新疆吐鲁番盆地桃树园晚二叠世非海相腹足类_朱祥根.pdf

收稿日期:2021-12-14;改回日期:2022-06-27;录用日期:2022-07-02*现代古生物学和地层学国家重点实验室基础性研究专项(20102106)资助。*通讯作者:朱祥根,研究员,e-mail: 古生物学报,61(4):628642(2022年12月)Acta Palaeontologica Sinica,61(4):628642(December 2022)研究论文 DOI:10.19800/ki.aps.2021072 新疆吐鲁番盆地桃树园晚二叠世非海相腹足类*朱祥根*中国科学院南京地质古生物研究所,南京 210008 提要 新疆吐鲁番盆地桃树园地区晚二叠世地层称作下仓房沟群,自下而上分为泉子街组、梧桐沟组和锅底坑组,为河湖相碎屑沉积,剖面连续,层序清楚,动、植物化石丰富。文中研究的腹足类标本产于桃东沟剖面梧桐沟组下部和中部的介壳灰岩层和灰岩透镜体中,见有2层,计有2科4属6种:Xinjiangospira rotundata Yu et Zhu,Xinjiangospira habita sp.nov.、Hydrobia turpanensis Wei、Hydrobia orientalis sp.nov.、Pseudamnicola tao-donggouensis sp.nov.和Valvata complanusa sp.nov.;与腹足类共生的有双壳类、叶肢介、介形类,以及植物和脊椎动物化石等,其中双壳类主要是Palaeanodonta,Palaeomutela和Anthraconauta 等属。该腹足动物群由Hydrobiidae 和 Valvatidae的属种组成,标本数量多,壳体小,保存完好,是迄今已知属种最丰富的古生代淡水腹足类动物群。当前梧桐沟组腹足动物群面貌与准噶尔盆地大龙口剖面小龙口组(锅底坑组),以及非洲罗得西亚南部上二叠统卡鲁系的腹足动物群面貌一致。关键词 非海相腹足类 梧桐沟组 晚二叠世 桃东沟剖面 吐鲁番盆地 中文引用 朱祥根,2022.新疆吐鲁番盆地桃树园晚二叠世非海相腹足类.古生物学报,61(4):628642.DOI:10.19800/ki.aps.2021072 英文引用 Zhu Xiang-gen,2022.Late Permian non-marine gastropods from Taoshuyuan,Turpan Basin,Xinjiang.Acta Palaeontologica Sinica,61(4):628642.DOI:10.19800/ki.aps.2021072 Late Permian non-marine gastropods from Taoshuyuan,Turpan Basin,Xinjiang ZHU Xiang-gen Nanjing Institute of Geology and Palaeontology,Chinese Academy of Sciences,Nanjing 210008,China Abstract The Late Permian Xiacangfanggou Group in Taoshuyuan area of Turpan Basin,Xinjiang consists of the Quanzijie,Wutonggou and Guodikeng formations in ascending order.The sedimentary sequence represents continuous fluvial-lacustrine siliciclastic deposits with abundant animal and plant fossils.The gastropod specimens described in this paper are found from the bioclastic limestone layers and limestone concretions in the lower and middle parts of the Wutonggou Formation at the Taodonggou section.These gastropod fossils collected from two horizons are assigned to six species,four genera belonging to two families.These species are Xinjiangospira rotundata,Xinjiangospira habita sp.nov.,Hydrobia turpanensis,Hydrobia orientalis sp.nov.,Pseudamnicola taodonggouensis sp.nov.and Valvata com-planusa sp.nov.Other associated fossils are bivalves,phyllopods,ostracods,vertebrates and plants.The bivalves are domi-nated by Palaeanodonta,Palaeomutela and Anthraconauta.The Late Permian gastropod fauna from the Wutonggou For-mation is composed of freshwater Hydrobiidae and Valvatidae.Characterized by well-preserved speci mens 4 期 朱祥根:新疆吐鲁番盆地桃树园晚二叠世非海相腹足类;Zhu:Late Permian non-marine gastropods from Xinjiang 629 in large quantity,this fauna represents the most abundant Paleozoic freshwater gastropod fauna known so far.This fauna shows similarity to those from the Xiaolongkou Formation(=Guodikeng Formation)from the Dalongkou sec-tion,Junggar Basin,and the Upper Permian(Karu System)in southern Rhodesia,Africa.Key words non-marine gastropods,Wutonggou Formation,Late Permian,Taodonggou section,Turpan Basin SYSTEMATIC PALEONTOLOGY Subclass Caenogastropoda Cox,1960 Order Littorinimorpha Golikov