新疆西准噶尔地区泥盆-石炭系界线附近的石燕贝类腕足动物

SPIRIFERIDE AND SPIRIFERINIDE BRACHIOPODS ACROSS THE DEVONIAN AND CARBONIFEROUS BOUNDARY IN WESTERN JUNGGAR, XINJIANG

系统描述采自新疆和布克赛尔蒙古自治县和什托洛盖镇附近上泥盆统—下石炭统的3个剖面(布龙果尔剖面、布克河剖面和俄姆哈剖面)上的石燕贝类,总计6属7种:Austrospirifer?sp.,Spirifer ga peevi Simorin,Unispirifer persianum Brice,Syringothyris texti formis F M Zhang,Syringothyris hannibalensis(Swallow),Histosyrinx sp.及Tylothyris sp.,其中,Austrospirifer?sp.,Syringothyris hannibalensis(Swallow)及Histosyrinx sp.产自法门阶上部;其余属种产自上泥盆统—下石炭统。S.textiformis及S.hannibalensis的腹壳内部结构以具有发育的管孔及缺失中隔板为主要特征,不同的是前者腹壳后部次生加厚强烈、管孔长度较大。文中早石炭世的腕足类数量相对较少,难以对泥盆-石炭纪界限上下的石燕贝类面貌进行比较,暂将西准噶尔地区晚泥盆世—早石炭世的石燕贝类(不含弓石燕类)的腕足动物一并称为Syringothyris-Spirifer动物群,在组成上与哈萨克斯坦、俄罗斯库兹涅茨盆地、莫斯科盆地及北美同期的化石组合较为相似,与华南有较大差异。

Six genera and seven species of spiriferide and spiriferinide brachiopods are described from three upper Devonian-lower Carboniferous boundary sections （Bulongguoer, Hebukehe, and Emuha）, near Hoxtolgay Town, Hoboksar County, Xinjiang. These brachiopod species are Austro- spirifer？ sp. , Spirifer gapeevi Simorin, Unispiri fer persianum Brice, Syringothyris texti formis F M Zhang, Syringothyris hannibalensis （Swallow）, Histosyrinx sp. and Tylothyris sp. Amongst them, Austrospirifer？ sp. , Syringothy- ris hannibalensis （Swallow） and Histosyrinx sp. were discovered from the upper part of the Famennian, whilst the others were colleted from Late Devonian Famennian to Early Carboniferous strata. The ventral internal structures of both Syringo-thyris textiforrnis F M Zhang and Syringothyris hannibalensis （Swallow） are mainly characterized by having a well-developed syrinx and lacking a median septum, but the former species possesses a distinctly thickened ventral posterior （callus deposits） and a much longer syrinx. Early Carboni- ferous Tournaisian brachiopod specimens （especially spiriferide and spiriferinide taxa） in this study are relatively rare compared with those of the latest Famennian, which makes a meaningful comparison of brachiopod faunas impossible. The Late Devonian-Early Carboniferous spiriferide and spiriferinide brachiopods of western Junggar, which can tentatively be named the Syringothyris- Spirifer assemblage, are similar to contemporaneous assemblages of Kazakstan, Kuznetsk Basin, Moscow Basin and North America, and are distinctively different from those of South China.