含铁石英岩的磁铁矿形态特征

含铁石英岩及其有关富矿的现貌,在某种程度上,反映了它们漫长而复杂的发展阶段。运用研究个体发育的方法,可以揭示矿物个体和构造上相关联的集合体的形成和矿物连晶类型特征、矿物形成顺序、矿物生成和变化特征。这些矿物是成矿作用不同阶段的变形和反应的复杂关系的产物。含铁石英岩的特征是微细层理。磁铁矿和赤铁矿的个体和集合体粒径的增加与层理有关,从非矿层经混合层向矿层过渡时,个体和集合体粒径是增加的,而石英则是减小的(见表)。     

许氏创孔海百合Traumatocrinus hsui的形态定量分析和个体发育过程

Traumatocrinus hsu Mu, 1949是关岭生物群的重要组成成员,以数量众多、保存精美、营假浮游生活闻名于世。笔者等通过对5件群体保存标本中的127个大小不同个体的系统描述和形态定量分析,认为T. hsui萼部与整个冠部存在异速生长的特征,个体发育过程中腕的级数和数目逐渐增加;T. hsui的个体发育可分为3个时期6个阶段,即幼年期（Ⅰ、Ⅱ）、少年期（Ⅰ、Ⅱ、Ⅲ）、成年期;幼年期：个体较小,冠高小于26 mm,腕分枝至4级;少年期：个体中等,冠高26～130 mm,腕分枝至7级;成年期：个体较大,冠高大于130 mm,腕分枝至8级。前人在关岭生物群中研究命名的Traumatocrinus hsui enormis Mu, 1949,Traumatocrinus kueichouensis Mu, 1949,Traumatocrinus uniformis Mu, 1949,Traumatocrinus sp. Mu, 1949,Traumatocrinus guanlingensis Yu et al., 2000和Traumatocrinus xinpuensis Wang et al., 2002等均为T. hsui的同种异名,其命名标本为个体发育的不同阶段或局部特征。     

许氏创孔海百合Traumatocrinus hsui的形态定量分析和个体发育过程

Traumatocrinus hsui Mu, 1949是关岭生物群的重要组成成员,以数量众多、保存精美、营假浮游生活闻名于世。笔者等通过对5件群体保存标本中的127个大小不同个体的系统描述和形态定量分析,认为T. hsui萼部与整个冠部存在异速生长的特征,个体发育过程中腕的级数和数目逐渐增加;T. hsui的个体发育可分为3个时期6个阶段,即幼年期（Ⅰ、Ⅱ）、少年期（Ⅰ、Ⅱ、Ⅲ）、成年期;幼年期：个体较小,冠高小于26 mm,腕分枝至4级;少年期：个体中等,冠高26～130 mm,腕分枝至7级;成年期：个体较大,冠高大于130 mm,腕分枝至8级。前人在关岭生物群中研究命名的Traumatocrinus hsui enormis Mu, 1949,Traumatocrinus kueichouensis Mu, 1949,Traumatocrinus uniformis Mu, 1949,Traumatocrinus sp. Mu, 1949,Traumatocrinus guanlingensis Yu et al., 2000和Traumatocrinus xinpuensis Wang et al., 2002等均为T. hsui的同种异名,其命名标本为个体发育的不同阶段或局部特征。     

高肌虫的个体发育及性双形特征

行蜕壳式增长的节肢动物个体发育及性双形特征的研究必须建立在其化石种群结构的恢复之上。简单的数理统计是揭示其种群结构特征的钥匙:鉴别是否属正常化石种群,确定蜕壳期数,解释早期幼壳高死亡率与其化石低保存牢的统一。高肌虫个体发育常表现为六至七期明显的蜕壳阶段,蜕壳期间壳体增长率常在性成熟期有显著的减小趋势。物种的正确鉴定及性双形特征的辨识也只有通过个体发育研究才能得到合理的解决;物种在个体发育过程中表现出来的性伏变化,为研究谱系的演化趋向提供重要依据。这种数理统计方法无疑对三叶虫、介形虫等其他节肢动物的个体发育及性双形研究也完全适用。     

