EVOLUTION OF THE CASUARINACEAE: MORPHOLOGICAL COMPARISONS OF SOME EXTANT SPECIES

The Casuarinaceae consists of the 4 genera Gymnostoma, Ceuthostoma, Casuarina and Allocasuarina. All the genera are found living today in Australia, Malaysia, Melanesia, and Southeast Asia. An abundant and widespread fossil record of the genus Gymnostoma is known from New Zealand, Argentina, South Africa, and Australia. This paper provides a compilation of basic vegetative and reproductive morphological data of the 4 genera of the Casuarinaceae with special emphasis on these features in Gymnostoma. The features are presented in tabular form and the data are compared and discussed. Most of the genera can be clearly distinguished by the morphology of their vegetative and reproductive organs. Species differences within the extant genera often are difficult to distinguish; therefore, comparative systematic analysis of these fossils from fragmentary and incomplete remains ranging through time will be very difficult, and care must be taken when interpreting evolutionary trends from them.     

晚三叠世台形牙形刺分子的演化

晚三叠世台形牙形刺分子属有Ｐａｒａｇｏｎｄｏｌｅｌｌａ,Ｍｅｔａｐｏｌｙｇｎａｔｈｕｓ,Ａｎｃｙｒｏｇｏｎｄｏｌｅｌｌａ和Ｅｐｉｇｏｎｄｏｌｅｌｌａ。这些属都源于中三叠世,可能来自同一根源──Ｎｅｏｇｏｎｄｏｌｅｌｌａ,但有两个不同的演化趋向。本文认为这些台形分子分类演化上最重要的形态特征仅是一些微小的变化,如齿台下方后龙脊─基部附着面,基穴和环台面的细部变化。对Ｍｅｔａｐｏｌｙｇｎａｔｈｕｓ属台形分子的发展演化作了专门讨论,指出了晚三叠世台形牙形刺分子的演化系统。     

下扬子区奥陶纪牙形刺多样性演变初探

根据前人和作者现有资料,对下扬子地区,特别是宁镇地区奥陶纪已经报道的牙形刺属种进行厘定,并按牙形刺带逐带进行多样性统计分析,初步编制出该地区奥陶纪牙形刺属种的地层延限表.研究表明;下扬子区牙形刺在奥陶纪的宏演化经历了3次较明显的辐射事件,分别发生在特马豆克期晚期-弗洛期早期(Serratognathus diversua带)、大坪期早期(Baltoniodus triangularis带)、达瑞威尔期晚期(Eoplacognathus suecicus带);此外,还经历了2次快速增长期,分别发生在达瑞威尔期早期(Lenodus antivariabilis带)、桑比期晚期至凯迪期早期(Hamarodus europaeus带),后者可能与局部环境变化有关.研究表明:华南海平面升降对下扬子区牙形刺宏演化趋势有重要影响.     

ON THE STRUCTURE OF CALAMOSTACHYS BINNEYANA FROM THE LOWER PENNSYLVANIAN OF NORTH AMERICA

The discovery of specimens of Calamostachys binneyana in Lower Pennsylvanan petrifaction material in North America has provided additional information about the structure of this calamitean fructification. The cones consist of regularly spaced alternating whorls of bracts and sporangiophores. Bracts are fused in a disc except at the margin where the individual units become free. Sporangiophores are inserted at right angles to the cone axis and bear four axially directed sporangia. The vascular system of the North American specimens differs from that in other reports of the taxon in the presence of twelve vascular bundles in the cone axis. Each sporangiophore is supplied by a single vascular trace that departs from one axial bundle. There appears to be no constant relationship between the number of vascular bundles and the number of bracts. Spores are spherical, thin-walled, and of the Calamospora type. Relationships with other structurally preserved members in the genus are discussed in light of the diversity in structure demonstrated by the new specimens.     

