新发现的长吻型离龙(双孔亚纲：离龙目)幼年个体——袖珍蒙山龙，兼论新离龙类的个体发育（英文）

离龙是一类生活在中侏罗世至中新世的半水生掠食性动物。白垩纪早期,部分离龙类演化为与现生鳄鱼形态类似的大型长吻爬行动物,称为新离龙类。报道了来自山东省下白垩统蒙阴组的一长吻型离龙新种——袖珍蒙山龙(Mengshanosaurus minimus),正型标本头骨全长仅35 mm,是迄今为止发现的最小新离龙类个体。根据未完全骨化的颅腔和额骨-顶骨间尚存未愈合的圆孔,推测蒙山龙正型标本为一幼年个体。系统发育分析显示,蒙山龙属于新离龙类,具有单个外鼻孔,单一鼻骨和下颞孔开放等新离龙类的共有衍征。在新离龙类内部,蒙山龙分类位置较为基干,为伊克昭龙属(Ikechosaurus)、车尔龙属(Tchoiria)、西莫多龙属(Simoedosaurus)和鳄龙属(Champsosaurus)组成的支系的姐妹群。蒙山龙区别于其他新离龙类的特征包括泪孔位于前额骨与泪骨之间,以及增大的腭面齿(宽度超过上颌齿的1/3)。蒙山龙具有长吻和紧密排列的尖利牙齿,推测离龙类幼体与现生鳄类幼体食性类似,以水生昆虫和无脊椎动物为食。现生鳄类在发育过程中,吻部的形态常发生改变,牙齿也会从尖细的形状转向圆钝;而蒙山龙的吻部和牙齿的形态与已知大体型的成体新离龙类没有明显区别,这说明相较于现生鳄类,新离龙类在发育过程中生态位的变化并不显著。     

云南东部中三叠世始鳍龙类—新属种(英文)

根据一保存完整的骨骼(包括头骨、下颌和全部头后骨骼)建立了鳍龙类的一新属新种——利齿滇东龙(Diandongosaurus acutidentatus gen.et sp.nov.)。标本采自云南省罗平县中三叠世安尼期关岭组上段。新属种既具有肿肋龙类(包括Dactylosaurus,Anarosaurus,Serpianosaurus和Neusticosaurus)吻部两侧不收缩、眶前区域长于眶后区域、眼眶大于上颞孔等典型特征,同时又具有幻龙类(包括Simosaurus和nothosaurians)前颌和下颌前部犬齿型齿发育、上颌具1或2个犬齿型齿等典型特征。新种的额骨和顶骨均愈合,额骨两后外侧支的末端后延超过上颞孔前缘,轭骨和鳞骨相交将眶后骨排除于下颞孔之外,方轭骨发育,锁骨前外侧缘具一突起,3对荐肋以及最前部尾肋的外侧端均未见明显收缩。这些特征也多表现出肿肋龙类和幻龙类的混合特征。此外,新种还具有一些较为独特的特征,包括前额骨和后额骨沿眼眶背缘相交,第3至第8对尾肋的长度超过荐肋,后肢末端发育异常膨大的爪趾骨。系统关系分析表明,滇东龙既不是肿肋龙类也不是幻龙类;它可能与由乌蒙龙、幻龙类和传统的肿肋龙类所构成的分支亲缘关系最近,为始鳍龙类基干类群。     

四川自贡大山铺孙氏鳄属(Sunosuchus)一新种

记述了在四川自贡大山铺发现的孙氏鳄一新种———蜀南孙氏鳄 (Sunosuchusshunanensissp .nov .)。新种窄长的吻部 ,小的颅顶平台 ,额骨沿中线具一纵嵴 ,一对裂隙状的前腭孔位于眶下孔之前方 ,方骨腹面的嵴B特别发育等 ,与孙氏鳄的其他种很相似 ,但新种的吻部特别窄长 ,为吻后部长度的 3倍 ,上颌凹特别发育 ,颅顶平台短而宽 ,颞间部宽度大于眶间部宽度 ,泪骨在眼眶前缘处隆起成嵴 ,下颞孔小 ,呈裂隙状 ,鳞骨侧缘不增厚 ,也无附着上耳盖的沟嵴状构造 ,基枕骨侧缘和外枕骨内腹缘具一明显的隆嵴等 ,与孙氏鳄的其他种有明显区别     

