and extant organisms that are closely related to mammals.Studying mammaliaforms helps scientists understand the evolutionary processes that led to various mammalian features.In two consecutive studies in Nature,Dr.MAO Fangyuan and Dr.ZHANG Chi from the Institute of Vertebrate Paleontology and Paleoanthropology(IVPP)of the Chinese Academy of Sciences(CAS),together with colleagues from Australia and the United States.
基金This work was supported by the National Climbing Project (Grant No. PD98001).
文摘The materials of Tapirus from Renzidong, Fanchang, Anhui Province, are the best ones among the early most Pleistocene findings in China up to now, not only in richness, but also in completeness. The fossils contain complete tooth rows of both the upper and the lower, as well as most parts of the postcranial skeletons. These materials are very helpful in understanding the evolutionary level of this kind of animal. In morphology, the materials from Fanchang appear to be very similar to Tapirus sanyuanensis, and can be placed within this species. The materials from Fanchang provided sound evidence to distinguish the Early Pleistocene tapirs and the living form Tapirus indicus, As to the geological distribution, it can be tentatively concluded that Tapirus sanyuanensis and Tapirus sinensis only appeared in Early Pleistocene, Megatapirus appeared after Early Pleistocene, and lasted until Holocene. The Early Pleistocene tapirs of South China resemble Megatapirus more closely than Tapirus indicus.
基金supported by Instituto Antártico Argentino–Dirección Nacional del Antártico (IAA–DNA)the funding PIP 0489 and N812-UNLP Vertebrados del lapso Cretácico Superior Paleógeno de la Península Antártica y extremo sur de Patagonia (Sur del Paralelo 50°)
文摘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.
