贵州台江早寒武世台江动物群的发现及意义

贵州台江八郎凯里组剖面中下部中、下寒武统界线之下厚达１５米左右的粉砂质泥岩、页岩中存在着一个类似凯里动物群的台江动物群,由８个门类３９个属组成,核心为蠕形动物,三叶虫数量很多。形成于内陆棚浅海环境。时代为早寒武世末期,介于著名的早寒武世早期澄江动物群和中寒武世早期凯里动物群之间,对于早期后生动物的演化研究具有重要的意义。     

盘县动物群研究进展

盘县动物群是以保存完整、精美、属种丰富的海生爬行动物化石为特色,伴生海生 无脊椎动物化石的一套完整的珍稀古生物群落。盘县动物群产于中三叠统关岭组上段,属于 牙形石Nicoraella kockeli带,时代为中三叠世安尼期的Pelsonian亚期,早于著名的 意大利—瑞士交界处Monte San Giorgio地区的Grenzbitumenzone动物群（安尼阶—拉丁阶界线 附近）,是目前世界上中三叠世最老的海生爬行类动物群。它的发现和研究填补了海生爬行动 物演化的早期链条,增强了人们对海生爬行动物各类群的起源、演化、系统发育、古生物地 理以及动物群特异埋藏理论的认识。近期研究表明,盘县动物群中的海生爬行动物：（1） 具有较高的分异度,已报道5属5种,拥有了目前发现的最古老的混鱼龙科分子、鸥龙属分子、 较老的幻龙属分子和真正适应水生生活的原龙类以及诸多未描述的类群;（2） 动物群多由 适应近岸浅水环境的类群组成,在面貌上呈现出强烈的西特提斯生物亲近性;（3） 动物群属 特异埋藏,赋存层分布有4～5层凝灰岩,化学特征分析显示存在7次火山间歇性喷发活动,火 山活动导致的生态环境急剧恶化可能是动物群集群绝灭的直接诱因。     

武当山块北缘晚震旦世—早古生代沉积盆地的构造沉降分析

运用盆地分析方法,着重研究了武当山块北缘晚震旦世—早古生代沉积盆地的构造沉降问题．构造沉降分析表明：晚震旦世属盆地同裂谷期沉降阶段;早、中寒武世为被动式衰减热沉降阶段;晚寒武世—中奥陶世为构造上升阶段．     

矿产资源

正贵州地质历史时期不同的海洋古地理格局形成独特优势矿产资源。古生物化石瓮安生物群:震旦纪陡山沱期(距今约6～5.8亿年),瓮安地区出现目前世界最早的多门类宏体生物群。凯里动物群:中寒武世早期(距今约5.2亿年),凯里地区出现11大门类、120多属动物群。为生命起源与演化、寒武纪生物大爆发提供了重要证据。     

四川峨眉高桥震旦系——寒武系界线

四川峨眉高桥震旦系—寒武系界线剖面构造简单,沉积连续,化石丰富,是我国研究震旦系与寒武系界线重要剖面之一。本文系统地介绍了峨眉山地区震旦系—寒武系的研究历史,剖面详细分层及岩性和生物特征。论述了本区晚震旦世至早寒武世初期沉积环境的变迁、生物演化及震旦系—寒武系界线划分。本文以首次多门类带壳动物的大量出现作为划分震旦系与寒武系界线的主要依据。寒武系的下界划分在麦地坪组下部以小壳动物Anabarites—Circotheca为代表的化石组合的底界上,并与国内外相当时代的地层及界线进行了对比。     

和政动物群见证青藏高原的隆起

和政动物群是指我国甘肃省和政地区发现的新生代古生物化石所代表的动物群。和政县位于兰州市南偏西约100千米处,行政上属于甘肃省临夏回族自治州。在地质学和古生物学上常常把发现在同一地方、同一时代的各种古生物化石组合统称为一个动物群,并经常以发现地或其代表动物命名。比如,著名的热河动物群就是发现于辽宁西部及华北地区白垩纪早期的一个古动物群,其中包括中华龙鸟等带羽毛的恐龙、孔子鸟等中生代鸟类以及哺乳动物和两栖动物等。后来,科学家在该地区的相同地层中还发现了大量植物化石,包括被人们称为第一朵花的"辽宁古果"等被子植物化石,于是科学家将热河动物群更名为热河生物群,即包括动物群和植物群的生物群。另外,三叠纪晚期的关岭生物群和中新世的山旺动物群等也是如此命名的。     

