《New specimens of Stenocybus acidentatus （Therapsida： Dinocephalia） from the Middle Permian Dashankou Fauna of China》.pdf

Vo1．88No．3PP．730～737 ACTAGEOLOGICASINICA(EnglishEdition) June2014 NewspecimensofStenocybusacidentatus(Therapsida：Dinocephalia) from theM iddlePermianDashankouFaunaofChina JIANG Shan andJIShu．an InstituteofGeology,ChineseAcademyofGeologicalSciences,KeyLaboratoryofStratigraphyand Paleontology,MinistryofLandandResources；Beijing100037,China Abstract：ThebasaldinOcephalian cladeStenocybusidaewasknownfrom twoincompletespecimens representingonegenerus，Stenocybus。rfom DashankoufanuainYumen，GansuProvineeofChina．The holotypeofStenocybusacidentatusislaterally compressed．ma~ngsomecharactersunclear．Herewe describewt onew specimensofStenocybusacidentatusrfom thesamelocality,ananteriorportionofskull witharticulatediaws，andarightdentarywithnearlycompletedentiti0n．Theyshow somedetailed featureson the morphology ofthe premaxilla，maxma，nasal，externalnares and dentary．The phylogenetic relationship bewt een Stenocybus acidentatus and the relatively large Sinophoneus yumenensisisstilldiffi culttodetermine，andneedsmorenew completematerialandfurtherevidences． Keywords：Dinocephalia，stenOcybusidae，DashankouFauna，M iddlePermian 1IntrOductiOn Souht Arficasincethemiddlenineteenht century．They fomr edpartoftheearliesttherapsidfaunaoftheRussian The Dashankou therapsid fauna was originally Ocherand Isheevo fomr ationsfHopson andBraghusen． discoveredbyProf．ChengZhengwu in 1981from the 1986；Olson．1986；Sennikov．1996；Battailna dSurkovet southwestto the old town of men City ofGansu a1．，2000；Golubev,2000；Modestona dRybczynski。2000； Province，northwestem China (Fig．11．Thisfauna is SennikovandGolubev,2012)，andtheywerealsopresent featured by anthracosaur amphibians na d therapsid asna impor