et Starobogatov,1975 Superfamily Truncatelloidea Gray,1840 Family Hydrobiidae Stimpson,1865 Genus Xinjiangospira Yu et Zhu,1990 Type species Xinjiangospira rotundata Yu et Zhu,1990 Diagnosis Shell small,conical or long conical with 47 whorls,apex blunt and protoconch submerged or abnormally rotating.Whorl convex,fast growing,sutures deep,and slightly oblique.Aperture large,nearly round or ovoid.Shell surface with slightly curved growth lines.Xinjiangospira habita sp.nov.urn:lsid:zoobank.org:act:C609561C-33DA-44EB-834B-A9B5200DAC30(Fig.3)Etymology The species name is derived from the Latin habitus,meaning plump.Material Six well-preserved specimens;depos-ited in the Nanjing Institute of Geology and Palaeontol-ogy,Chinese Academy of Sciences.Cat.No.:NIGP 175963175968.Holotype NIGP 175965.Paratypes NIGP 175963175964,175966175 968.Measurements NIGP 175965(Holotype):H:4.2 mm,D:2.4 mm,h:1.2 mm,d:1.2 mm.Diagnosis Shell small,cone wide,with 45 whorls.Apex blunt and protoconch slightly submerged.Whorl round convex,suture deep and slightly inclined.Last whorl high,protruding significantly.Aperture round or oval,peristome continuous.Umbilicus narrow and shallow.Shell surface with fine growth lines.Description Shell small,cone wide,with 45 whorls.Shell height greater than shell width,apex blunt and protoconch slightly submerged.First whorl small,horizontal rotation;second whorl more regular;third whorl growth rapid and its height approximately equal to the height of the front two whorls.Last whorl high and large,convex swelling significantly;its height accounting for about two thirds of the shell height.Whorl round con-vex,suture deep and slightly inclined.Shell surface with fine growth lines.Aperture round or oval,peristome con-tinuous,parietal lip appressed to the lower part of the last whorl.Height of aperture about one half of the height of last whorl.Umbilicus narrow and shallow.Remarks The new species is similar to Xin-jiangospira rotundata Yu et Zhu,1990 in shell shape and apex.The main difference is that the aperture of the new species is round or oval,and the peristome is continuous.Genus Hydrobia Hartmann,1821 Type species Cyclostoma acutum Draparnaud,1805 Diagnosis Shell small,low conical to tower shaped.Whorl convex.Shell surface smooth or with growth lines.Aperture oval or elliptic.Peristome con-tinuous,generally without umbilicus.Hydrobia orientalis sp.nov.urn:lsid:zoobank.org:act:D30B67DA-7458-4038-9106-F3E92F7DDC05(Fig.5)Etymology The species name is derived from the Latin orientalis,meaning oriental.Material Eight well-preserved specimens;depos-ited in the Nanjing Institute of Geology and Palaeontol-ogy,Chinese Academy of Sciences.Cat.No.:NIGP 175979175986.Holotype NIGP 175979.Paratypes NIGP 175980175986.Measurements NIGP 175979(Holotype):H:4 mm,D:1.8 mm,h:1.6 mm,d:1.2 mm.Diagnosis Shell small,highly conical,apex acute.Shell with five whorls,regular growth in early ones.Whorls roundly convex.Last whorl increasing rapidly and bulging significantly.Suture