中国华夏植物区二叠纪几种科达植物分散角质层及其意义

中国华夏植物区科达植物的研究历史虽然最早可上溯至1883年,但直到1991年才首次报道其角质层构造.到目前为止,中国华夏植物区总共描述了4种科达植物原位角质层和3种分散角质层.但与欧美植物区相比,有关中国华夏植物区科达植物角质层的研究工作还较薄弱.本文较详细地描述了3种产自中国华夏植物区二叠纪煤系地层中的科达植物分散角质层.其中2种采自华北亚区南缘的安徽淮南新庄孜矿山西组A1煤顶板,地质时代为早二叠世;另一种采自华南亚区的贵州水城矿区大河边矿龙潭组顶部的11号煤层,地质时代为晚二叠世早期.将这3种科达植物分散角质层与已知的欧美植物区和中国华夏植物区的种类进行了对比,认为它们都是新的类型.讨论了这3种新的科达植物分散角质层所具有的古植物学意义.     

中国华夏植物区的科达植物化石

总结了过去了几十年来,特别是近４０年来有关中国华夏植物区科在植物研究的资料,将中国华夏植物区的科达植物化石归为４种类型：印痕,压型,髓模及矿化化石等。在科达植物各种器官中,分布最广,数量最多,时代延续最长的是其叶化石,最早出现于早石炭世的维宪期（Ｖｉｓｅａｎ）,但数量较少,分布零星。在华北,一直至晚石炭世的斯梯芬期（Ｓｔｅｐｈａｒｉａｎ）和早二叠世,科达中化石数量才逐渐增多,特别在早二叠世,达到最     

云南墨江羊八寨地区晚二叠世晚期植物群

首次比较系统地记述云南墨江羊八寨地区晚二叠世羊八寨组植物化石,共计17属26种.墨江地区晚二叠世晚期植物群新的发现,对该区羊八寨组地质时代判定,以及植物地理分区上都具有重要意义.表明墨江地区晚二叠世植物群的高度分化、繁衍,补充和完善其生物多样性,证明该区在晚二叠世晚期仍然是华夏植物群华南亚区的一部分.     

根据孢粉讨论华夏与安加拉两个植物群的关系

安加拉区一亚安加拉区较特征的至少有八类（或间）孢粉,其中主要是科达类（Cordaitina等）和亚安加拉区起源最早（Bashkirian早期或稍晚）、分异度和丰度最高的种子蕨盾籽类（多肋的Protohaploxypinus,Striatoabieites,Striatopodocarpites,Hamiapollenites和基本无囊的Vittati－na）。安加拉一亚安加拉植物群分子在早二叠世早期已渗透到塔里木盆地,稍晚到甘肃龙首山一带,且往后有类别增多（如松柏类、蕨类）分异度增高的趋势,至晚二叠世晚潮已演变为亚安加拉色彩为主的植物群;华夏植物群本部在二叠纪不同时期的组合中,也有少量安加拉一亚安加拉成分混生,至晚二叠世晚期（石千峰组）有所增强。安加拉一亚安加拉孢粉植物群中却没有典型的华夏分子存在。安加拉一亚安加拉某些植物分子的南迁和繁盛与劳亚大陆的向北漂移和组成中国大陆的诸板块的接近、拼接时代不同密切相关。     

论中国北方晚二叠世混生植物群的区系划分

自昆仑山—阿尔金山—祁连山—秦岭—大别山一线以北的中国北方地区,二叠纪时大约由准噶尔地块、塔里木地块、中朝板块、佳蒙地块等几个主要陆块和一些小的地块(微板块)组成。在系统整理这些地区晚二叠世植物属种的基础上,根据植物群属种的植物学特征及植物地理属性,将中国北方晚二叠世混生植物地理区划分为6个植物地理省,即:1)准噶尔–北塔里木安加拉–华夏混生植物地理省;2)北山–巴丹吉林安加拉–华夏混生植物地理省;3)兴蒙(东北地区)安加拉–华夏混生植物地理省;4)南塔里木安加拉–欧美混生植物地理省;5)祁连–阿拉善华夏–安加拉混生植物地理省;6)华北欧美–华夏–安加拉混生植物地理省。基于各地块在晚古生代各时期植物群的演替和植物区系性质的变迁,结合古地磁资料,简述了各地块在石炭纪—二叠纪时,在古特提斯洋和古亚洲洋中逐渐由低纬度热带亚热带雨林气候区向北半球高纬度温带干旱气候区的漂移和碰撞过程;并认为晚二叠世混生植物群形成的主要原因是各陆块相互间的迁移和拼接,中、晚二叠世形成的联合大陆(Pangaea)给各陆块上植物群的互相交融、侵入提供了良好条件。这种时空关系的改变,导致植物生态系统的改变,不但造成来自不同植物地理区植物的混生,而且产生了不少新的物种和丰富的土著分子。     