四川自贡晚侏罗世西蜀鳄一新种

记述了四川省自贡市汇东新区自贡市乳品厂发现的西蜀鳄一新种——周氏西蜀鳄(Hsisosuchus chowi sp.nov.)。新种区别于西蜀鳄已知种的特征是:鼻骨后部沿缝合线有一浅的纵凹,额骨的眶缘向上凸起成嵴,沿额骨缝合线也隆起成一微弱的纵嵴,上颞窝的内侧缘向上凸起呈明显的嵴,顶骨具一前中突,侧视颧骨腹缘呈明显的波曲状,眶后骨前侧角约90°,鳞骨后侧突特别拉长,向侧下后方伸展,使鳞骨侧缘明显向内侧弓曲,左右外枕骨的枕髁部分不相接,翼骨的腹中嵴源于翼骨主体部分,内鼻孔位置比较靠前。此外,齿骨外面和夹板骨腹面具有发达的沟和嵴状雕饰,夹板骨参与下颌联合的部分比较长,肩胛片异常扩展,乌喙骨远端宽于近端,肱骨头增厚并强烈向内侧扩展,三角肌嵴发达,桡侧腕骨具发达的尺骨突,尺侧腕骨远端宽于近端,6列荐前部腹部骨板和3列尾部腹部骨板,也可能是周氏西蜀鳄的衍生特征,但这些性状在大山铺西蜀鳄中情况不明,有待更多的材料来证实。杨钟健、周明镇(1953)在建立西蜀鳄属之初就已注意到西蜀鳄是一种特化的鳄类,认为西蜀鳄不仅将原始特征和进步特征混存于一身,而且还具有一些一般鳄类所没有的独特性质。以此为基础,他们建立了西蜀鳄科。目前西蜀鳄类动物发现并不多,仅有1属2种,即重庆西蜀鳄和大山铺西蜀鳄,而且材料不完整,特别是头后骨骼保存不理想。周氏西蜀鳄的发现不仅扩大了西蜀鳄类的分布范围,而且还增加了我们对这一特化鳄类的认识。     

中国陆相上三叠统第一个初龙形类动物(英文)

初步研究了山西省永和县桑壁镇铜川组二段产出的两件初龙形类化石标本 (IVPPV1 2 3 78,V 1 2 3 79) ,在此基础上建立了一新属新种———桑壁永和鳄 (Yonghesuchussangbiensisgen .etsp .nov .)。它以下列共存的衍生特征区别于其他初龙形类 (archosauriforms) :1 )吻部前端尖削 ;2 )眶前窝前部具一凹陷 ;3 )眶前窝与外鼻孔间宽 ;4)眶后骨下降突的后 2 / 3宽且深凹 ;5 )基蝶骨腹面有两个凹陷 ;6 )齿骨后背突相当长 ;7)关节骨的反关节区有明显的背脊 ,有穿孔的翼状的内侧突 ,以及指向前内侧向和背向的十分显著的后内侧突。由于缺乏跗骨的形态信息 ,目前很难通过支序分析建立永和鳄的系统发育关系。但可以通过头骨形态来推测永和鳄在初龙形类中的系统位置。永和鳄有翼骨齿 ,这表明它不属于狭义的初龙类 (archosaurians)。其通过内颈动脉脑支的孔位于基蝶骨的前侧面而不是腹面 ,在这点上永和鳄比原鳄龙科 (Proterochampsidae)更进步 ,这表明与后者相比永和鳄和狭义的初龙类的关系可能更近。在中国早期的初龙形类中 ,达坂吐鲁番鳄 (Turfanosuchusdabanensis)与桑壁永和鳄最接近 ,但前者由于内颈动脉脑支的孔腹位而比后者更为原始。根据以上头骨特征以及枢后椎椎体之间间椎体的存在与否 ,推测派克鳄 (Euparkeri     

