广西六景节甲鱼化石

<正> 1973年夏,笔者在横县六景镇北釆获若干节甲鱼化石碎片,其中两件保存不全的刺体,曾以系统位置未定的窄鳞鱼类(又称北极鱼)报道过(刘时藩,1980)。1980年5月,笔者又在原来采集化石的地点和同一层位的另一地点,又采获了数十件鱼化石甲片。化石产于那高岭组的底部的黄绿色、灰色的泥岩和泥灰岩中。经初步观察,这些分离保存不全的甲片,几乎全属于节甲类,其中大多数还应隶属辐纹鱼科(Actinolepidae)。本文先将其可确认者作初步报道,同时对这些鱼化石的系统位置以及有关的地质问题也作初步讨论。     

内蒙古自治区上侏罗统最原始的蠼螋昆虫化石(昆虫纲:革翅目:始螋亚目)

我国上侏罗统牛津阶-基末利阶（163-150Ma)保存有完好的最原始的蠼螋昆虫化石,首次描述,分析和讨论了原始蠼螋后翅脉序特征,认为与现代生存的蠼螋后翅基本相同。因此,提出了与西方某些蠼螋昆虫分类学者不同的意见,认为始螋亚目（Aechidermaptera)应归入于革翅目（Dermaptera)之中,且视其为一个最原始的类群较为合理,内蒙古自治区这个原始类群的下列重要特征皆为首次发现;胸骨具有特殊的形态结构;革翅锁具（Tegmina locking device)和刺脊突（spiny crest)发育;前,中,后足跗节皆为5节;后足基节显著伸长;颈部被划分为前,后两个颈片;革翅后缘收缩变尖,上述5项被视为厚原始蠼螋特有的祖征,下列特征应为早期蠼螋共有的原始性状;虫体扁平,通常具毛;腹部侧缘彼此近平行;触角显长,丝状,多节（通常多于11节）;两只单眼发育;上颚具齿;中胸小盾片显大;革翅较长,通常具有明显的翅脉;股节具隆脊;爪和爪垫通常发育;腹部各节背板与腹板不重叠（两者位置非简单的上,下关系）;尾须柔软,多节,雌性产卵器鞘显著外伸,本文建立了始螋亚目1新科Sinopalaeo-dermatidae和2新属2新种Sinopalaeodermata neimonggolensis gen.et sp.nov,Jurassimedeola orientalis gen,et sp.nov。同时,对蠼螋昆虫的起源和演化重新进行了讨论,做出了与西方某些蠼螋昆虫研究者结论不同的推断。     

An ancient example of Platycladus (Cupressceae) from the early Miocene of northern China: origin and biogeographical implications

A number of cupressaceous fossil leaves are described in this paper that come from the lower Miocene of Inner Mongolia, northern China. These new examples of fossil leaves are compressed, have their branchlets arranged in a plane, either spreading or ascending, and are flat. These specimens also possess scale-like leaves that are dimorphic, preserved facial leaves that are rhomboidal and have obtuse apices, and lateral leaves that are boat-shaped and have slightly incurved apices. The epidermal cells of these fossils are quadrangular, rectangular, or narrowly rectangular, while the leaves are amphistomatic, and stomata are elliptical or oblong, and monocyclic. In comparison with both living and related fossil taxa, we identify the new fossils as Platycladus preorientalis sp. nov. Taken in combination with a molecular phylogenetic analysis, the new fossils suggest that the genus Platycladus originated in the Oligocene in mid and high Asian latitudes. Thus, the ancient Platycladus lineage probably migrated from Europe to Asia following the closure of the Turgai strait during the Oligocene.     