deep and inclined.Ap-erture semilunar or narrowly ovate,no umbilicus.Description Shell small,high conical,apex acute.Shell with five whorls,regular growth in early ones.Whorl round convex.Last whorl increasing rapid-ly and bulging significantly,and its height accounting for about half of the shell height.Suture deep and in-clined.Shell surface smooth with only fine growth lines.Aperture semilunar or narrowly ovate,upper end angu-lar,and front end slightly narrowed.No umbilicus.Remarks The new species differs from Hydrobia turrpanensis Wei,1984 in having smaller,high conical shell with inclined suture,and semilunar aperture with-out umbilicus.The new species also differs from Hy-drobia gandwanica Cox,1953 from the Upper Permian Karoo System of southern Africa in that the latter has larger shells,higher spire head,and less obvious inclina-tion of suture.630 古 生 物 学 报 61 卷 Genus Pseudamnicola Paulucei,1878 Type species Pseudamnicola lucensis Issel,1866 Diagnosis Shell small to very small,ovoid,with 45 whorls.Spiral low.Last whorl high,width increases significantly.Base flat,with umbilicus.Aperture high,round to oval,with continuous mouth margin.Pseudamnicola taodonggouensis sp.nov.urn:lsid:zoobank.org:act:72256B65-A194-4581-A5CB-B2E38BB7CB86(Fig.6)Etymology Named after the Taodonggou section,referring to the location where the specimen was found.Material Seven well-preserved specimens;de-posited in the Nanjing Institute of Geology and Palae-ontology,Chinese Academy of Sciences.Cat.No.:NIGP 175987175993.Holotype NIGP 175988.Paratypes NIGP 175987,175989175993.Measurements NIGP 175988(Holotype):H:2.5 mm,D:2.0 mm,h:1.5 mm,d:1.0 mm.Diagnosis Shell very small,conical,with four whorls.Spire low,whorls growing regularly.Last whorl increasing rapidly,base flat,with umbilicus.Aperture high and oval.Description Shell very small,conical,with four rounded whorls and obtusely rounded apex.Spire low conical,occupying about one-third of shell height;spire whorls increasing regularly,with obvious shoulder;su-ture deep.Last whorl increasing rapidly,occupying ap-proximately two-thirds of the shell height,and obviously inflated.Periphery round and convex,in the lower part of the whorls.Base flat,with umbilicus.Aperture high,ovoid,upper end narrow rounded,lower end wide cir-cular.Shell smooth,with faint fine growth lines.Remarks The new species is similar to Pseud-amnicola acuta Pan,1982 from the Middle Jurassic Qiketai Formation in the Turpan Basin of Xinjiang and the Middle Jurassic Toutunhe Formation in the Junggar Basin(Guo et al.,1982;Zhu,1994;Pan and Zhu,2012),but they differ in that the shell of the Pseudamnicola acuta is long ovate with acute apex,and the periphery is located in the middle of the whorl.Subclass Heterobranchia Burmeister,1837 Superfamily Valvatoidea Gray,1840 Family Valvatidae Gray,1840 Genus Valvata Mller,1774 Type species Valvata cristata Mller,1774 Diagnosis Shell discoid or wide conical;whorl circle.Suture deep,aperture round.Umbilicus wide