DEVONIAN RUGOSE CORALS FROM ZHAOTONG,NE YUNNAN(1)——SOME EMSIAN AND EIFELIAN RUGOSE CORALS
【Abstract in Chinese】 云南省昭通市东北郊箐门出露了一条比较完整的泥盆纪浅海相地层剖面,下、中、上三个统均有出露,浅海底栖生物化石丰富,研究基础也相对较好,是研究滇东北地区泥盆纪地层的一条理想剖面。由于地层剖面比较长,沉积厚度比较大,文中仅描述该剖面早泥盆世和中泥盆世早期的四射珊瑚,并讨论有关地层划分和珊瑚群古生物地理亲缘关系。
【Abstract】 The rugose corals described in the present paper were collected by one of the authors(Liao Weihua)from the Qingmen section of Zhaotong,NE Yunnan in 1972.These corals,occuring in association with brachiopods(Rostrospirifer ardenensis,Rostrospirifer tonkinensis,Acrospirifer orthogonalis, Acrospirifer lungmenshanensis, Atrypa sp.,Cyrtina sp.,"Delthyris"sp.,Dicoelostrophia beblistriata,Dicoelostrophia punctata,Elyta sp., Eosophragmophora sp., Howittia sp.,Howellellasp.,Kwangsiacf.yohi,Mesodouvillina orientalis,Nadiastrophia pattei,Parachonetes nasutus,Parathyrisina tangnae,Schuchertellasp.),Stromatoporoids(Clathrodictyon sp.,Anostylostromasp.,Atelodictyonsp.,Ferestrom-atopora sp.),and bivalves(Leptodesma ?sp.,Mytilarea sp.),were found in a series of sandstones,mudstones intercalated with marls or argillaceous limestones.The rugose corals described and illustrated comprise 11 species within 8genera.They include two rugose coral Assemblages in ascending order:The first rugose coral Assemblage(Early Devonian Emsian):Acanthophyllumcf.guitangense Yu et Liao Australophyllum cyathophylloides Hill Calceola intermediata intermediata Yoh Calceola sandalina nanningensis Yoh Cystiphylloides cf.fongi(Yoh)Cystiphylloides mirabile Wedekind et Vollbrecht Edaphophyllum zhaotongense sp.nov.Tryplasmacf.guangxiensis Yu et LiaoXystriphyllumcf.devonicum Bulvanker The second rugose coral Assemblage(Middle Devonian Eifelian):Utaratuia yunnanensis sp.nov.Xystriphyllum hyperbolicum Crickmay Among the first rugose coral Assemblage,Acanthophyllum cf.guitangense and Tryplasma cf.guangxiensis have been recorded from the Lower Devonian(Emsian)Guitang Formation of Guangxi,Calceola intermediata intermediata and Calceola sandalina nanningensis have hitherto been known from the Lower Devonian(lower Emsian) Yukiang Formation of Guangxi and the Pochiao Formation of SE Yunnan respectively.Australophyllum cyathophylloides, Cystiphylloides mirabile and Xystriphyllum devonicum were reported from the Lower Devonian of Queensland(Australia)and Kuznetsk basin(Russia)respectively.The coexistent brachiopods Mesodouvillina orientalis, Parachonetes nasutus,Eosophragmophora sp.,Rostrospirifer ardenensis, Rostrospirifer tonkinensis, Nadiastrophia pattei,Parathyrisina tangnae,Dicoelostrophia beblistriata,Dicoelostrophia punctata,and Howellella sp.which all are the characteristic lower Emsian brachiopods of the Yukiang Formation in Guangxi as well as of the Pochiao Formation in SE Yunnan.In the second rugose coral Assemblage,Xystriphyllum hyperbolicum has been found from the Hume Formation(Eifelian)of the Northwest Territories of Canada and Utaratuiais also a common genus in the early Middle Devonian(Eifelian)of Guangxi, Guizhou and Sichuan,South China.Some associated brachiopods:Kwangsiacf.yohi,Nadiastrophiasp.,Acrospirifer orthogonalis and Acrospirifer lungmenshanensis are the common fossils for the Longdongshui Formation of Guizhou and the Yingtang Formation of Guangxi.Taken as a whole,the first coral Assemblage indicates an Early Devonian(early Emsian)age,obviously bearing a much closer relationship with those of Guangxi,SE Yunnan,as well as the Russia and Australia.The second coral Assemblageappears a Middle Devonian(Eifelian)age,showing a high level of similarity with that of Guangxi,Guizhou and the northwest Territories of Canada.Although the coral material derived from there is rather meagre,a few genera and species,however,afford evidence of considerable weight for the determination of the age of the strata.Since the Devonian rugose corals have not yet been reported in NE Yunnan,a brief description of these fossils seems desirable.
【Key words】 Rugose corals； Emsian； Eifelian； Zhaotong； northeastern Yunnan；
- 【Source】 古生物学报 ,Acta Palaeontologica Sinica , Editorial E-mail ,2016(03)
- 【CLC code】Q915