孙氏新铺龙（爬行纲：海龙目）一新幼年个体研究

新铺龙是产于我国西南地区的海龙目的一个属,最早发现于贵州省关岭晚三叠世卡尼期小凹组地层。虽然新铺龙材料众多,但其未成年个体骨骼学特征及个体发育模式并未被详细地记述。本文报道了一个保存完好的孙氏新铺龙未成年标本,是目前发现最小的完整的孙氏新铺龙个体,标本产自贵州省关岭县新铺乡。依据其体长小于正型标本的一半,头骨长度和躯干比值大,头骨骨缝清晰等特征,判断该标本为孙氏新铺龙的幼年个体。新标本补充了孙氏新铺龙幼年个体的形态学信息,如上颞骨内侧突短于外侧突,翼骨无牙齿发育,神经弓与椎体未融合,尺骨两端微凸,五边形坐骨等。此外,结合已发表的新铺龙标本数据进行统计分析发现,该物种吻部相对头部呈负异速生长,证明了吻部占头骨比例的大小属于新铺龙种内个体发育差异,而并非之前所认为的新铺龙种间差异。     

孙氏新铺龙（爬行纲：海龙目一新幼年个体研究

新铺龙是产于我国西南地区的海龙目的一个属,最早发现于贵州省关岭晚三叠世卡尼期小凹组地层。虽然新铺龙材料众多,但其未成年个体骨骼学特征及个体发育模式并未被详细地记述。笔者等报道了一个保存完好的孙氏新铺龙未成年标本,是目前发现最小的完整的孙氏新铺龙个体,标本产自贵州省关岭县新铺乡。依据其体长小于正型标本的一半,头骨长度和躯干比值大,头骨骨缝清晰等特征,判断该标本为孙氏新铺龙的幼年个体。新标本补充了孙氏新铺龙幼年个体的形态学信息,如上颞骨内侧突短于外侧突,翼骨无牙齿发育,神经弓与椎体未融合,尺骨两端微凸,五边形坐骨等。此外,结合已发表的新铺龙标本数据进行统计分析发现,该物种吻部相对头部呈负异速生长,证明了吻部占头骨比例的大小属于新铺龙种内个体发育差异,而并非之前所认为的新铺龙种间差异。     

似犬齿珊瑚属Caninophyllum Lewis，1929（四射珊瑚）两个种个体系统发育特征研究

四射珊瑚似犬齿珊瑚属Caninophyllum Lewis,1929广泛发育于欧洲、亚洲和北美地区石炭纪至早二叠世,以成年期主隔壁缩短且不发育轴部构造为特征,由于该属一些种的主、对隔壁特征及轴部构造在成年期特征与原始定义不符,导致关于Caninophyllum Lewis,1929定义存在分歧。根据准噶尔盆地东北缘上石炭统石钱滩组发现的保存较完整的Caninophyllum shuangjingziense Zeng,1983与Caninophyllum yui Wang,1989个体系统发育特征,并结合模式种及原始描述,认为Caninophyllum在早期个体发育阶段,原生隔壁（轴连隔壁）便分离为主隔壁与对隔壁,成年期主隔壁整体呈现缩短趋势,对隔壁与对部其余一级隔壁等长,轴部构造不发育。     

莱得利基虫及其数新种

莱得利基虫(Redlichia)一属为下寒武纪最重要三叶虫之一,此属在地理上分布之广以及其在地质史上出现时间之长,同时代其他化石均无出其右。几十年来经中外学者各方面之研究,知其在地理上分布似远出乎一般意料之外,其地层上垂直分布似亦与其演化程序有重大关系。至於本属之个体发育,尤饶兴味,由个体发育观察,不     

江南—雪峰隆起构造动力学与海相油气成藏演化

研究讨论了我国南方江南-雪峰隆起这一独特的大地构造单元在板块构造阶段和大陆构造阶段的发育背景及其构造动力学。在此基础上阐述了江南-雪峰隆起及其周缘的海相油气聚集、破坏的特征和背景(构造动力学框架下),研究试图揭示隆起及其周缘的海相油气聚集和破坏与隆起形成演化及其动力学之间在时间和空间上的成因联系。最后讨论了隆起在板块构造与大陆构造不同阶段演化和动力学问题、板块构造与大陆构造观点对隆起及其周缘成藏物质基础制约的不同认识、以及隆起及其周缘构造演化与海相油气成藏演化的关系。     

胡氏贵州龙的个体发育研究

本文通过对78件胡氏贵州龙标本的特征性状进行分析与测量,并对选定的10组特征性状比率关系进行统计分析,认为胡氏贵州龙在生长发育过程中头、眼、肱骨、股骨与身体其他部分有明显的异速生长特征,并根据这些特征将胡氏贵州龙的个体发育分为：胚胎期,幼年期,少年期,青年期及成年期五个阶段.除胚胎期外各个阶段的特征明显,可以通过定量的方法加以区别.     