记云南罗平三叠纪小型始鳍龙类—新属种

根据一保存基本完整的骨架建立了始鳍龙类的一新属、种——纤细滇美龙(Dianmeisaurus gracilis gen.et sp.nov.)。标本采自云南省罗平县中三叠统关岭组Ⅱ段,为体态细长的小型物种。新属种与同产于该地区的利齿滇东龙(Diandongosaurus acutidentatus Shang et al.,2011)和丁氏滇肿龙(Dianopachysaurus dingi Liu et al.,2011a)身体各部位比例和个体大小接近,头骨均具有吻部两侧不收缩、眼眶显著大于上颞孔的特征。但新种眼眶间距要明显小于上颞孔间距,下颌关节与枕髁位于同一水平位置,锁骨前外侧缘的锁骨前突粗大而厚实,尺骨近端明显宽于远端,有比后两种更多的荐前椎(三属种荐前椎数分别为41、38、39枚)。此外,与滇东龙相对比,新种眶前区短于眶后区,前额骨和后额骨不相交。同时,新种下颌联合短,夹板骨参与下颌联合构成。新种前颌和下颌前部齿虽然也为獠齿(犬齿状齿),但未呈显著增大。头后骨骼对比,虽然新种和滇东龙均具有标志性的锁骨前外侧突,但后者的锁骨前外侧突尖细。与滇肿龙相对比,新种尾前部尾肋细长且未见明显加宽肿胀、仅具一个骨化的远侧腕骨、距骨为圆形且不具有近端凹入。去除数据不全的清镇龙、广西龙和三桥龙后的鳍龙类分支系统学分析表明,滇美龙与滇东龙互为姊妹群,同时它们与贵州龙、马家山龙和滇肿龙一起构成了一仅由在中国发现的属种组成的单系类群。这一单系类群与幻龙类的亲缘关系近于它们与欧洲肿肋龙类(Dactylosaurus,Anarosaurus,Serpianosaurus和Neusticosaurus)的亲缘关系。三种小型始鳍龙类的发现,指示云南罗平地区在三叠纪安尼期中晚期时鳍龙类是一类有较高分异度的海生爬行动物。     

记裂头鳄属(Dibothrosuchus)一新种

本文记述的裂头鳄属-新种 (Dibothrosuchus xingsuensis sp. nov.)的标本采自云南禄丰盆地下禄丰组深红层.通过描述,对裂头鳄属属级特征作了补充.新种的头骨中鳞骨缺失降突;方骨极度向前背方伸展,形成大的耳凹,乌喙骨具后腹突,以及具有鳄类式的腕骨等,表明裂头鳄属应改属为楔形鳄科 (Sphenosuchidae).根据该科各属的头骨中方骨与脑颅侧壁的连接关系,可以清楚地看到楔形鳄科在这局部解剖学上存在一连续的发展过程.在形态上,裂头鳄属和南非的 Sphenosuehus (典型属)最为相近.     

宽头山东鳄(Shantungosuchus brachycephalus Young,1982)的再研究

根据对原标本的进一步修理,本文首先对宽头山东鳄（ShantungosuchusbrachycephalusYoung,1982）进行了重新记述,并对其特征作了修订。其主要特征为：头骨相对较宽;眼前孔小,上下分隔为二;轭骨前端不参与构成但接近眶前孔的后边缘;牙齿尖锐,第三枚上颌齿异常粗壮,比其它上颌齿至少大一倍;腭面诸骨表面光滑;基蝶骨腹面中央凹槽前窄后宽变化显著;侧欧氏管孔位于基蝶骨、基枕骨和外枕骨3者之间;下颌外孔大,齿骨后缘分为上、中、下三支;肩胛骨前外侧肩峰之上,发育一显著的嵴状突起。其次,把它与本属的其他两个种：莒县山东鳄（Shantungosuchuchuhsienensis）和杭锦山东鳄（Shantungosuchushangjinensis）做了比较。就目前的资料,还不能确立山东鳄属各种间的系统关系。     

陕甘宁盆地二马营组的假鳄类

在陕甘宁盆地东北缘二马营组发现的两种假鳄类,经鉴定均属Euparkeridae。其中之一与Euparkeria较相近;根据肩胛骨、肱骨和骨质背板等的显著不同,定名为侨家梁哈拉寨鳄(Halazhaisuchus qiaoensis),新属、新种。依据骨髂形态,另一标本归入世鲁番鳄属(Turfanosuchus),取名沙圪堵吐鲁番鳄(Turfanosuchus shageduensis)、新种。     