生物圈演化事件与地球圈层演化的相关性问题

讨论了地史中主要生物类型出现,生物爆发和显生宙５次大的生物集聚群绝灭等生物圈演化事件与地球圈层演化的关系,这些生物圈事件包括生命起源与无核生物的发展,原核生物和真核生物的出现,后生动物的出现,带壳后生动物的出现,寒武纪早期的生物大爆事件以及晚奥陶世,晚泥盆世,晚二叠世,晚三叠世和白垩纪末期的生物集群绝灭事件。在讨论显生宙５次大的生物集群绝灭的可能原因时,把地内原因与地外原因结合起来,阐述了地史中生     

蓟县发现15亿年前遗迹化石

中国地质大学(北京)高建华、蔡克勤等最近在天津市蓟县长城系发现最古老的遗迹化石。这一发现,对我国上前寒武系的划分、对比及沉积环境的研究,以及探讨地球上后生动物的起源和演化,都有极重要的意义。     

甘肃环县楼房子晚更新世孢粉组合

一九六三年初夏,我系黄土科研组,在环县楼房子附近,环河一级支流合道川柏林沟二级阶地沉积物中,发现了丰富的哺乳动物化石,经薜祥煦同志鉴定有:披毛犀(Coelodonta antiguitatis)、赤鹿(Cervus elaphus)、原始牛(Bos primigenius)、盘羊(Ovis ammon)等喜寒动物群。这个动物辟除缺象类化石外,其余与萨拉乌苏动物群相同,时代当属晚更新世。孢粉取样直接来自埋藏该动物群的剖面中。本文试图通过孢粉分析,了解当时的植被,再现古气候、古地理,不但具有一定的科学价值,也是寻找各种沉积矿产的一种值得注意的方法。     

山西襄汾县赵店动物群的发现及初步研究

赵店动物是作者近年来的一个新发现，本文对赵店动物群的化石类型，沉积特征、生态环境和地层时代等进行了初步研究，提出这一动物群生态于中更新世晚期（相当于大洋氧同位素阶段６）。赵店动物群的发现对研究这一时期生物演化及环境变化具有重要价值。     

Progress and significance in research on the early Middle Cambrian Kaili Biota, Guizhou Province,China

Important progress in research on the Kaili Biota has been made recently. Many interesting components from Chengjiang Biota and Burgess Shale Biota have been discovered, e.g. Microdictyon of lobopodia; Ottoia, Palaeoscolex of worms; Naraoia, Marrella of Trilobitioidea, Mollisonia, anamalocarids and other non-trilobite arthropods; and new sorts of echinoder-mas, macroalage fossils and so on. Recent work on the Kaili Biota has resulted in the following developments: (i) an increase in the number of animal genera, up to more than 100 genera in total, so that the Kaili Biota has become the third most diverse of the Burgess Shale-type Biota after the Burgess Shale and Chengjiang Biotas; and (ii) the most noteworthy fossils in the Kaili Biota are echinoderms, non-trilobite arthropods and soft-bodied medusiform fossils, especially the most diverse echinoderms. The progress provides envidence for the biodiversity of marine organisms presented after the "Cambrian Explosion" and serves as a link between the earlist Cambrian Chengjiang Biota and late early Middle Cambrian Burgess Shale Biota. It is of great significance in the reconstruction of the Cambrian palaeoplate, palaeongeography and in research on taphonomy.     

The occurrence of the genus Marrella(Trilobitoidea) in Asia

An important discovery in the Kaili Biota has been made recently, and many interesting components from ChengjiangBiota and Burgess Shale Biota have been discovered. Among them Marrella, only known from mid-Middle Cambrian Burgess Shale Biotaof British Columbia, Canada, is one of the most important arthropods fossils. Because the Kaili Biota is older than the Burgess Shale Biota,the strange head shield of Marrella occurring in the Kaili Biota outside Laurentia ranges from mid-Middle Cambrian to early Middle Cam-brian and is significant for the reconstruction of palaeogeography and evolutionary study of early metazoa. In the present paper Marrellasp. is reported for the first time in Asia.     

贵州寒武系棘皮动物研究新进展及其组合特征

贵州寒武系含有丰富的棘皮动物化石,其中凯里组及杷榔组中的始海百合数以千计.近期贵州下司淑里村杷榔组上部粉砂质泥岩中发现的新类型殷氏原始球状始海百合（新属、新种）Protogloboeocrinus yini （gen.et sp.nov.）,使贵州寒武系棘皮动物分异度加大,达8属、种及1科、属、种未定,分属3个亚门.演化趋势是：类群增多,始海百合个体变小,缝孔变圆,吸盘附着的化石类型增多,生态日趋复杂.凯里生物群也是棘皮动物大辐射的窗口.     

