江西志留纪山口中华盔甲鱼的再描述（英文）

基于对江西省修水县志留系西坑组发现的11个新标本的观察,对存在争议的山口中华盔甲鱼(Sinogaleaspis shankouensis)进行了重新描述。深入的形态学研究表明,山口中华盔甲鱼的侧线感觉管系统展示出基干盔甲鱼类、真盔甲鱼目、多鳃鱼目和华南鱼目等多个类群的镶嵌特征。山口中华盔甲鱼的侧线感觉管系统由4条纵行干管和6条横向联络管相互交叉在头甲背面形成格栅状分布,可能反映了脊椎动物的祖先状态。山口中华盔甲鱼在动物群上属于中华盔甲鱼–修水鱼组合或茅山组合,该组合可能代表了盔甲鱼类在志留纪兰多维列世特里奇期的第一次适应辐射。江西修水西坑组古沉积环境指示了一种低盐度半咸水的近海环境,可能是由于大量淡水从附近河流涌入导致盐度降低,而含鱼层位灰绿色泥质粉砂岩中含有的大量泥砾则指示鱼化石经历了短距离的河流搬运。因此,该生物群可能生活在埋藏区域上游的淡水河流里。     

记一新的无颌类化石兼论多鳃鱼类的分类地位

本文记述了云南宜良早泥盆世一新的无颌类化石,高棘四营鱼,新属、新种 (Siyingiu altuspinosa gen.et sp.nov)。在讨论中主要涉及鼻垂体凹的构造和多鳃鱼类的分类地位。笔者认为,多鳃鱼类和盔甲鱼类的鼻垂体孔位于鼻垂体凹的软骨成分中,它没有吸水的功能,只具感觉的功能。多鳃鱼目不应置于鳍甲鱼纲,而应放在头甲鱼纲的盔甲鱼亚纲中。在盔甲鱼亚纲中,南盘鱼不是接近于盔甲鱼目而是接近于多鳃鱼目。     

云南曲靖下泥盆统盔甲鱼类(无颌类)的新发现（英文）

描述了云南曲靖早泥盆世西山村组盔甲鱼类(无颌类)的新发现,包括一新属、新种——惠清驼背鱼(Altigibbaspis huiqingae gen.et sp.nov.),一件属种未定的多鳃鱼科标本,以及张氏真盔甲鱼(Eugaleaspis changi)和小眼南盘鱼(Nanpanaspis microculus)的新材料。驼背鱼在很多方面与多鳃鱼都非常相似,但头甲背面具一特征性的驼背状隆起,其上有一刀刃状的中背脊。中背脊和中背棘在盔甲鱼类里的形态分异度表明,它们除了能够提供游泳方向稳定性外,可能还衍生出了一些附加的功能,例如直立高耸的中背棘能使盔甲鱼在捕食者眼里具有了恐吓性,刀刃状的中背脊可能也起到一些防御的作用。南盘鱼头甲侧缘具有两对非常奇特的侧向延伸的突起;通过对这两对侧突同源性的比较,讨论了南盘鱼的潜在系统分类位置。鉴于南盘鱼奇特的形态,以及它在华南鱼目中相对较早的出现时代,建议暂时把南盘鱼放到一个单属科南盘鱼科,代表了华南鱼目早期分出来的一个支系。     

云南曲靖下泥盆统西山村组四营鱼属(Siyingia)一新种(英文)

主要采用形态学与比较解剖学的方法,对采自云南曲靖地区下泥盆统西山村组中的1件盔甲鱼类标本进行了详细的形态学研究,建立了多鳃鱼类四营鱼属1新种:宽棘四营鱼(Siyingia perlatuspinosa sp.nov.),并据此修订了四营鱼属的特征。在此基础上,应用分支系统学对多鳃鱼类属一级的系统发育关系进行了重新分析与探讨,确定了四营鱼在多鳃鱼类中的系统发育位置。系统发育分析结果显示,四营鱼(Siyingia)与多鳃鱼(Polybranchiaspis)亲缘关系最近,二者形成了一个单系类群,与宽甲鱼(Laxaspis)+坝鱼(Damaspis)组成的单系类群互为姊妹群。宽棘四营鱼的发现不仅拓宽了四营鱼在华南的时空分布范围,而且丰富了多鳃鱼类的多样性,并为多鳃鱼类的深入研究提供了可靠的化石新证据。     

云南早泥盆世一流线型盔甲鱼及其分类学与古生态学意义(英文)