凯里生物群中始海百合类形态功能、生态及埋藏特征初探

贵州剑河八郎中寒武世凯里生物群中始海百合十分丰富,化石标本多达1万多件,分属长茎型的卢氏中国始海百合（Sinoeocrinus Zhao, Huang et Gong,1994）及短茎型的球形中国始海百合（Sinoeocrinus globus Zhao et al, 1999）。它们均具有腕枝、萼、茎及吸盘,少数标本见有肛锥。幼年体缝孔不发育,成年体具有较发育的缝孔。大部分个体为单体生活。短茎型的萼呈球形,茎短,吸盘大,常固着在腕足动物外壳及三叶虫背壳碎片上。长茎的萼呈长椭圆球形茎长,吸盘小,常固着在砂泥质海底。两个种的腕肢也有差别,长茎的直长,短茎的旋转生长,显示两个种的形态差别及多样性。由于始海百合死亡后迅速被掩埋,80%以上的个体保存完整。化石大部分保存无定向性,显示静水环境,海底紊流很少,不仅显示原地埋藏特征,也为凯里生物群是原地埋藏提供了重要证据。     

新疆柯坪巴立克立克组腕足动物群

报道和首次描述巴立克立克组腕足动物共30属39种,其中1新属7新种.该动物群具有石炭、二叠系过渡的性质,时代属于阿舍尔末期至萨克马尔最初期.Choristites qiudaisaiensis-Costifrina indicus 带分为 Postamartinia granulipwa-Rugivestis kutorgae 上亚带和 Costiferina punilus-Meckella hemiplicata 下亚带.下亚带属于阿舍尔末期,上亚带属于萨克马尔最初期,石炭、二叠乐界线置于下、下亚带之间,该动物群生物地理区系属古地中海大区,次级区系特征不明显,具混合性质。     

辽东太子河流域石炭系下部红层腕足动物群研究

早石炭世晚期至晚石炭世早期,太子河流域发育了一套红层沉积,泥岩中含有丰富的腕足动物化石,共计２１属３９种。系统分析了腕足动物群性质;结合围岩和地球化学特征等,识别出ＬｉｎｏｐｒｏｄｕｃｔｕｓＯｖａｔｉａ群落,它生活在与广海相连的浅水海湾低潮线附近地带;对同期腕足动物群进行了比较和讨论,提出当时研究区属于天山—辽吉腕足动物生物地理分区的观点。     

新疆阿克苏地区康克林组腕足动物群

记述康克林组腕足动物４５属６４种，描述９个新种。其时代为阿舍尔期。古生物地理区划属特提斯大区，欧洲－华夏区。     

Recruitment, survivorship, and age structure of a New York ribbed mussel population (Geukensia demissa) in relation to shore level—a nine year study

Age structure, recruitment, and survivorship of a Jamaica Bay, New York ribbed mussel (Geukensia demissa) population were studied over nine years at two shore elevations. Mussels were collected in November (following seasonal growth and recruitment) and March (to assay over-winter mortality). Larval recruits (0-class) averaged 55% of the population at the marsh edge compared with <9% at the higher elevation (6 m upshore). High larval settlement at the edge apparently depletes the larval supply available for settlement within the marsh interior. At the edge, the population generally contained 7 monotonically decreasing age classes compared to 15–20 age classes at the interior site. At the interior site, most 0-class mussels may not directly settle into existing mussel aggregations, but instead immigrate over a period of two years following settlement. The linear survivorship curve at the edge reflects 40–50% mortality every year. Over-winter mortality is sensitive to winter ice conditions. Simulations of reproductive output based on survivorship and fertility data combined suggest that mussel cohorts living in the marsh may approach the life time reproductive output of marsh edge mussels after about 15 years, a life span which is not uncommon at higher shore levels.     

Pink shrimp,Farfantepenaeus duorarum,recruitment variability as an indicator of Florida Bay dynamics

Florida Bay exhibits highly dynamic hydrographic regimes that influence variability in the retention, survivorship, and migration of pink shrimp,Farfantepenaeus duorarum, larvae and juveniles. Florida Bay is the nursery habitat for pink shrimp and since a large fishery is based on the adult population in the Dry Tortugas region, Florida Bay plays a fundamental role in the health of the pink shrimp fishery in South Florida. Conversely, the level of shrimp recruitment to the fishery can act as an indicator of the health of Florida Bay integrating multiple biological, physical, and environmental variables. We examined 372 mo of data on commercial landings of pink shrimp to estimate monthly recruitment. We found recruitment occurs throughout the year, there are one or more seasonal peaks, and the magnitude and monthly position of the peaks changed through decades. These changes may be explained by a varying spawning population producing different levels of eggs, by environmental changes in the nursery grounds that modulate a nearly constant supply of eggs, or a combination of these. Recruitment estimates and the residuals about stock-recruitment relationships were compared over three decades (1965–1995) in terms of annual and monthly trends and average patterns. Significant differences found between the decades could be due to ecological changes in Florida Bay, specifically to loss of recruitment peaks, with an associated overall decline in pink shrimp recruitment. For the lates years of the study, recruitment and residuals about the stock-recruitment curve are increasing, which may indicate an improvement in Florida Bay as a nursery ground for pink shrimp, and thus as habitat for other organisms as well.     