华南几种泥盆纪及石炭纪鱼化石

本文所描述的鱼化石有下列一些种属:棘鱼包括二属三种,广西的高氏亚洲棘鱼(新种)及孙氏亚洲棘鱼(新种)系侯鸿飞同志及笔者1957年采自广西桂平新隆村早泥盆世莲花山羣的中部;中华武昌棘鱼系薛志照、陈安泽诸同志及笔者1956—1957年采自武汉蛇     

Primary homologies of the circumorbital bones of snakes

Some snakes have two circumorbital ossifications that in the current literature are usually referred to as the postorbital and supraorbital. We review the arguments that have been proposed to justify this interpretation and provide counter‐arguments that reject those conjectures of primary homology based on the observation of 32 species of lizards and 81 species of snakes (both extant and fossil). We present similarity arguments, both topological and structural, for reinterpretation of the primary homologies of the dorsal and posterior orbital ossifications of snakes. Applying the test of similarity, we conclude that the posterior orbital ossification of snakes is topologically consistent as the homolog of the lacertilian jugal, and that the dorsal orbital ossification present in some snakes (e.g., pythons, Loxocemus, and Calabaria) is the homolog of the lacertilian postfrontal. We therefore propose that the terms postorbital and supraorbital should be abandoned as reference language for the circumorbital bones of snakes, and be replaced with the terms jugal and postfrontal, respectively. The primary homology claim for the snake “postorbital” fails the test of similarity, while the term “supraorbital” is an unnecessary and inaccurate application of the concept of a neomorphic ossification, for an element that passes the test of similarity as a postfrontal. This reinterpretation of the circumorbital bones of snakes is bound to have important repercussions for future phylogenetic analyses and consequently for our understanding of the origin and evolution of snakes. J. Morphol. 274:973–986, 2013. © 2013 Wiley Periodicals, Inc.     

A BASAL MIXOSAURID ICHTHYOSAUR FROM THE MIDDLE TRIASSIC OF CHINA

Abstract:  New specimens of a mixosaurid ichthyosaur are described from the People's Republic of China. They consist of an almost complete skull, forefin and shoulder girdle of a single individual, and a second partial skull from the Anisian Guanling Formation of Guizhou Province that belongs to the same taxon. A phylogenetic analysis shows this species to be the sister-taxon of all other mixosaurids. It is distinguished from Mixosaurus , Contecotpalatus and Phalarodon by features of its dentition and cranial morphology. There is only one maxillary tooth row. The posterior maxillary teeth are blunt and rounded, and much wider than the premaxillary teeth, but they are not strongly elongated anteroposteriorly. The teeth are subthecodontously implanted. The postorbital skull segment is long. The jugal-quadratojugal notch is deep and these two elements remain separated externally. The postorbital separates supratemporal and postfrontal. There are no postaxial ossifications of the forefin. Autapomorphies include a long ventral process of the postorbital lamina of the postorbital as well as characteristic morphologies of the coracoid and humerus. The material is therefore clearly distinguished from other known mixosaurids. It can be referred, on the basis of the features of the humerus and coracoid, to Mixosaurus maotaiensis Young, 1965. As it is generically distinct from Mixosaurus , a new generic name, Barracudasaurus gen. nov. is proposed. The phylogenetic relevance of the external separation of jugal and quadratojugal in some Triassic ichthyosaurs is discussed and it is concluded that it does not demonstrate the initial presence of a lower temporal fenestra in ichthyosaurs. The new material suggests that mixosaurids could have also originated in the Eastern rather than the Western Tethys, as previously assumed.     

