中国低等四脚类化石属的统计

最近编辑中国脊椎动物化石手册,有机会对我国已记述的低等四脚类化石属进行了统计。这一数字不一定完全无误:1)因有很多新属有待发表未能包括进来;2)有些门类尚未经过细的研究和订正,自然可能包括了少数同物异名的属,但总的说来统计的数字基本上是可靠的。最早而在古脊椎动物上最重要的两栖类是原始的迷齿类。但这一类化石,在我国至今发现得很少,仅在三叠纪地层中有少数迷齿类。     

李氏乌鲁木齐兽及中国的兽头类的故事

正背景:兽头类是二叠、三叠纪的一类兽孔类,与我们哺乳动物所在的犬齿兽类亲缘关系很近。它们在地球上只生存了不到三千万年,虽然躲过了二叠纪末期(大约2.5亿年前)那次大浩劫,却在三叠纪中期灭绝了。这类动物的化石早在一百多年前就在南非发现了,它们与二齿兽类、犬齿兽类等化石共同产出。目前这类化石种类、数量最丰富的也是在南非。     

俄罗斯珍稀的三叠纪两栖动物化石被窃

据国际古生物协会核心期刊Lethaia 1992第25卷报道,1992年3月19日夜,俄国科学院古生物博物馆被盗,共丢失三叠纪迷齿类两栖动物化石头盖骨15个,警方已开始进行调查。这些标本为A.P.Bystrow和I.A.Elremov以及S.N.Getmanov描述过的模式标本,其中Benthosuchua sushkni和B.bysirovi两块标本更是珍贵的全型标本。它们均以保存精美而被视为稀世瑰宝。该动物是一类原始的,具有尾和迷齿,头骨构造坚固的早期两栖类动物,最早出现于晚泥盆世,距今约3亿多年,体长约1米,头骨长约20厘米。身体表面具细小的鳞片,身体后部拖一条鱼形的尾鳍。头骨结构、牙齿的特征、脊椎形态等与总鳍鱼很相似,但它有四肢,脊椎上长出了关节突。A.P.Bystrow和l.A.Elremov,1940年在他们的文章中指出:Benthosuchua属及其分子具一脊柱的新块锥结构的发现,揭     

中国颌兽(犬齿兽类爬行动物)的补充研究

到目前为止,在我国陆相三叠纪地层里,完美中国颌兽是非三列齿类犬齿类的唯一代表,首次报道时曾被鉴定为犬鳄科 (Cynosuchidae). 本文记载了该头骨的牙齿、颌关节等特征,证明应归宽齿犬齿兽类的 Trirachodontinae.     

美国石化森林国家公园记行

<正>2018年的国际古脊椎动物会议在美国新墨西哥州阿尔伯克基举办。新墨西哥及邻区中生代地层出露广泛,发现过很多鼎鼎大名的爬行动物化石,包括三叠纪的植龙类以及三叠纪到白垩纪的多种恐龙类。阿尔伯克基有西班牙风情、印     

安徽古新世钝脚类

1977年,本文作者曾报导安徽潜山杨小屋发现的一具完整的古脊齿兽骨骼(黄学诗,1977)。在此之前这类动物的完整材料一直未被找到过。尽管颅后骨骼在钝脚类科一级的分类中有着重要意义,然而该文受篇幅的限制,未能详细阐述。此外,1971—1972年间,我所安徽野外队在另外三个地点采集了一些零散的钝脚类标本,至今尚未报导。本文在对这些新材料进行记述的同时,对上述古脊齿兽的骨架在分类上的意义作一些补充讨论。     