New evidence for laurasian corystosperms: Umkomasia from the Upper Triassic of Northern China

Recent finds of remarkable fossil plants from the Upper Triassic Yangcaogou Formation in Liaoning Province, PR China include branched, cupule-bearing structures referable to the corystosperm ovulate organ Umkomasia. This material is described and assigned to the proposed new species Umkomasia asiatica. The collection includes numerous isolated cupules and fragments of ultimate cupule-bearing axes. Two specimens consisting of portions of the main axis with attached, cupulate lateral axes have also been found. The main axis was at least 6.5 cm long, with each lateral axis bearing one to at least three pairs of stalked, ovoid cupules. The new Umkomasia is similar to U. franconica from the Jurassic of Germany, which is the only other known laurasian species, but the cupules are smaller and more elongated. It is also similar to many gondwanan forms, including the type species U. macleanii. Leaves associated with the Chinese Umkomasia species are tentatively referred to Thinnfeldia, and may have been produced by the same plant. Associated ovoid seeds with elongated, curved micropyles are similar to those of gondwanan species of Umkomasia. The fossils described here are, therefore, significant in representing the first report of corystosperm reproductive structures from Asia, and only the second report of Umkomasia from the entire northern hemisphere. The new Chinese fossils also support leaf-based evidence that the Corystospermales were present in Laurasia as early as the Late Triassic.     

陕西宁强胡家坝地区晚埃迪卡拉世高家山生物群岩相变化与化石保存关系

我国上扬子陕西宁强-勉县境内产出埃迪卡拉纪晚期高家山生物群,根据大量野外追踪、实地观察与室内岩相分析,对碎屑岩相黄铁矿化软躯体化石的出现与岩相横向变化之间的关系以及相应的埋藏相进行初步探讨,认为胡家坝露头带为相对远离风暴源的沉积序列,最利于化石的保存;高家山露头带则属于相对靠近风暴源的沉积序列,化石保存潜力不如胡家坝露头带的沉积序列。     

Proximal metatarsal articular surface shape and the evolution of a rigid lateral foot in hominins

This study quantifies the proximal articular surface shape of metatarsal (MT) 4 and MT 5 using three-dimensional morphometrics. Humans and apes are compared to test whether they have significantly different shapes that are skeletal correlates to comparative lateral foot function. In addition, shod and unshod humans are compared to test for significant differences in surface shape. The MT 4 fossils OH 8, Stw 628, and AL 333-160, and the MT 5 fossils AL 333-13, AL 333-78, OH 8, and Stw 114/115 are compared with humans and apes to assess whether they bear greater similarities to humans, which would imply a relatively stable lateral foot, or to apes, which would imply a flexible foot with a midfoot break. Apes have a convex curved MT 4 surface, and humans have a flat surface. The MT 4 fossils show greater similarity to unshod humans, suggesting a stable lateral foot. Unshod humans have a relatively flatter MT 4 surface compared with shod humans. There is much overlap in MT 5 shape between humans and apes, with more similarity between humans and Gorilla. The fossil MT 5 surfaces are generally flat, most similar to humans and Gorilla. Because of the high degree of shape overlap between humans and apes, one must use caution in interpreting lateral foot function from the proximal MT 5 surface alone.     

陕西镇巴下寒武统水井沱组小壳化石新属种

本文描述了陕西镇巴下寒武统水井沱组中的小壳化石３新属５新种。样品采自镇巴小洋坝曾家坡,共生化石有三叶虫、古介形虫、海绵骨针和大量软舌螺等。化石组合面貌表明其地质时代属筇竹寺期。另外,在峡东水井沱组中发现了微网虫（Ｍｉｃｒｏｄｉｃｔｙｏｎｓｐ．）化石骨片（图版Ｉ,图１８,１９）,可与云南筇竹寺组及陕南水井沱组对比,说明Ｍｉｃｒｏｄｉｃｔｙｏｎ广泛分布于扬子地台区。     

A three-dimensionally preserved fossil polychaete worm from the Silurian of Herefordshire, England.