似粗弯齿兽的重新鉴定

<正> 产自河南济源王屋山的王屋似粗弯齿兽(Traversodontoides wangwuensis)系杨钟健1974年所记述和命名。当时被归属于犬齿兽类横齿兽科(Traversodontidae)。根据野外记录,化石来自二马营组上部,但在该地点无其他脊椎动物化石发现。最近,在研究和尚沟组掘兽类的同时,对该标本的头骨(古脊椎所登记号V4068)进     

The development of the skull in Acrochordus granulatus (Schneider) (Reptilia: Serpentes), with special consideration of the otico-occipital complex

The skull of Acrochordus has been characterized by the absence of a crista circumfenestralis (a synapomorphy shared by all snakes), and by the absence of a recessus scalae tympani that in other squamates forms by subdivision of the embryonic metotic fissure. These traits have variably been identified as either plesiomorphic or paedomorphic. The study of the development of the osteocranium in a series of cleared and stained embryos of Acrochordus shows a close correspondence to the development of the skull in other snakes. The exception is the formation of the postorbital from two ossification centers. The significance of this observation, which might suggest the embryonic fusion of a postfrontal with a postorbital, remains enigmatic, as it is based on one side only of the skull of a single specimen. By contrast, a rudimentary and modified crista circumfenestralis can be identified in the skull of Acrochordus. Furthermore, absence of a recessus scalae tympani is not due to an undivided fissura metotica, but results from the obliteration of the anterior part of the metotic fissure instead. With respect to this character, Acrochordus is neither plesiomorphic, nor paedomorphic, but autapomorphic. This interpretation of the skull of Acrochordus is compatible with the sister-group relationships this genus shares with colubroid snakes.     

The presence of Compsocerops (Brachyopoidea: Chigutisauridae) (Late Triassic) in southern Brazil with comments on chigutisaurid palaeobiogeography

Abstract: Chigutisauridae is the longest‐lived trematosaurian clade (from early Triassic to early Cretaceous). They were reported in Argentina, Australia, India and South Africa. This contribution reports a putative chigutisaurid specimen in the Carnian of southern Brazil (Santa Maria Formation, Paraná Basin). The material comprises two skull fragments, a mandibular fragment, a clavicular blade and a humerus. Ontogenetic features point to an early development stage of the specimen. The presence of a long, straight and pointed tabular horn, which runs parallel to the skull midline towards its tip, and a distinctive projection in the posterior border of the postparietal indicates a close relationship of the Brazilian chigutisaurid with the Indian Compsocerops cosgriffi. Three distinctive and combined characters suggest that the Brazilian chigutisaurid is a distinctive specimen: the presence of an alar process of the jugal in the ventral margin of the orbit; jugal does not extend well beyond the anterior margin of the orbit; and tabular does not contact the parietal. These characters could justify the erection of a new taxon; however, they might reflect its immature ontogenetic stage as well. Accordingly, we attribute this new specimen to Compsocerops sp. Argentinean and Indian occurrences are dated as Norian, so the presence of a Carnian chigutisaurid in southern Brazil indicates that western Gondwana chigutisaurids have first occupied the Paraná Basin and later migrated towards west (to Argentina) and east (India). However, the presence of ghost chigutisaurid taxa cannot be dismissed, because their long temporal range contrasts with their still short (in comparison with other temnospondyl groups) geographic distribution. Hence, they might have been more geographically widespread than their fossil record suggests.     

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.     

Osteology of Rauisuchus tiradentes from the Late Triassic (Carnian) Santa Maria Formation of Brazil,and its implications for rauisuchid anatomy and phylogeny

As the eponymous type species for rauisuchians, Rauisuchus tiradentes von Huene, 1938 represents an important but inadequately known specimen. The revision of the type material from the Upper Triassic (Carnian) Santa Maria Formation of Brazil reveals new anatomical data and previously unrecognised characters, including three new possible autapomorphies: a knob‐like thickening on the base of the posterior process of the premaxilla; short and ventrally keeled cervicals lacking postzygodiapophyseal laminae; and mid‐caudal vertebrae with an accessory neural spine and a postspinal lamina. Several elements are re‐identified, including a postorbital (originally identified as postfrontal) and a pterygoid (originally identified as a prefrontal), and additional material from a secondary fossil site, originally assigned to R. tiradentes, including a left ilium, is excluded. Based on the recovered information and new morphological data, the systematic position of R. tiradentes is tested in a comparison of two phylogenetic reanalyses. Both analyses differ in respect to the phylogenetic position of R. tiradentes, and recover ‘rauisuchians’ as a paraphyletic assemblage of non‐crocodylomoprh archosaurs. © 2014 The Linnean Society of London