and deep.Valvata complanusa sp.nov.urn:lsid:zoobank.org:act:059B0E45-CD8E-41AE-99CC-34C228538D8F(Fig.7)Etymology The species name is derived from the Latin complanus,meaning flat.Material Seven well-preserved specimens;de-posited in the Nanjing Institute of Geology and Palae-ontology,Chinese Academy of Sciences.Cat.No.:NIGP 175996176002.Holotype NIGP 175996.Paratypes NIGP 175997176002.Measurements NIGP 175996(Holotype):H:1.0 mm,D:1.1 mm,h:0.5 mm,d:0.5 mm.Diagnosis Shell very small,high discoid.Shell width slightly greater than height.Apex flat.Whorls convex,increasing regularly,aperture large,perfectly round,occupying about one half of shell height.Suture medium deep.Shell surface with growth lines.Umbili-cus narrow and shallow,accounting for about one-fourth of shell width.Description Shell very small,high discoid,with 2.53 whorls.Shell width slightly greater than height.Spire low and apex flat.Whorls convex and increasing regularly;first whorl small and flat;second whorl be-ginning to spin down gradually at the end and winding under the periphery of first whorl.Growth of last whorl not obvious.Aperture large and perfectly round,occu-pying about one half of shell height.Suture medium deep.Shell surface with growth lines.Umbilicus narrow and shallow,accounting for about one-fourth of shell width.Remarks The first whorl of the new species is small and planispiral,which is similar to that of Valvata helicoides(Forbes)from the Middle Jurassic Qiketai Formation in Shanshan County,Turpan Basin(Zhu,1994).They differ in that the size of Valvata helicoides(Forbes)is four times larger,its last whorl grows rapid-ly,and its shell is nearly twice as wide as its height.1 前 言 古生代非海相腹足类很少,其中淡水腹足类更为罕见,目前资料确切的记载仅见于欧洲、非洲南部罗得西亚(Rhodesia),以及中国新疆等几个地点,均属于Viviparidae、Hydrobiidae和Pleuroceridae科,属种单调,标本稀少。1922年,Garwood依据英格兰约克郡(Yorkshire)里布尔斯代尔(Ribblesdale)地区早石炭世地层中的腹足类,描述报道了新种Viviparus carbonarius,标本仅为内核,壳体高14.0 mm,末螺环高6.5 mm。Garwood(1922)将其归入Viviparidae科,当时被认为是最古老 4 期 朱祥根:新疆吐鲁番盆地桃树园晚二叠世非海相腹足类;Zhu:Late Permian non-marine gastropods from Xinjiang 631 的淡水腹足类的记录。1927年,Cox依据1915年格林威治医院(Greenwich Hospital)塞勒梅斯顿庄园(Seremerston)钻孔(1号)岩芯中发现的腹足类,描述报道了新属新种Bernicia prae-cursor。该钻孔岩芯为早石炭世晚期煤系地层,腹足类产于煤系地层夹持的深灰色淡水石灰岩中。Ber-nicia praecursor个体很小,壳高3.0 mm,壳宽2.5 mm,末螺环高2.6 mm,壳口高1.8 mm,壳口宽1.4 mm,壳体已黄铁矿化,表面纹饰保存完好,与其共生的有同样黄铁矿化的昆虫和植物印痕。Cox(1927)将Bernicia属归置于Hydrobiidae科,同时认为Garwood于1922年建立的Viviparus carbonarius种名已有使用,故将其更改为Viviparus garwoodi(Garwood)。1949年,Yen依据苏格兰特维查尔附近的威姆格伦(Wham Glen,Twechar)早石炭世晚期Namurian A顶部灰岩下方页岩中的腹足类,描述报道新属新种Carbonispira scotica。该种为单一标本,壳体约有8个螺环组成,壳高13.5 mm,末螺环宽6.4 mm,Yen将Carbonispira属归置于Pleuroceridae科(Yen,1949)。1953年,Cox根据非洲罗得西亚(Rhodesia)南部上二叠统卡鲁系(Karroo System)Madumabisa页岩层的腹足类,描述报道新种Hydrobia gandwanica。该种壳体由6个螺环组成,壳高7.2 mm,壳宽2.7 mm,壳面生长线清晰。与其共生的有淡水双壳类、介形类,以及植物、鱼类、爬行类等,Cox将Hydrobia 属归置于Hydrobiidae科(Cox,1953)。1990年,余汶等首次描述报道了中国古生代淡水腹足类(余汶、朱祥根,1990),标本产于新疆吉木萨尔大龙口剖面晚二叠世小龙口组(=锅底坑组,下同),共记述Xijiangespira rotundata,X.cf.gondwani-ca,Bernicia?jimsarensis 2属3种,其中Xijiangespira rotundata为新属新种,Bernicia?jimsarensis为新种,当时均被归置于Hydrobiidae科。