浙江和江西二叠/三叠系界线层上下的辐鳍鱼类化石与鱼类的绝灭、复苏和辐射

记述了浙江长兴县煤山剖面、江西修水县四都乡东岭剖面和信丰县铁石口镇铁石口剖面二叠/三叠系界线层上下的辐鳍鱼类6个类别的微体化石,包含2新属2新种,它们是:赵氏浙江鱼(Zhejiangichthys zhaoi gen.et sp.nov.)和小齿葆青鱼(Baoqingichthys microdontus gen.et sp.nov.)。这是包括全球二叠/三叠系界线层型剖面和点位(GSSP)在内的全球二叠/三叠系界线层上下辐鳍鱼类微体化石序列的首次报道。在总结煤山剖面已记述的鱼类大化石和微体化石资料的基础上,分析了长兴煤山剖面二叠纪末鱼类的集群绝灭。绝灭发生得很晚,持续的时间很短,规模也很大,绝灭率高达93%。讨论了华南二叠/三叠系之交大绝灭后鱼类的复苏和辐射,认为鱼类和牙形类一样都是大绝灭后在三叠纪最早复苏的类别,最早复苏的鱼类为裂齿鱼类;鱼类从绝灭期到辐射期仅用了1.3 Ma到4 Ma,从地质时间考虑,大绝灭后鱼类的复苏和辐射是相当快的。华南早三叠世以裂齿鱼类的张氏鱼(Zhangina)和软骨鱼类的弓鲛(Hybodus)为代表的组合替代了晚二叠世以古鳕类的中华扁体鱼(sinoplatysomys)和软骨鱼类的中华尖齿鲨(Sinacrodus)为代表的组合。华南晚二叠世海相地层产出的辐鳍鱼类和软骨鱼类的一些土著属与产于特提斯区三叠纪的一些属非常相近,表明华南下扬子区很可能是后来繁盛于特提斯区的三叠纪鱼类的发源地。     

四川自贡大山铺蜀龙动物群——简报Ⅴ 两栖类

本文对扁头中国短头鲵(新属新种) (Sinobrachyops placenticephalus gen. et sp. nov.) 的形态特征和分类位置进行简述.标本得自著名的恐龙化石产地——自贡大山铺,产出时代为中侏罗世.中国短头鲵是目前迷齿类中在地史上最年轻的一个属.它的发现使迷齿类在地球上生存时代的上限推移到中侏罗世.     

莫斯科古生物博物馆(续)

接下去的另一个展厅是古生代和三叠纪各门类的脊椎动物:鱼类、两栖类、爬行类和哺乳类。第一个展品柜中是通过独具特色的展品介绍苏联最古老的脊椎动物的研究历史。展品是上个世纪考察队采集的化石标本,研究人员的肖像和出版的古代脊椎动物的首批著作。展厅里陈列有古代无颌类的稀有标本,这些化石发现于波罗的海附近和俄罗斯地台北部。还有已绝灭的各种真骨鱼类的代表,其中包括总鳍鱼类——陆生脊椎动物的祖先。展品中有古两栖类——迷齿类(从前称之为坚头类)和蛙类。有个展品柜中展出一块岩石,其中保存有大量圆盘蜥——在骨骼构造上很象最古老的爬行动物的两栖类,它们生活在水中,而且象现生两栖类幼态时一样用鳃呼吸。早在石炭纪中期就出现了原始爬行动物,当时陆上的脊椎动物还只有两     

似卞氏兽(三列齿类爬行动物)新材料

本文记述了四川下沙溪庙组发现的三列齿类新材料,归入似卞氏兽属,建立—新种,自贡种.新材料首次揭示了该类动物的鼻腔构造.     

Geometric morphometrics of the skull of various murid rodents (Mammalia, Rodentia): relation of the skull shape to the trophic specialization

Presented is a brief overview of basic principles and notions of geometric morphometrics, a new approach to quantitative analysis of shape variations. This approach is applied to analysis of variation of the skull shape in the sample of 18 muroid genera belonging to the families Cricetidae, Arvicolidae and Gerbillidae. The skull shape is described by landmarks, and skulls are compared by resistant fit and superimposition methods. Under consideration is relation of skull shape to the trophic specialization, to family belonging, and to body size. Axial skull reveals more conspicuous relation to each of the factor analyzed as compared to mandible. Zygomatic region and tooth raw are most differentiable, while change of auditory bulla is of secondary effect. Transition from omnivorous through granivorous to grass-eating specialization involves the same trend in each of the family studied in the case of axial skull but not of mandible. Most dependent of trophic specialization appeared to be shape of axial skull rather then of mandible. Arvicolines are most specific in respect to the skull shape. Shape to size relation, although rather slight, also involves the same zygomatic-dental region. The results obtained indicate probably that geometric morphometrics does reveal variations in the skull shape that are free of the size effect.     