Polychaete body fossils are rare, and are almost invariably compressed and too poorly preserved for meaningful comparison with extant forms. We here describe Kenostrychus clementsi gen. et sp. nov. from the Silurian Herefordshire Konservat-Lagerstätte of England, in which three-dimensional external morphology is preserved with a fidelity unprecedented among fossil polychaetes. The fossils, which are preserved in calcite, were serially ground and photographed at 30 microm intervals to produce computer-generated reconstructions of the original external surface. The new genus has a generalized polychaete morphology with large biramous parapodia, unspecialized anterior segments and a small prostomium with median and lateral antennae and ventral prostomial palps. Cirriform branchiae arise from the ventral surface of each notopodium, and may be homologous with the inter-ramal branchiae of the extant nephtyids. Through cladistic analysis, Kenostrychus is interpreted as a member of a stem group of either the Phyllodocida or the Aciculata (Phyllodocida + Eunicida). Direct comparison with other fossil forms is difficult, but hints that inter-ramal respiratory structures may be primitive within the Phyllodocida and/or the Aciculata.     

The restoration of flattened fossils

Neither collapse, due to decay in a soft-bodied organism, nor compaction, due to overburden pressure, normally lead to significant lateral expansion in flattened fossils except in the case of some with rigidly mineralized skeletons. The fossils are thus analogous to a variety of two-dimensional views of a three-dimensional object. This realization provides a foundation for drawing and testing a reconstruction using either computer or manual graphic restoration methods. A complementary approach based on the photography of simple models, which is particularly useful where a complex three-dimensional morphology is under study, is described and illustrated by two examples, the Middle Cambrian arthropod Odaraia and the Upper Ordovician graptolite Direllograptus .     

西南极乔治王岛早第三纪遗迹化石

南极乔治王岛始新统化石山组含多种类型遗迹化石,常与鸟类足迹相伴产出。记述的１新遗迹属及所属的５新遗迹种,从遗迹化石形态两侧对称,纵向延伸,缺乏疣足及其它附肢构造等特征看,推测造迹者为软体蠕虫类,很可能属于寡毛纲的动物。这些化石反映了浅水河湖的沉积环境。     

Belowground rhizomes and roots in waterlogged paleosols: Examples from the Middle Jurassic of Beijing,China

Plant rhizomes and roots occur in terrestrial ecosystems since at least the Devonian, but the documentation of belowground plant tissues is sparse in the fossil record. In this study, fossils representing belowground rhizomes and roots are described from the top of the Upper Yaopo Formation (Middle Jurassic), at the Yuejiapo section, Mentougou District, Beijing, China. Morphological studies of the plant fossils, together with lithofacies analyses, provide new information on plant–soil interactions during the Jurassic period. Three types of rooting systems are recognized from two fossiliferous beds. The Bed-1 Flora is interpreted as representing a Cladophlebis-dominated community, where abundant foliage remains mainly of Cladophlebis cf. scariosa and Cladophlebis delicatula are associated with Type-A rooting system. The Bed-2 Flora includes Type-B and Type-C rooting systems, although the floristic composition is unknown due to the absence of identifiable foliage remains. The Type-A and Type-B rooting systems consist of abundant in situ vertical rhizomes, fine shoot-borne roots and lateral roots, and are consistent with those of some extant ferns. The Type-C rooting system shows a thick central taproot and at least three orders of lateral roots, an architecture typical of various gymnosperms. The in situ rooting systems, as well as sedimentary evidence, contribute to the recognition of stacked, reworked Entisols in a dynamic waterlogged environment.     

Upper ordovician turbidites in western Asturias: A facies analysis with particular reference to vertical and lateral variations

Ab Upper Ordovician sandstone—shale sequence in Asturias, Northwest Spain, is analysed with particular regard to lithology, sedimentary structures and trace fossils. It is deduced that deposition of the sandstones was from axially flowing turbidity currents in a deep-water trough. Trace fossils are rare but there is a predominance of deep-water turbidite-facies types including Helminthopsis, Spirophycus, Cosmorhaphe, and Protopaleodictyon. Arenicolites, normally regarded as typical of shallow water, is, however, also recorded. The low abundance and diversity of trace fossils in this succession is in marked contrast to the situation in many younger turbidite sequences.The initiation of turbidite deposition followed a long period of quiet-water mud sedimentation. Recognition of this abrupt facies change in two sections separated by a down-current distance of 40 km, provides a reference level from which vertical and lateral facies changes are quantitatively documented. In each section, deposition starts with a fining and thinning-upwards cycle and continues with several similar cycles. The onset of turbidite deposition, abrupt facies transition, and repetition of the cycles, are probably largely the result of fault block uplift at source, while initial development of the deep-water trough may have resulted from associated downthrow. The lateral facies variations, which include downcurrent reduction in sandstone/shales ratio and the Walker ABC index, probably result from a combination of factors, including reduced flow velocity and decreased sediment load.     