记述了云南昭通早泥盆世布拉格期坡松冲组华南鱼目一新属、新种——剑裂甲鱼(Rhegmaspis xiphoidea gen.et sp.nov.)。新属的主要特征是:具有鱼雷形头甲,细长吻突,眶孔位于头甲腹侧位,鳃穴向头甲腹面弯曲,角、内角和腹环丢失。鉴于以上特征,新属被归到了包括鸭吻鱼和乌蒙山鱼在内的鸭吻鱼科。根据新材料提供的信息,修订了鸭吻鱼科,包括鸭吻鱼和乌蒙山鱼的鳃穴、腹环、角、内角等特征。裂甲鱼属是该地区发现的第一个具有流线形体型的盔甲鱼类,指示了该地区一些盔甲鱼类可能开始了一种营上底栖的生活方式,具有更加主动的取食行为。新属的发现不仅丰富了该地区华南鱼目的多样性,而且提供了盔甲鱼类在早泥盆世布拉格期通过占据新的生态位而发生的最后一次辐射演化的证据。     

云南发现新的全骨鱼类化石

正据英国皇家学会《生物学报》报道,中国科学院古脊椎动物与古人类研究所、浙江自然博物馆和芝加哥大学组成的研究小组在云南省罗平县三叠纪地层中发现辐鳍鱼亚纲中一种新的全骨鱼类化石,命名为罗平强壮鱼(Robustichthys luopingensis)。该发现为研究全骨鱼类的早期演化和预言鱼目(Ionoscopiformes)的起源提供了关键性的证据。全骨鱼类是真骨鱼类(现生脊椎动物中最大的类群)的姐妹群,在研究辐鳍鱼亚纲新鳍鱼     

记真盔甲鱼类两新属——兼论真盔甲鱼类系统发育关系

本文记述了早泥盆世真盔甲鱼类两新属:憨鱼属(Nochelaspis)和翼角鱼属(Pterogonaspis).真盔甲鱼类是盔甲鱼类的一个单系类群,现有七属十二种,文中运用分支系统学原理对其系统发育关系进行了初步探讨.     

浙江长兴志留纪真盔甲鱼类新材料及真盔甲鱼目系统发育关系的讨论

对浙江长兴地区志留纪真盔甲鱼类的新材料进行了研究。形态学研究结果表明 ,雷曼煤山鱼 (Meishanaspislehmani)一属种成立 ,并非浙江中华盔甲鱼 (Sinogaleaspiszhejiangensis)的同物异名。在此基础上 ,运用分支系统学的原理 ,对真盔甲鱼目的系统发育关系进行了探讨 ,分析结果表明 ,中华盔甲鱼属现有的 3个种并未组成一个单系类群 ,而是一个并系类群。浙江中华盔甲鱼不能归到中华盔甲鱼属 ,建议另立一新属。     

多鳃鱼类一新属及该类鱼感觉沟系统的变异

本文记述了云南曲靖早泥盆世翠峰山组西山村段多鳃鱼类一新属种,变异坝鱼(Damaspis vartus gen.et sp.nov.)文中讨论了多鳃鱼类头甲背部感觉沟系统的基本模式,它的变化和变异。从这个基本模式出发笔者认为三岔鱼科和多鳃鱼科有许多重要的特征相近,似乎应把三岔鱼科和多鳃鱼科隶属于同一个高一级的分类单元即多鳃鱼目,而不应把三岔鱼科置于“华南鱼目”。“华南鱼目”是根据了解还不多的华南鱼属建立的,有些勉强,建议暂不采用。文中首次指出多鳃鱼类的感觉沟系统存在变异现象并认为在确立新类型时,变异是应该考虑的一个重要因素。     

云南罗平发现世界上最早的铰齿鱼类新属种：优美玉带鱼

<正>铰齿鱼类包括拱鱼目、半椎鱼目和鳞骨鱼目。生活在中北美和古巴淡水环境的雀鳝是铰齿鱼类鳞骨鱼目的现生代表,被称为活化石,为新鳍鱼类的研究提供了重要信息。新鳍鱼类是辐鳍鱼亚纲最大的演化支系,几乎分布于地球上各种水环境。除了多鳍鱼和鲟鱼,其他所有的现生辐鳍鱼类都属于新鳍鱼类。《古脊椎动物学报》最新报道了中国科学院古脊椎动物与古人类研究所徐光辉研究团队在我国云南罗平发现了两亿四千万年前一种新的铰齿鱼类:优美玉带鱼。优美玉带鱼,可归入     

Phylogenetic relationships of galeaspids (Agnatha)

