简介:NewObservationsonphosphatizedSpheroidalFossilsinSinianDoushantuoanPhosphoritesinWeng'an,GuizhouProvinceInrecentyearsmuchattentionhasbeenpaidtophosphatizedspheroidalfossilsfoundintheSinianDoushantuoanphosphoritesinweng'an,GuizhouProvince.Disputeshavebeenlongexistedabouttheirphylogeneticaffinity.Basedonsomenewdiscoveriesandthepresentknowledge,someresearchersinterpretsomeofthephosphatizedspheroidalfossilsasanimalembryos,whereasothersholodtheutterlyidifferentviewthattheypaper,basedonnewdataofsomespheriodalfossilsindiscussedandreinterpreted.Itisobviousthatthephosphatizedspheroidalfossilassemblagefoundinweng'anconsistsofcyanobacteria,benthicmelticellularalgae,planktonicacritarchsandotherfossilswithuncertainassignments,andprovideanexceptionallywell-preservedphosphatizedLagerstatten.
简介:OurfieldworkandgeochronologicstudiesinnorthernHebeiandwesternLiaoningareasindicatethatthemajorMesozoiccontractionaleventsintheYanshanbeltareof(1)pre-MiddleJurassic(Indosinian?),(2)LateJurassicand(3)EarlyCretaceousage.ThefirstN-SshorteningcouldbeaconsequenceofthecollisionoftheMongolianarcsalongtheSolonsutureagainsttheNorthChinaplate.Siberian-NorthChinaplatecolli-