Permian bryophytes of Western Gondwanaland from the Paraná Basin in Brazil

Abstract: This study involves bryophyte fossils from the Teresina Formation (Permian–Guadalupian) collected in the Rio Preto Quarry in the state of Paraná, southern Brazil. Two new genera are proposed, with two new species: Capimirinus riopretensis sp. nov. and Yguajemanus yucapirus sp. nov. C. riopretensis sp. nov. included a lateral sporophyte that was organically attached to a gametophyte and is thus one of the oldest pleurocarpous fossils known today. This discovery provides clear evidence of the evolution of mosses during the Permian, because an acrocarpous moss from this period was also found in India. The preservation of such a fragile structure demonstrates that no prefossilization displacement took place and that the sediments accumulated in a low‐energy, fresh‐water environment, similar to a lake fed by rain, and isolated from the direct influence of the sea. Campimirinus riopretensis may be placed within the earlier pleurocarps, and Yguajemanus yucapirus sp. nov. may belong to the Bryalean families. However, we were not able to place neither of these species in any existing family today.     

The role of mid-palaeozoic mesofossils in the detection of early bryophytes

Recently discovered Silurian and Devonian coalified mesofossils provide an additional source of data on early embryophytes. Those reviewed in this paper are considered of some relevance to understanding the early history of bryophytes while highlighting the difficulties of recognizing bryophytes in often very fragmentary fossils. The first group comprises sporophytes in which terminal sporangia contain permanent dyads and tetrads. Such spores (cryptospores) are similar to those found dispersed in older Ordovician and Silurian strata, when they are considered evidence for a land vegetation of embryophytes at a bryophyte grade. The phylogenetic significance of plants, where the axes associated with both dyad- and tetrad-containing sporangia are branching, a character state not found in extant bryophytes, is discussed. The second group comprises axial fossils, many with occasional stomata, in which central conducting strands include G-type tracheids and a number of novel types of elongate elements not readily compared with those of any tracheophyte. They include smooth-walled, evenly thickened elongate elements as well as those with numerous branching +/- anastomosing projections into the lumen. Some of the latter bear an additional microporate layer, but the homogenized lateral walls between adjacent cells are never perforate. Such cells, which occur in various combinations in central strands, are compared with the leptoids and hydroids of mosses, hydroids of liverworts and presumed water-conducting cells in coeval Lower Devonian plants such as Aglaophyton. It is concluded that lack of information on the chemistry of their walls hampers sensible assessment of their functions and the affinities of the plants. Finally, a minute fossil, comprising an elongate sporangium in which a central cylindrical cavity containing spores and possible elaters terminates in a complex poral dehiscence apparatus, is used to exemplify problems of identifying early bryophytes. It is concluded that further progress necessitates the discovery of pre-Upper Silurian fossils with well-preserved anatomy, as well as a re-evaluation of criteria used to assess existing and new Devonian fossils for bryophyte affinity.     

龙凤山藻在澄江早寒武世生物群中的发现

主要报道了产自云南昆明海口耳材村早寒武世筇竹寺组玉案山段澄江生物群中可能为漂浮生长的宏观藻类化石-心型龙凤山藻（新种）（Longfengshania cordata sp.nov.)和中华豆芽藻（新属、新种）（lantulaformis sinensis gen.et sp.nov)。这些化石的发现进一步显示了澄江生物群种物多样性,为揭示该生物群爆发性演化提供了新的证据。通过对龙凤山藻属亲缘关系的深入比较研究,进一步证明该类化石应归属宏观藻类以及它们遗传上的稳定性、演化上的保守性和环境上的适应性。     