We present the first parsimony analysis of the agnathan subclass Galeaspida based on the analysis of 53 morphological characters.Three most parsimonious cladograms (126 steps in length;CI=0.508;RI=0.801)were discovered.An amended classification of the Galeaspida is proposed corresponding to the present analysis.Our results suggest that hanyangaspids,xiushuiaspids and dayongaspids from the Llandovery-Wenlock of Silurian are basal galeaspids.Within the remaining galeaspids,three major monophyletic groups (the Eugaleaspidiformes,the Polybranchiaspidiformes and the Huananaspidiformes)are well supported.It is shown that the dorsal fenestrae of the headshield evolved twice within the Galeaspida,one in the polybranchiaspidiform lineage,and the other in the huananaspidiform lineage (nested within the Huananaspidae).The chronological distribution of galeaspids highlights two radiations of the group,one for basal galeaspids and eugaleaspids in the Telychian (Llandovery)of Silurian,and the other for polybranchiaspidiforms and huananaspidiforms in the Lochkovian of Early Devonian.     

Phylogenetic relationships of galeaspids (Agnatha)

We present the first parsimony analysis of the agnathan subclass Galeaspida based on the analysis of 53 morphological characters. Three most parsimonious cladograms (126 steps in length; CI = 0.508; RI = 0.801) were discovered. An amended classification of the Galeaspida is proposed corresponding to the present analysis. Our results suggest that hanyangaspids, xiushuiaspids and day on-gaspids from the Llandovery-Wenlock of Silurian are basal galeaspids. Within the remaining galeaspids, three major monophyletic groups (the Eugaleaspidiformes, the Polybranchiaspidiformes and the Huananaspidiformes) are well supported. It is shown that the dorsal fenestrae of the headshield evolved twice within the Galeaspida, one in the polybranchiaspidiform lineage, and the other in the huananaspidiform lineage (nested within the Huananaspidae). The chronological distribution of galeaspids highlights two radiations of the group, one for basal galeaspids and eugaleaspids in the Telychian (Llandovery) of Silurian, and the other for polybranchiaspidiforms and huananaspidiforms in the Lochkovian of Early Devonian. Selected from Vertebrata PalAsiatica, 2006, 44 (1): 1–27     

盔甲鱼类的侧线系统

本文对盔甲鱼类的侧线系统作了系统的描述;盔甲鱼类与异甲鱼类、骨甲鱼类和七鳃鳗在侧线系统方面可作相近的对比;盔甲鱼类众多的横行感觉管暗示在原始脊椎动物里,横行感觉管按节排列、由前而后分布整个头区;在盔甲鱼类中侧线系统存在多鳃鱼型和真盔甲鱼型,两者的分化至迟在早志留世已经完成.     

浙江安吉志留纪真盔甲鱼类一新属

记述了浙江安吉地区志留纪真盔甲鱼类一新属——安吉鱼(新属)(Anjiaspis gen.nov.)。新属的主要特征是:中背孔呈纵长的滴水形,前端稍尖,距离头甲吻缘较远,后端圆钝,明显位于两眶孔前缘连线之前;眶孔较小,位置十分靠近头甲中线,并距离头甲后缘较近,眶孔前区长于眶孔后区;松果孔大致位于两眶孔中心连线上;感觉管系统大致呈格栅状分布,可见4条纵行干管及联络它们的横行管,横行管由侧横管和中横联络管组成,其数目均比较多;鳃囊6对,纹饰为均匀分布的细小粒状瘤点。在此基础上运用分支系统学的方法对其系统位置进行了探讨,结果表明,新属代表了真盔甲鱼类的最原始类型。     

The circulatory system of Galeaspida (Vertebrata; stem-Gnathostomata) revealed by synchrotron X-ray tomographic microscopy

Micro-CT provides a means of nondestructively investigating the internal structure of organisms with high spatial resolution and it has been applied to address a number of palaeontological problems that would be undesirable by destructive means. This approach has been applied successfully to characterize the cranial anatomy of Shuyu, a 428 million-year-old galeaspid (jawless stem-gnathostome) from the Silurian of Changxing, Zhejiang Province, China. Here, we use the synchrotron X-ray tomographic microscopy (SRXTM) to further describe the circulatory system of the head of Shuyu. Our results indicate that the circulatory system of galeaspids exhibits a mosaic of primitive vertebrate and derived gnathostome characters, including a number of derived gnathostome characters that are absent from osteostracans — the group conventionally interpreted as the sister lineage of jawed vertebrates. Our study provides a rich source of information that can be used to infer and reconstruct the early evolutionary history of the vertebrate cardiovascular system.     