Selection in a cycling population: differential response among skeletal traits

Abstract Population density cycles influence phenotypic evolution through both density‐dependent selection during periods of high density and through enhanced genetic drift during periods of low density. We investigated the response of different phenotypic traits to the same density cycles in a population of the yellow‐necked mouse, Apodemus flavicollis, from Bia?owieza National Park in Poland. We examined nonmetric skull traits, skull and mandible size, skull and mandible shape, and transferrin allele frequencies. We found that all of the traits changed significantly over the seven‐year study period. The greatest changes in nonmetric traits and mandible size occurred during periods of increasing density, and the magnitude of changes in skull and mandible shape was correlated with the magnitude of density changes. Frequencies of transferrin alleles changed the most when population density was in decline. Changes among the five phenotypic traits were generally uncorrelated with one another, except for skull and mandible shape. Nonmetric traits were selectively neutral when assessed with Q_ST/F_ST analysis, whereas mandible size, mandible shape, and skull shape showed evidence of fairly strong selection. Selection on skull size was weak or nonexistent. We discuss how different assumptions about the genetic components of variance affect Q_ST estimates when phenotypic variances are substituted for genetic ones. We also found that change in mandible size, mandible shape, skull size, and skull shape were greater than expected under a neutral model given reasonable assumptions about heritability and effective population size.     

Une reconstitution surprenante d’un fossile humain : la mandibule magdalénienne du crâne d’enfant Rochereil III

The fragmented pathological skull of a young child was discovered in a Magdalenian level in the Rochereil cave, Dordogne, France, in 1939. The bony fragments were extracted along with the surrounding soil, and completely cleaned in a laboratory. The mandible has been wrongly reconstructed. Among the nine teeth that are present on the mandible, three deciduous molars are human teeth at their correct places. Only one tooth in the incisor–canine block (the right deciduous lateral incisor) is a human tooth, but it is incorrectly positioned on the left side. The other incisors and canines implanted in this child's mandible originated from one or several young adult reindeer. These small animal teeth were probably mistaken for human pathological teeth because the child's skull and mandible showed several pathological lesions. The possibility of faulty reconstitution must be systematically considered when dealing with for all human fossils which have been discovered in the past.     

Skull and mandible formation in the cuckoo (Aves, Cuculidae): contributions to the nomenclature in avian osteology and systematics

The study of the contributions of different bones to the formation of the skeleton in birds is necessary: (1) to establish homologies in comparative anatomy; (2) to delimit each bone structure correctly, mainly in relation to the skull and mandible where the bones are fused to each other in adults; and (3) to standardize nomenclature in avian osteology. In this paper at least one young specimen belonging to each sub-family of Cuculidae was examined in order to identify each bone in terms of boundaries and contributions to skull and mandible formation. These cuckoos specimens were also compared with adults and young of turacos and hoatzin. The results show little variation of skull and jaw among the young cuckoos studied compared with the variations among adult specimens. However, it provides new suggestions for the boundaries and nomenclature of certain osseous structures in the skull and mandible of birds, specifically fissura zona flexoria craniofacialis, prominetia frontoparietalis, crista temporalis transversa, processus squamosalis, fossa laterosphenoidalis, tuberculum laterosphenoidale and processus retroangularis. This study also provides more reliable homologies for use in cladistic analysis and above all it contributes to the phylogenetic position of Cuculidae within Neognathae, specifically the skull formation suggest that turacos and hoatzin are more similar to each other than either is to the cuckoos.     

男性特小颅一例报告

本例特小颅T1的死者为男性,年龄约40岁,身高168cm,中国人。经颅骨各项指标测量和观察,该颅骨的脑颅特小,尤其是额部特别窄小;而面颅则相对较大,上、下颌骨向前突出。颅骨主要的长、宽、高各径和弧、弦、周长等的测量值均比其他报道中的最小值要小;颅容量为602ml,比已报道的最小颅容量1340ml还要小一倍多,故将其称为特小颅。     

人类化石分类中的亚种问题

本文提出怎样认识人属亚种的含义,认为把蓝田猿人陈家窝子和公王岭两地点的化石,分别订为两个亚种是没有根据的和没有意义的。     

The plagiosaurid temnospondyl Plagiosuchus pustuliferus (Amphibia: Temnospondyli) from the Middle Triassic of Germany: anatomy and functional morphology of the skull