中国二叠纪煤核中具解剖构造的鳞木类植物：似土

报道了产于中国二叠纪煤核中的3种具解剖构造的鳞木类叶,它们都具双木质部束,与似封印叶属（Sig-illariopsis Scott)特征一致,与该属已有种进行了对比,确定它们为3个新种：产于山西太原西山煤田太原组上部7号煤层（早二叠世早期）煤核中的山西似封印叶（Sigillariopsis shanxiensis sp.nov.)和太原似封印叶（S.taiyuanensis sp.nov.)以及产于贵州水城矿区汪家寨组1号煤层（晚二叠世晚期）煤核中的贵州似封印叶（Sigillariopsis gruizhouensis sp.nov.)。根据煤核中共生的鳞木类植物其他器官以及欧美植物区鳞木类植物的研究资料推断,它们可能属于封印木属（Sigillaria Brongniart)的叶,在国外（主要是欧美植物区）,封印木属植物主要分布于石炭纪,见于二叠纪的封印木很少,华夏植物区的封印木属过去很少发现,其叶和生殖器官均未报道过,本是首次报道华夏植物区具解剖构造的封印木属的叶,它们的发现不仅丰富了华夏植物区封印木属植物的内容,而且对于研究封印木属的演化以及华夏植物区与欧美植物区鳞木类植物之间的关系也具有重要的意义。     

晚古生代的科达科——起源和演化的研究

科达科Cordaitaceae植物广泛分布于晚古生代的欧美植物区和华夏植物区,目前包括3个自然属：Mesoxylon、Pennsylvanioxylon和Shanxioxylon。根据目前资料,欧美植物区只见有前两个属,而在华夏植物区这3个属则都有分布。本文详细讨论了这3个属的茎的初生构造、雄性球果穗及胚珠,认为在这3个属中Mesoxylon最原始,Pennsylvanioxylon较进化,Shanxioxylon的茎的初生构造虽具一定的原始性(如具中始式叶迹),但其生殖器官却相当进化。因此,本文提出Shanxioxylon是一种可塑性较强的科达植物,能够适应环境的变化,最终有可能演化为新的植物类群,如某种早期的松杉类;Pennsylvanioxylon则是一种较为特化的植物,其结局是走向绝灭。结合地层中科达科化石的分布情况,本文认为最早出现的科达植物应是Mesoxylon,它可能是由某种前裸子植物演化而来,再由其演化至Shanxioxylon和Pennsylvanioxylon。由于气候和地理环境的不同,华夏植物区和欧美植物区的科达植物各自沿着不同的路线进行演化。其中,欧美植物区科达科的演化路线可能为：某种前裸子植物→Mesoxylon的较原始类型(如M．multirame,Mitrospermum bulbosum)→Mesoxylon的较进化的类型(如M．thompsonii)→Pennsylvanioxylon的较原始类型(如P．iowense)→Pennsylvanioxylon的较进化类型(如P．nauertianum,P．birame)→绝灭。华夏植物区科达植物的可能的演化路线则为：某种前裸子植物→Mesoxylon→Shanxioxylon→Pennsylvanioxylon→绝灭,或某种前裸子植物→Mesoxylon→Shanxioxylon→绝灭或演化为某种新的植物,如某种早期的松杉类。     

塔里木盆地二叠系孢粉组合及生物地层学*

首次系统地研究了塔里木盆地二叠系孢子花粉，讨论了盆地各地层分区孢粉组合特征，建立了从早二叠世至早三叠世早期的6个孢粉组合带，阐述了各组合带孢粉学特征。依据对盆地二叠纪孢粉植物群组成分子的分析及其与国内外相关孢粉组合的比较研究，将盆地孢粉植物群分为3个发展阶段，即：早二叠世早、中期的欧美型植物群，早二叠世晚期至晚二叠世早期的安加拉欧美混生型植物群和晚二叠世中、晚期的安加拉型植物群。文中还从孢粉地层学角度论述了沙井子组、杜瓦组和普司格组的地质时代以及二叠/三叠系界线等问题。描述孢粉25属33种（含2新种）。     