Discriminating signal from noise in the fossil record of early vertebrates reveals cryptic evolutionary history

The fossil record of early vertebrates has been influential in elucidating the evolutionary assembly of the gnathostome bodyplan. Understanding of the timing and tempo of vertebrate innovations remains, however, mired in a literal reading of the fossil record. Early jawless vertebrates (ostracoderms) exhibit restriction to shallow-water environments. The distribution of their stratigraphic occurrences therefore reflects not only flux in diversity, but also secular variation in facies representation of the rock record. Using stratigraphic, phylogenetic and palaeoenvironmental data, we assessed the veracity of the fossil records of the jawless relatives of jawed vertebrates (Osteostraci, Galeaspida, Thelodonti, Heterostraci). Non-random models of fossil recovery potential using Palaeozoic sea-level changes were used to calculate confidence intervals of clade origins. These intervals extend the timescale for possible origins into the Upper Ordovician; these estimates ameliorate the long ghost lineages inferred for Osteostraci, Galeaspida and Heterostraci, given their known stratigraphic occurrences and stem–gnathostome phylogeny. Diversity changes through the Silurian and Devonian were found to lie within the expected limits predicted from estimates of fossil record quality indicating that it is geological, rather than biological factors, that are responsible for shifts in diversity. Environmental restriction also appears to belie ostracoderm extinction and demise rather than competition with jawed vertebrates.     

新疆柯坪志留纪兰多维列世无颌类化石

描述了新疆柯坪县铁力克瓦铁村附近志留纪兰多维列世塔塔埃尔塔格组无颌类盔甲鱼亚纲的 3个新属、新种。无颌类化石面貌表明 ,塔塔埃尔塔格组大致与长江中下游的溶溪组相当 ,其时代为兰多维列世的特列奇期 (Telychian)。塔塔埃尔塔格组时代的更正 ,使得塔里木盆地和扬子区中古生代地层可直接进行对比。同时 ,两地鱼群性质和沉积环境的相似性证明 ,在志留纪时它们可能彼此相距很近。     

盔甲鱼类Antiquisagittaspis cornuta(新属、新种)在广西六景下泥盆统的发现

本文记述了盔甲鱼类三岔鱼科 (sanchaspidae) —新属 Antiquisagittaspis 并对含鱼层时代作了对比;同时对中背孔和盔甲鱼类的生活环境作了评述.     

Functional assessment of morphological homoplasy in stem-gnathostomes

Osteostraci and Galeaspida are stem-gnathostomes, occupying a key phylogenetic position for resolving the nature of the jawless ancestor from which jawed vertebrates evolved more than 400 million years ago. Both groups are characterized by the presence of rigid headshields that share a number of common morphological traits, in some cases hindering the resolution of their interrelationships and the exact nature of their affinities with jawed vertebrates. Here, we explore the morphological and functional diversity of osteostracan and galeaspid headshields using geometric morphometrics and computational fluid dynamics to constrain the factors that promoted the evolution of their similar morphologies and informing on the ecological scenario under which jawed vertebrates emerged. Phylomorphospace, Mantel analysis and Stayton metrics demonstrate a high degree of homoplasy. Computational fluid dynamics reveals similar hydrodynamic performance among morphologically convergent species, indicating the independent acquisition of the same morphofunctional traits and, potentially, equivalent lifestyles. These results confirm that a number of the characters typically used to infer the evolutionary relationships among galeaspids, osteostracans and jawed vertebrates are convergent in nature, potentially obscuring understanding of the assembly of the gnathostome bodyplan. Ultimately, our results reveal that while the jawless relatives of the earliest jawed vertebrates were ecologically diverse, widespread convergence on the same hydrodynamic adaptations suggests they had reached the limits of their potential ecological diversity—overcome by jawed vertebrates and their later innovations.     

Phylogeny of the Pteraspidiformes (Heterostraci), Silurian–Devonian jawless vertebrates

The Pteraspidiformes are an order of armoured agnathans of Silurian and Devonian age composed of five families: the Anchipteraspididae, Protopteraspididae, Pteraspididae, Protaspididae and Psammosteidae. Relationships within the order are poorly known and although past attempts have been made to represent the state of knowledge in this area none have attempted a rigorous computer-based analysis. Here we present the results of the cladistic analysis on a matrix comprising 25(+1) taxa and 59 characters using W inclada . The first analysis was run without any representative of the Psammosteidae and supports the presence of five groups within the order although one, the 'Protopteraspididae', is paraphyletic and a second, the Gigantaspididae, is newly recognized. In a second analysis the addition of the psammosteid Drepanaspis gemuendenensis results in a better resolved tree in which the basal family, the Anchipteraspididae, are clearly monophyletic and in which the Psammosteidae, as represented by Drepanaspis , is the next less inclusive. This is contrary to the previous view that the psammosteids were an advanced clade within the Pteraspidiformes.