The influence of introduced European green crabs (<Emphasis Type="Italic">Carcinus maenas</Emphasis>) on habitat selection by juvenile native blue crabs (<Emphasis Type="Italic">Portunus pelagicus</Emphasis>)

The European green crab (Carcinus maenas) is a highly successful marine invader, having established populations in a number of areas outside its natural range in the last 100 years. In South Australia,C. maenas can be abundant on intertidal mud flats, which are used by juveniles of the native blue swimmer crab (Portunus pelagicus) and could have the potential to cause substantial negative effects on this species. The influence of adult blue and green crabs on habitat selection by juvenile blue crabs was tested to determine if they responded to both predators in a similar fashion. The presence of predators did not influence habitat selection by juvenile blue crabs in either laboratory or field experiments, but juvenile behavior in the selected habitat did differ between the two adult species. Many more crabs buried themselves beneath the substrate when adult conspecifics were present than when adult green crabs were present. Burying in the presence of adult green crabs was no more frequent than when predators were absent. It remains to be determined if this makes juvenile blue crabs more vulnerable to predation by green crabs than by adults of their own species, or if the difference in response is because green crabs pose a different or lesser threat.     

Pachycephalosaurs (Dinosauria: Ornithischia) from the Upper Cretaceous (upper Campanian) of New Mexico: A reassessment of Stegoceras novomexicanum

Pachycephalosaurs, a group of ornithischian dinosaurs with distinctive cranial ornamentation and skull domes, underwent dramatic changes in cranial morphology during ontogeny. This has caused debate about whether some specimens belong to juveniles or adults, which impacts studies of pachycephalosaur phylogeny and evolution. One such debate concerns a small skull roof specimen from the Campanian (Upper Cretaceous) of New Mexico, NMMNH P-33898, which was originally described as an indeterminate juvenile but later regarded as a mature adult and erected as the holotype of a new small-bodied species, Stegoceras novomexicanum. We restudied NMMNH P-33898 using computed tomography scanning, morphometric and phylogenetic analyses, and comparisons to growth series of other pachycephalosaurs (Stegoceras validum, Pachycephalosaurus wyomingensis). We conclude that two purported paratype specimens of Stegoceras novomexicanum cannot be referred to the same taxon as the holotype, that the holotype and controversial paratypes all belong to immature specimens and not aberrant small-bodied adults, but that current evidence cannot clearly determine whether NMMNH P-33898 is a juvenile belonging to its own diagnostic species (S. novomexicanum) or is a juvenile of Stegoceras validum, Sphaerotholus goodwini, or another known taxon. We review the pachycephalosaur record of New Mexico and demonstrate that pachycephalosaurs were important components of dinosaur faunas in the southern part of Western North America during the ∼15 million years before the end-Cretaceous extinction, just as they were in roughly contemporaneous northern localities.     

华南上泥盆统法门阶哲杜斯贝动物群的埋藏学和居群动力学特征*

哲杜斯贝是一种以高丰度和低物种分异度为显著特征、在全球广泛独立分布的小嘴贝类。笔者对华南台地相和台间盆地相5个含哲杜斯贝类上泥盆统剖面进行沉积环境和埋藏特征研究,确定华南哲杜斯贝类的原生沉积环境为台地的正常浅水,这与美国和摩洛哥生长在冷泉环境中的哲杜斯贝不同,表明其既可在浅海环境中生长,也可以在冷泉环境中生长,具有较强的生态可塑性。台地相(原地埋藏)的3个哲杜斯贝种群具有以下特征:(1)均呈现出壳体呈层状紧密堆积、集群生长特点,丰度极高,并且有相当数量的个体呈现出由于拥挤生长而导致的壳体生长畸形现象;(2)缺乏其他底栖后生生物,显示了极低的生物多样性;(3)壳体大小—频率分布和生存曲线揭示了3个哲杜斯贝种群都具有非常低的幼年期死亡率特点,同时同一介壳层内哲杜斯贝个体大小均一,表明绝大多数的个体能够达到或接近自然寿命后死亡。上述证据表明,哲杜斯贝具有密集群居生活的习性,其生活在一个独特的、不适合其他后生底栖生物生存的环境。