龙凤山藻在澄江早寒武世生物群中的发现

主要报道了产自云南昆明海口耳材村早寒武世筇竹寺组玉案山段澄江生物群中可能为自由漂浮生长的宏观藻类化石--心型龙凤山藻(新种)(Longfengshania cordata sp. nov.)和中华豆芽藻(新属、新种)(Plantulaformis sinensis gen. et sp. nov.).这些化石的发现进一步显示了澄江生物群物种多样性,为揭示该生物群爆发性演化提供了新的证据.通过对龙凤山藻属亲缘关系的深入比较研究,进一步证明该类化石应归属宏观藻类以及它们遗传上的稳定性、演化上的保守性和环境上的适应性.     

陕西南部早寒武世原始锥石类carinachitids两新种记述

对陕西宁强宽川铺地区灯影组宽川铺段原始锥石类carinachitids两个新种Emeiconularia amplicanalis sp.nov.和Carinachites platus sp.nov.进行了记述。外表形态多样、个体大小悬殊的两辐对称、三辐对称和四辐对称的carinachitids系列标本的发现,揭示了陕南地区早寒武世丰富多样的carinachitids生命世界。三辐射对称的Emeiconularia在四川峨眉及陕西南部的震旦-寒武系界线附近都有分布,因而对前寒武纪—寒武纪跨界地层具有划分对比意义。两新种的发现无疑增加了我们对早期锥石类多样性的认识,为证实多样性的刺细胞动物在早寒武世早期已经存在的假说提供了新线索。     

The human cranial remains from Gran Dolina Lower Pleistocene site (Sierra de Atapuerca, Spain).

In this article we study the cranial remains of the late Lower Pleistocene human fossils from Gran Dolina (Sierra de Atapuerca, Spain), assigned to the new species Homo antecessor. The cranial remains belong to at least five individuals, both juveniles and adults. The most outstanding feature is the totally modern human morphology of the very complete face ATD6-69, representing the earliest occurrence of the modern face in the fossil record. The Gran Dolina fossils show in the face a suite of modern human apomorphies not found in earlier hominids nor in contemporary or earlier Homo erectus fossils. There are also traits in the Gran Dolina fossils shared with both Neandertals and modern humans, which reinforce the hypothesis that Neandertals and modern humans form a clade, and that the Gran Dolina fossils are a common ancestor to both lineages.     

华北铜川组爬行动物化石的首次发现及其地层意义

１９９２年,中国科学院古脊椎动物与古人类研究所从人民来信中得知,在山西永和县桑壁镇附近的河沟中发现了陆生四足动物化石。不久古脊椎所的专业人员就到化石产地进行了实地调查,并发掘出了几具保存较好的爬行动物化石。化石保存在坚硬的细砂岩中,已经修理出其中一个头骨（如图１所示）。经初步鉴定,这批化石是一类初龙形类动物,与产自新疆吐鲁番盆地中三叠世克拉玛依组的达板吐鲁番鳄（Ｔｕｒｆａｎｏｓｕｃｈｕｓｄａｂａｎｅｎｓｉｓ）（Ｙｏｕｎｓ,１９７３）关系较近,但是其内颈动脉孔位于基蝶骨侧面,而不是位于腹面,这表明…     

甘肃永昌早二叠世两种科达叶的微细构造及古大气CO_2浓度重建

角质层微细构造是鉴定植物属种的重要特征之一,近年来又在古气候恢复中得到广泛应用。从甘肃永昌下二叠统采获了角质层保存较好的两种科达叶化石,详细分析了表皮微细构造特征,并结合其外形特征进行了属种鉴定:其中一种鉴定为淮南科达(Cordaites huainanensis Chen),另建立了一新种,命名为永昌科达(Cordaites yongchangensis sp.nov.)。本文选取与化石标本的宏观形态和角质层微观形态较为相似的长叶竹柏(Podocarpus fleuryi Hickel)作为其现存最近对应种,初次尝试利用化石气孔特征重建了甘肃永昌早二叠世的古大气CO2浓度。