中国二叠纪煤核中具解剖构造的鳞木类植物:似封印叶属(英文)

报道了产于中国二叠纪煤核中的 3种具解剖构造的鳞木类叶 ,它们都具双木质部束 ,与似封印叶属 (Sigil lariopsisScott)特征一致。与该属已有种进行了对比 ,确认它们为 3个新种 :产于山西太原西山煤田太原组上部 7号煤层 (早二叠世早期 )煤核中的山西似封印叶 (Sigillariopsisshanxiensissp .nov .)和太原似封印叶 (S .taiyuanensissp .nov .)以及产于贵州水城矿区汪家寨组 1号煤层 (晚二叠世晚期 )煤核中的贵州似封印叶 (Sigillariopsisguizhouensissp .nov .)。根据煤核中共生的鳞木类植物其他器官以及欧美植物区鳞木类植物的研究资料推断 ,它们可能属于封印木属 (SigillariaBrongniart)的叶。在国外 (主要是欧美植物区 ) ,封印木属植物主要分布于石炭纪 ,见于二叠纪的封印木很少。华夏植物区的封印木属过去很少发现 ,其叶和生殖器官均未报道过。本文是首次报道华夏植物区具解剖构造的封印木属的叶 ,它们的发现不仅丰富了华夏植物区封印木属植物的内容 ,而且对于研究封印木属的演化以及华夏植物区与欧美植物区鳞木类植物之间的关系也具有重要的意义。     

中国二叠纪煤核中具解剖构造的鳞木类植物:似封印叶属

报道了产于中国二叠纪煤核中的3种具解剖构造的鳞木类叶,它们都具双木质部束,与似封印叶属(Sigillariopsis Scott)特征一致.与该属已有种进行了对比,确认它们为3个新种:产于山西太原西山煤田太原组上部7号煤层(早二叠世早期)煤核中的山西似封印叶(Sigillariopsis shanxiensis sp. nov.)和太原似封印叶(S. taiyuanensis sp.nov.)以及产于贵州水城矿区汪家寨组1号煤层(晚二叠世晚期)煤核中的贵州似封印叶(Sigillariopsis guizhouensis sp.nov.).根据煤核中共生的鳞木类植物其他器官以及欧美植物区鳞木类植物的研究资料推断,它们可能属于封印木属(Sigillaria Brongniart)的叶.在国外(主要是欧美植物区),封印木属植物主要分布于石炭纪,见于二叠纪的封印木很少.华夏植物区的封印木属过去很少发现,其叶和生殖器官均未报道过.本文是首次报道华夏植物区具解剖构造的封印木属的叶,它们的发现不仅丰富了华夏植物区封印木属植物的内容,而且对于研究封印木属的演化以及华夏植物区与欧美植物区鳞木类植物之间的关系也具有重要的意义.     

The Cordaitean Fossil Plants from Cathaysian Area in China

The cordaitean plants distributed throughout the Carboniferous and Permian of Cathaysian in China. There are four modes of the cordaitean plant preservation, viz. by impression, compression, pith cast, and permineralization. The cordaitean plants preserved by the respective types are listed as follows: 1. By impression, Cordaites principalis, C. schenkii, C. borassifolia, C. vetted, C. sandlimorpha, C. linsiana, C. yujiaensis, C. albostriata, C. linearis, C. dengfengensis, C. oblongifolius; Cordaitanthus volkmannii, C. curtus, C. taiyuanensis, C. rigidus, C. digymois ; 2. By compression, Cordaites baodeensis, C. huainanensis, and one unnamed cuticle of Cordaites in the coal of Taiyuan Formation from Xuzhou Coalfield, Jiangsu Province; 3. By pith cast, Artisia approximata; 4. By pennineralization, including four organ assemblages in the coalballs, namely Shanxioxylon sinense assemblage, Sh. taiyuanense assemblage, Pennsylvanioxylon tianii assemblage and Penn. cf. nauertianum assemblage; and one silified cordaitean stem Dadoxylon ( Cordaites ) sahnii with a septate pith. Cordaitean leaves appeared at first in Visean (Early Carboniferous), but they did not become common until Stephanian (Late Carboniferous) and Early Permian and distributed throughout the south, north and northwest of China. Especially in Taiyuan Formation, Shanxi Formation and Lower Shihezi Formation, up to 13 species of the cordaitean leaves have been recorded. Besides some large leaves, such as Cordaites principalis and C. schenkii etc. and several small ones, such as C. vetteri, C. sandlimorpha, C. linsiana, C. albostriata, C. dentgfengensis and C. oblongifolius appeared in Early Permian. In the early kate Permian, cordaitean leaves were abundant only in the southern part of North China and some places of South China. And they became few in the late Late Permian in the whole region of Cathaysian Flora in China. Cones and seeds of cordaites now are mainly reported from the Lower Permian in north and northwest of China and so did the permineralized cordaitean plants.     