A NEW SPECIES OF ARTHROXYLON (CALAMITACEAE) FROM THE PENNSYLVANIAN OF KANSAS

Cridland , Arthur A. (Kansas U., Lawrence.) A new species of Arthroxylon (Calamitaceae) from the Pennsylvanian of Kansas. Amer. Jour. Bot. 46(10): 709–712. Illus. 1959.—Arthroxylon resinaceum sp. nov. is described from 3 specimens found in a coal-ball collected at West Mineral, Kansas. The tracheids have 1 or 2 rows of pits on the radial walls and the pith cells adjacent to the protoxylem canals are filled with brown contents. Fungus spores are present in the tissues of 1 specimen.     

一个重要的蒙古二叠纪牙形刺种

在蒙古南部Lugiingol剖面卢金格尔(Lugiingol)组下部发现牙形刺Mesogondolell aidahoensis,该地层应归入下二叠统空谷阶,而不是像以前那样归入上二叠统。     

TRIGONOCARPUS LEEANUS,A NEW SPECIES FROM THE MIDDLE PENNSYLVANIAN OF SOUTHERN ILLINOIS

A new species of Trigonocarpus Brongniart is described from the level of the Herrin (No. 6) Coal (Carbondale Formation, Kewanee Group) at Carterville, Illinois. The seed is three dimensionally preserved by authigenic cementation and exhibits a well preserved nucellar cast, integument and micropylar region. The specimen represents the largest pteridosperm compression-impression seed collected in North America and measures 10 cm from the apex of the micropyle to the chalazal end, and at least 5 cm in breadth. Trigonocarpus leeanus sp. n. is compared to the remaining forty-three taxa within the genus, and specifically with Trigonocarpus grandis Lesquereux, the one species with dimensions approaching it. An emended diagnosis, with designation of a lectotype, is presented for Trigonocarpus grandis. Correlation of the features displayed by Trigonocarpus leeanus sp. n. and the petrified taxa within Pachytesta Brongniart is attempted.     

STUDIES OF PALEOZOIC MARATTIALEANS: AN EARLY PENNSYLVANIAN SPECIES OF THE FERTILE FERN SCOLECOPTERIS

Remains of the fossil Marattiales are very rare in Lower Pennsylvanian sediments. The present report describes a new species of the fertile fern foliage Scolecopteris from the Lewis Creek, Kentucky locality (Lower or lower Middle Pennsylvanian). Scolecopteris conicaulis n. sp. has radial synangia composed of a ring of 4–7 elongate, exannulate sporangia. Most features of the synangia of S. conicaulis were previously hypothesized to be primitive in Scolecopteris based on geologically younger species. Supposed primitive characters include the large synangium pedicel with fiber core, an outer-facing sporangial wall lacking differentiation or zonation, and large spores. The anatomy of the sporangium walls, pinnule morphology, and general spore type support an association with the Minor group of Scolecopteris. The new species is similar in several important features to Scolecopteris (Cyathotrachus) altus, the only other anatomically preserved fertile marattialean known from this early time, and indicates a considerably earlier origin for fertile foliage of this type.     

ON A NEW STRUCTURALLY PRESERVED ARBORESCENT LYCOPSID FRUCTIFICATION FROM THE LOWER PENNSYLVANIAN OF NORTH AMERICA

Bisporangiate lycopsid fructifications are described from petrifaction material of Pottsville (lower Pennsylvanian) age collected in eastern Kentucky. The largest specimen of Lepidostrobus schopfii sp. n. is 8.0 cm long and approximately 1.3 cm in diam; it is not complete at either apex or base. Basal megasporangia, each containing a variable number (12-29) of megaspores, and apical microsporangia are adaxially positioned on pedicels bearing reduced lateral laminae. Features of the cone axis and pattern of vascularization are described. Of particular interest is the occurrence of well-preserved endosporic megagametophytes showing archegonia and rhizoids. The new species is compared with other structurally preserved bisporangiate lycopsid fructifications of equivalent age.     