小龙口组腹足类的个体都很小,Xijiangespira属的壳体高度一般在3.0 mm左右,壳宽约2.0 mm;与其共生化石有双壳类、介形类、叶肢介,以及植物、鱼类、爬行类等。俄罗斯上二叠统鞑靼阶也曾有腹足类的报道(Revunova,1938),但对标本所在地层以及标本修理和系统分类等方面均存在疑问,许多腹足类研究者对此都有详细的评述(Yen,1949;Cox,1953;Solem and Yochelson,1979),本文不再赘述。除此之外,有资料提及欧美地区晚古生代地层中还发现田螺类(Viviparus)和盘螺类(Valvata)等少量淡水腹足类(Cox,1927;Yen,1949;Solem and Yochelson,1979),但均未见正式的描述报道。对古生代非海相腹足类,一些学者都在论著中进行过回顾和总结,他们除对北美古生代陆栖肺螺类做了详细论述外,也对其他地区古生代非海相腹足类进行了讨论。1960年,Moore在编撰Treatise on Invertebrate Paleontology时,也对上述早期报道的古生代淡水腹足类进行了评述与厘定,指出Garwood(1922)建立的时代为早石炭世的Viviparus garwoodi(=Viviparus carbonarius)是内核标本,具有较多的不确定性(Moore,1960,p.318);Cox(1927)建立的时代为早石炭世晚期的Bernicia praecursor也存有疑问,并将其从原来的Hydrobiidae科转移至Viviparidae科(Moore,1960,p.319);Yen(1949)建立的时代为早石炭世晚期的Carbonispira scotica所依据的标本保存不好,描述的特征可能是由于压碎和腐蚀所致,因此对此 属 持 有 疑 问,并 将 其 转 移 至 Cyclophoridae 科(Moore,1960,p.318);Cox(1953)建立的时代为晚二叠世的Hydrobia gandwanica 未有评述,仍将其归置于Hydrobiidae科。由此可见,在中国新疆准噶尔盆地晚二叠世小龙口组淡水腹足类报道(余汶、朱祥根,1990)之前,非洲罗得西亚南部晚二叠世卡鲁系(Karroo System)的Hydrobia gandwanica是全球唯一无疑义的古生代淡水腹足类。本文对吐鲁番盆地晚二叠世梧桐沟组淡水腹足类的报道,不仅丰富了全球晚二叠世淡水腹足动物群的内容,也为古生代淡水腹足动物的分布及起源演化研究提供重要资料。2 地层剖面与化石材料 新疆吐鲁番盆地桃树园剖面位于吐鲁番火车站东北约20 km处,以桃树园煤矿为界分为东侧的桃东沟剖面和西侧的桃西沟剖面。该地区晚二叠世地层称作下仓房沟群,自下而上分为泉子街组,梧桐沟组和锅底坑组,主要为河湖相砂泥质碎屑沉积,剖面连续,层序清晰,动植物化石丰富。本文研究的标本是20世纪80年代笔者参加中国科学院南京地质古生物研究所新疆中新生界研究队期间,采自 吐 鲁 番 盆 地 桃 东 沟 剖 面 向 斜 南 翼 上 二 叠 632 古 生 物 学 报 61 卷 统下仓房沟群梧桐沟组。根据中国科学院南京地质古生物研究所和吐哈石油会战指挥部勘探开发研究大队1994年资料,梧桐沟组划分为5个岩性段,从上至下依次为:上覆地层:锅底坑组底部 杂色泥岩夹数层透镜状砂砾岩,底部为棕黄色厚层砂砾岩 16.22 m 整 合 梧桐沟组 5.以黑色为主的杂色泥岩,底部为黄绿色中厚层状含砂球石英砂岩 12.61 m 4.黄色中厚层状砂砾岩,夹一层砂质灰岩 5.82 m 3.杂色泥岩夹数层灰岩透镜体 15.48 m 2.黑色泥岩夹数层介壳灰岩,底部为黄绿色石英砂岩15.5 m 1.下部为黄色厚层岩屑粗砂岩;上部为黑色碳质泥岩夹数层黄绿色石英砂岩;顶部夹煤线 9.17 m 整 合 下伏地层:泉子街组 上部为黑色碳质泥岩。梧桐沟组的腹足类见有2层,下面一层位于第2岩性段的介壳灰岩层(采集号:ADI-85-711),介壳灰岩层有多层,很薄,约厚13 cm,无层理,有时呈透镜状,介壳以双壳类为主,贝体很小,在岩层中大多呈孤立状(图1)。上面一层位于第3岩性段的灰岩透镜体中(采集号:ADI-85-712),上下两层之间直线距离20 m左右,介壳较下面一层稀少。1989年,Yochelson对梧桐沟组介壳灰岩和灰岩透镜体中的文石进行了详细研究,确认这些灰岩为陆相淡水沉积;并指出这是中国已知的第一个古生代淡水文石产地,也是第一个古生代淡水文石的报道(Yochelson,1989)。介壳灰岩和灰岩透镜体中的腹足类都是相同的,标本个体很小,数量丰富,主要有Xinjiangospira rotundata Yu et Zhu,1990、X.habita sp.nov.、Hydrobia turpanensis Wei,1984、H.orientalis sp.nov.、Pseudamnicola taodonggouensis sp.nov.、Valvata complanusa sp.nov.;共生化石门类有双壳类、介形类、轮藻和叶肢介等,其中双壳类经 图 1 桃东沟剖面晚二叠世梧桐沟组的介壳灰岩层和灰岩透镜体 Fig.1 Shell limestone layer and limestone concretions of the Late Per-mian Wutonggou Formation from the Taodonggou section,Turpan Basin,Xinjiang a.梧桐沟组第二段中的介壳灰岩层(Shell limestone layer from the Member 2 of the Wutonggou Formation);b,c.梧桐沟组第三段中的灰岩透镜体(Limestone concretions from the Member 3 of the Wutonggou Formation).沙金庚研究员鉴定有:Palaeanodonta parallela(Amalitsky)、P.aff.longisima(Netchajew)、P.cf.fishcheri(Amalitsky)、P.dubia?(Amalitsky)、Palaeanodonta sp.、Palaeanodonta sp.nov.、Palaeomutela verneuili(Amalitsky)、Oligondon?geinitzi(Amalitsky)(铰齿清楚,但与典型的少齿蚌有差异),Oligondon?cf.geinitzi(Amalitsky)、?Mi-crodontella elliptica(Khaltfin)(铰齿不明显)等;介形类以Darwinula为主。在梧桐沟组中还见有脊椎动物二齿兽类Jimusaria taoshuyuanensis,Turfanodon bogdaensis等(孙艾玲,1973;赵喜进,1980)。桃树园剖面二叠三叠系的研究历史悠久,古生物研究资料也十分丰富(