A new species of the marattialean fern Scolecopteris (Zenker) Millay from the uppermost Permian of Guizhou Province, south-western China

Several isolated marattialean synangia and sporangia are reported from coal balls collected from Coal Seam No.1 (C605) in the uppermost Permian Wangjiazhai Formation in Guizhou Province, south-western China. The synangia are radially symmetrical with diameters between 0.8 and 1.2 mm and are 1.7 mm long, consisting of 3–4 elongate sporangia that are fused basally, free distally and possess a pointed apex. The outer-facing sporangial wall is 4–5 cells thick and conspicuously differentiated. Spores are trilete, have a granular ornamentation and are nearly round equatorially with a diameter of 55–60 µm. Comparisons with other anatomically preserved Palaeozoic marattialean synangia from the Euramerican and Cathaysian floras permit their assignment to the genus of Scolecopteris (Zenker) Millay. In this species the thick, outer-facing sporangial walls and large trilete spores are features consistent with those of the Oliveri Group within Scolecopteris , a group that has previously been considered primitive within this genus. Distinctions from all other previously recognized species within the Oliveri Group lead to the creation of a new species, S. guizhouensis sp. nov. This species is the youngest of the reported species of Scolecopteris recognized from the Euramerican and Cathaysian floras, and provides important evidence on the organization of marattialean ferns from the Upper Permian strata of south China.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 151 , 279–288.     

New species of the isolated Psaroniaceous rachis from the Early Permian in China

A new kind of marattialean raches are reported from the coal balls in Coal Seam No.7 in the upper part of the Taiyuan Formation （early Early Permian） from Taiyuan, Shanxi, China and are assigned to the genus Stipitopteris Grand＇Eury （Psaroniaceae）. The present specimens are different from all six reported species of the genus, and are therefore proposed as a new species： Stipitopteris shanxiensis. The raches of the new species are generally dorsi-ventrally flattened. The main raches usually exhibit scales of different forms on their surface. Beneath the epidermis is a zone of parenchymatous cells, some of which contain tannin-like contents. Inside this is a zone of small sclerenchymatous cells. Inward are the ground tissue and vascular bundles. The vascular bundles are continuous and are in two circles： the outer circle assumes a transversely elliptical shape with the gap and pinna trace, and the inner circle assumes a shallow C.shape with inrolled ends. The ground tissue located at the inner side of the vascular bundle is composed of thicker-walled parenchymatous cells. The cells of the ground tissue are vertically elongated in longitudinal sections. Subordered raches are smaller and have simpler structures than the main raches. The parenchyma zone beneath the epidermis is thinner, usually one to two cells wide and the sclerenchyma zone is usually absent. The scales are poorly developed and there is only one C-shaped vascular bundle. The new species is comparable to the crosiers of Psaroniaceae of the Euramerican Flora in some aspects, for example, it has a dorsi-ventrally flattened rachis and scales on the surface of the rachis. However, the other features and the preservative conditions of the present specimens indicate that they are not crosiers, but fully developed or mature raches. The new species is the first well-studied anatomically-preserved rachis of Psaroniaceae from the Cathaysian Flora and bears significance not only in understanding the anatomy and taxonomy of Psaroniaceae in the Cathaysian Flora, but also in the relationship between the Euramerican Flora and the Cathaysian Flora.     