Sponge fossil assemblage from the Early Cambrian Hetang Formation in southern Anhui

Abundant well-preserved large articulated sponge fossils and isolated spicules have been reported from the Early Cambrian Hetang Formation, southern Anhui Province. This unique epifaunal fossil assemblage dominated by articulated sponge fossils is called the Xidi Sponge Fauna. The sponge fauna lived in a quiet oxygenic environment below the storm wave base. Bloom of phytoplankton and rapid sedimentation rate resulted in the deposition of the black shales. Sufficient food supply, lack of other competitors, abundant ecological niches, and demand for oxygen during early Cambrian were in favor of the diversification and evolution of large sponges in the Early Cambrian.     

An Early Cambrian tunicate from China

Like the Burgess Shales of Canada, the Chengjiang Lagerst?tte from the Lower Cambrian of China is renowned for the detailed preservation as fossils of delicate, soft-bodied creatures, providing an insight into the Cambrian explosion. The fossils of possible hemichordate chordates and vertebrates have attracted particular attention. Tunicates, or urochordates, comprise the most basal chordate clade, and details of their evolution could be important in understanding the sequence of character acquisition that led to the emergence of chordates and vertebrates. However, definitive fossils of tunicates from the Cambrian are scarce or debatable. Here we report a probable tunicate Cheungkongella ancestralis from the Chengjiang fauna. It resembles the extant ascidian tunicate genus Styela whose morphology could be useful in understanding the origin of the vertebrates.     

Preliminary notes on softbodied fossil concentrations from the Early Cambrian Chengjiang deposits

The Chengjiang fauna has played a pivotal role in our understanding of the origin and diversification of metazoans since its discovery in 1984. To date, this fauna has been documented as consisting of 121 genera with 140 species belonging to 24 phyla[1-27]. The geo- graphic distribution of the Chengjiang fauna has been expanded from Chengjiang County to eastern Yunnan Province including Haikou, Malong, Yiliang, Anning and elsewhere[25-33], with about 20 localities in to- tal[25,33]. Succes…     

Discovery of Corallina fossil from the Middle Cambrian of Taijiang County, Guizhou Province, China

Abundant and well-preserved macroalgae fossils have been discovered in silty mudstones and shales from the Middle Cambrian of Taijiang County, Guizhou Province, China. CorallinaParaamphiroa siniansis gen. et sp. nov. in the Kaili Fm., is the earliest Corallina fossil, which usually coexists with other carbonaceous macroalgae fossils on the bedding planes of mudstone and shale and is different from the calcareous and phosphatized Precambrian-Cambrian thallus discovered in the Lower Cambrian of Siberia and the Doushantou phosphate rocks of Weng’an County, Guizhou Province, China. The discovery of calcified thallus in the Kaili Fm. bears great importance on the study of phylogeny and evolution of early calcareous macroalgae.     

Proposal and prospects for the global Lower-Middle Cambrian boundary

In recent years paleontologists have been working on the global stratotype section and standard point (GSSP) for the Lower-Middle Cambrian boundary in North America, China, Morocco, Spain and Russia. Continually, they suggest the potential first appearance datum (FAD) of the Middle Cambrian, such as Oryctocephalus indicus, Ovatoryctocara granulata, Acadoparadoxides mureroensis, Hupeolenus and Arthricocephalus chauveaui as being relevant to the potential stratotype section for the Lower-Middle Cambrian boundary. There are only a few trilobites distributed widely enough in the Early to Middle Cambrian connection, so virtually no trilobite(s) can act as the FAD for the global Middle Cambrian. The easily identified Oryctocephalus indicus is widely distributed in three realms of the global Cambrian. Its first appearance position is linked to the extinction of old species coevolution of new ones. It appears to be a comparatively good FAD of Middle Cambrian. The continuous and unbroken Wuliu section (Balang, Taijiang County, Guizhou Province, China) includes O. indicus and co-occurs with many benthic and nektonic trilobites. The evolution of acritarchs in the section, the changed characteristics of trace elements (REE and C isotopes) are generally consistent with the evolution of trilobites both above and below the boundary. Strata above the boundary yield the famous Kaili Biota. The Wuliu section is easily accessible from a main highway.