The cranial anatomy of the plagiosaurid temnospondyl Plagiosuchus pustuliferus, from the Middle Triassic of Germany, is described in detail on the basis of a newly discovered skull and mandibular material. The highly derived skull is characterized by huge orbitotemporal fenestrae, a reduction of the circumorbital bones – the prefrontal, postfrontal and (probably) postorbital are lost – and the expansion of the jugal to occupy most of the lateral skull margin. Ventrally the extremely long subtemporal vacuities correlate with the elongate adductor fossa of the mandible. The dentition is feebly developed on both skull and mandible. Ossified ?ceratobranchials and ‘branchial denticles’ indicate the presence of open gills clefts in life. The remarkably divergent cranial morphology of P. pustuliferus highlights the extraordinary cranial diversity within the Plagiosauridae, probably unsurpassed within the Temnospondyli. Specific structural aspects of the skull – including an extremely short marginal tooth row, feeble dentition and an elongated chamber for adductor musculature – together with evidence for a hyobranchial skeleton, suggests that P. pustuliferus utilized directed suction feeding for prey capture. © 2009 The Linnean Society of London, Zoological Journal of the Linnean Society, 2009, 155 , 348–373.     

SKULL SHAPE EVOLUTION IN DUROPHAGOUS CARNIVORANS

In this article, we investigate convergent evolution toward durophagy in carnivoran skull shape using geometric morphometrics in a sample of living and extinct species. Principal components analysis indicate that, in spite of the different dietary resources consumed by durophages—that is, bone‐crackers and bamboo‐feeders—both groups of carnivorans share portions of skull phenotypic spaces. We identify by discriminant analyses a shared set of adaptations toward durophagy in the skull of carnivores. However, ancestral states indicate that although durophages reached similar phenotypes, the evolutionary pathways that they followed are different depending upon the family to which they belong. Furthermore, while the carnivoran cranium more closely reflects the nature of the resources consumed—that is, soft or hard and tough items—the mandible shows particular feeding adaptations—that is, bamboo or bone. This finding supports the interpretation that the mandible has more evolutionary plasticity than the cranium, which is more limited to evolve toward a particular feeding adaptation. However, we find that the shapes of the cranium and the mandible are highly integrated for the whole order Carnivora. Published studies of teratological cats and dogs indicate that the role of internal constraints in shaping this pattern of integration is absent or weak and malleable by selection.     

金丝猴颅骨及牙齿的比较形态研究

金丝猴(Rhinopithecus roxellanae M.-E.)自从1870年订名以来,对它的研究多限于分类和个体生态习性的观察描述,至于它的形态解剖方面的论述国内几无报道。国外Hooizer(1950)和Swindler(1976)对其牙齿作了简单扼要的描述,前者并在11例川金丝猴头骨中发现一例左侧上颌骨具有P⁴。这次我们对金丝猴系统的研究过程中,在解剖方面,除了进行各器官系统解剖外,同时还与猕猴、黑叶猴相比较,并对其器官的形态变化和生态生理机能的结合上给以适当注意和解释。     

The Cranial Osteology Of The Middle Triassic Ichthyosaur Contectopalatus From Germany

A new partial skull of the Middle Triassic ichthyosaur Contectopalatus atavus allows many new osteological observations and makes the referral of several additional specimens, including lower jaw material, possible. This aids very much in the understanding of the anatomy of this highly derived mixosaurid species. The lectotype of Ichthyosaurus atavus is shown to be diagnostic and the recent proposal of a neotype is unnecessary. Contectopalatus shows thecodont dentition in all parts of the jaws. The teeth are labyrinthodont at their bases. Some specimens, which are interpreted as very late ontogenetic stages of C. atavus , indicate that Contectopalatus grew very large, reaching four to five times the size of other mixosaurids. Mixosaurid taxonomy is reviewed. Three valid genera can be included in a monophyletic Mixosauridae: Mixosaurus (including M. cornalianus and M. kuhnschnyderi ), Phalarodon Contectopalatus (monotypic). The mixosaurids are the sister group to the remaining ichthyosaurs, apart from the Lower Triassic forms. The status of the Omphalosauridae remains unresolved, but they are not closely related to the mixosaurids, because the durophagous dentition was acquired convergently in the two groups.