蹄痕茎属在内蒙古乌达地区的发现及其意义

描述了发现于我国内蒙古乌达地区早二叠世早期山西组新种乌达蹄痕茎（Ｃａｕｌｏｐｔｅｒｉｓｗｕｄａｅｎｓｉｓｓｐ．ｎｏｖ．ＳｕｎｅｔＤｅｎｇ）。蹄痕茎为石炭纪和二叠纪树蕨植物的茎干印痕化石,多分布于欧美植物区,在华夏植物区则非常少见。本新种的发现为蹄痕茎植物的地理分布、生态和演化提供了重要的证据。     

山东南部太原组一种新的具解剖构造的鳞木目茎--Diaphorodendron rhombicum sp.nov.

报道了产于山东枣庄矿区太原组16号煤层煤核(早二叠世早期或晚石炭世晚期)中一种具解剖构造的鳞木目茎.茎呈压扁状,长轴约6 cm,短轴约2.5 cm.中柱、外部皮层、周皮和叶座均保存.茎具原生中柱,无次生木质部发育,外部皮层由较发育的径向的厚壁的细胞条带和已经毁坏的薄壁的细胞区域交替排列构成.周皮较发育,厚约4～5 mm,由木栓层和栓内层构成.其中栓内层较厚,细胞构造均一,或在有些地方分化为弦向的薄壁的细胞条带和l厚壁的细胞条带,二者交替排列.其中薄壁的细胞条带常保存不好而形成弦向的裂隙.叶座的高和宽近相等,呈近正菱形.叶痕盔形或双凸镜形,位于叶座上部,微微突出于叶座表面之上.叶座表面平坦,未见明显的中脊和横皱纹.叶迹在叶座内近水平状延伸,但在近叶座表面处略向上然后向外弯曲成不太明显的"S"形进入叶痕内.径切面上叶舌穴略向上斜伸,具一宽大的基部,其开口直接位于叶痕顶角处.叶舌大,宽卵球形,长轴达1.2 mm,短轴达1 mm.与目前已知的鳞木目几个属的茎比较,当前标本与Diaphorodendron属的茎最为接近,仅在叶座上有些不同,本文将其归入该属内.Diaphorodendron属目前共有3个种,全分布于欧美植物区晚石炭世中期(威斯法期),它们与当前标本区别明显,因此,将当前标本归入新种D.rhombicum内.本文是国内首次报道Diaphorodendron属在华夏植物区的存在.其高和宽近相等的叶座形态可能表明了一种进化的特征,这从其所在地层的地质时代(早二叠世早期或晚石炭世晚期)较欧美植物区的3个种(晚石炭世中期)较新这一事实得到支持.     

河南固始下石炭统杨山组华夏木一新种

描述河南固始杨山煤矿下石炭统杨山组的一个华夏木新种Cathaysiodendronyangshanensesp.nov.,这是近年来继在甘肃靖远早石炭世臭牛沟组中发现华夏木之后该属在早石炭世地层中的又一发现。华夏木属是华夏植物群的特有分子,它在早石炭世的发现对探讨华夏植物群的起源有重要意义。     

Callospermarion ovules from the Early Permian of northern China: palaeofloristic and palaeogeographic significance of callistophytalean seed-ferns in the Cathaysian flora

A distinctive kind of anatomically preserved cardiocarpalean ovule is described from the Early Permian Taiyuan Formation of northern China. Ovules are small, have 180° rotational symmetry, and possess variably thick integuments with prominent secretory cavities that may be empty, filled with resinous materials and in several instances appear to contain animal coprolites. Comparisons show that (where known) these features conform to those of Callospermarion undulatum (Neely) Rothwell, to which they are assigned, previously only known from the Pennsylvanian of Euramerica. These fossils represent the first indisputable occurrence of the genus Callospermarion in the Early Permian Cathaysian floras, and show the presence of callistophytalean seed-ferns in this palaeofloristic realm for the first time. These data combined with results from previous investigations now support the Early Permian northern Cathaysian flora including the Taiyuan Formation having evolved from the Late Carboniferous and earliest Permian Euramerican flora, with which it shares far too many generic level similarities for these co-occurrences to be coincidental. Our hypothesis is therefore that the Early Permian flora of the northern Cathaysian realm represents the continued evolution of wetland Euramerican-type coal-swamp floras, and as such is likely to present a model for evolutionarily driven floral change as opposed to the climatically driven floral changes observed in the Euramerican flora after the demise of coal-swamp environments. The distribution of coprolites in and immediately around glandular cavities in this species suggests specialised syndromes of herbivory existed in Early Permian Cathaysian ecosystems, with herbivores preferentially selecting these areas of the ovule integument.