四种犬科（Canidae）动物线粒体DNA分子进化

以９种限制性内切酶分析家犬,狼,赤狐,貉共７只动物的一粒体ＤＮＡ限制性片段长度多态性（ｍｔＤＮＡＲＦＬＰ）,通过双酶解法构建各种动物的限制性内切酶图谱,用ＵＰＧ法,ＮＪ法和简略法分析这些动物之间的遗传关系。结果表明,１．犬的个体差异小,而赤弧的个体间遗传分化程度非常高;２．犬和狼的亲缘关系很近,应是同一种动物;３．在属间关系中,犬属与狐属的关系较接近,貉属是一个较早分化的独立分支。     

河北唐山下奥陶统牙形刺生物地层的新认识

本文作者在安太庠等(1983)研究过的唐山赵各庄剖面,对下奥陶统冶里组和亮甲山组较系统地采集了牙形刺样品,通过对所获牙形刺标本和安太库等(1983)所描述的牙形刺动物群仔细研究后,对包括分带和对比意见有新的认识。安太庠等(1983)把自寒武系凤山组顶部至下奥陶统亮甲山组这段地层,自下而上建立了Cordylodus proavus,Utahconus beimadaoensis-Monocostodus sevierensis,Cordylodus rotundatus-"Acodus"oneotensis,Scolopodus quadraplicatus-S.opimus,Scalpellodus tersus,Serratognathus bilobatus,S.extensus和Paraserratognathus paltodiformis等8带,其中Cordylodus proavus带为寒武系顶,Utahconus beimadaoensis-Monocostodus sevierensis至Scolopodus quadraplicatus-S.opimus等带为下奥陶统冶里组,其余则为下奥陶统亮甲山组,寒武系-奥陶系界线置于Utahconus beimadaoensis-Monocostodus sevierensis带之底。这一牙形刺序列和寒武系-奥陶系界线划分方案在国内被广泛引用至今(王志浩等,2011)。本文通过补充采集到的牙形刺标本和安太庠等(1983)报道的材料,根据一些重要分子在地层中的分布及公认的牙形刺分带原则,对安太庠等(1983)的牙形刺分带方案重新修订,自下而上修订为Cordylodus proavus,C.lindstromi,Iapetognathus jilinensis,Cordylodus angulatus,Chosonodina herfurthi-Rossodus manitouensis,Glyptoconus quadraplicatus,Scalpellodus tersus-Triangulodus aff.bifidus,Serratognathus bilobatus,S.extensus和Paraserratognathus obesus等10带,寒武系-奥陶系界线则置于Iapetognathus jilinensis带之底。根据这一修订后的牙形刺序列,寒武系顶至下奥陶统冶里组部分的牙形刺带可与国内、外相同层位的牙形刺带进行精细对比,而亮甲山组的牙形刺虽有明显的地方性特点,但除其顶部因更具地方性而不能直接对比外,其中下部仍可与华南区下奥陶统红花园组相对比。     

ON SOME SPECIES OF GLOBULAROSCHONGASTIA AND TROMBICULA

1. Globularoschongastia rattihaikonga sp. nov. (Figs. 1-13). When alive, both body and eyes are red in color. Well-fed specimensmeasure 493 μlong and 273 μwide. Gnathosoma measures 91 μlong and85 μ wide. Gnathosoma or capitulum. Gnathosoma large. Chelicera punctate dorso-proximally and with a tricuspid cap distally. Galeal setae nude but veryoccasionally with one tiny branch. Palpal segments: setae on femur andgenu plumose; those on dorsal and ventral side of tibia plumose, while thelateral ones nude but occasionally with 1-2 branches; on tarsus are one     

RETICULATE THICKENINGS IN SOME SPECIES OF JUGLANS

Reticulate thickenings in Juglans nigra, J. major, J. microcarpa, and J. californica (including J. hindsii) appear, under the transmitted light microscope, to be a cluster of very large or “gash-like” vessel-ray pits. The use of scanning electron microscopy shows that these so-called pits are thickenings on the inside wall of the vessel.