三列齿类的颊齿齿根

本文记述了三列齿类4个属颊齿齿根的构造,比较了它们之间的异同,揭示了齿根的生长过程,证实了三列齿类的颊齿只具一个齿序的推断,并提出了颊齿在生长的同时有向前移动的过程.     

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.     

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.     

辽宁早白垩世义县组一原始鸟脚类恐龙

初步记述了采自辽西地区早白垩世义县组新的原始鸟脚类恐龙化石材料,并依此建立一新属新种上园热河龙（Jeholosaurus shangyuanensis gen. et sp. nov.）。化石产于北票市上园镇陆家屯义县组下部第一段灰白色凝灰质砂岩中,同一层位产出过大量鹦鹉嘴龙化石。上园热河龙的主要鉴定特征包括6个前上颌齿,鼻骨背面发育小孔,前齿骨约为前上颌骨主体长度的1.5倍、未发育股骨前髁间沟、骨不在一平面上,第三趾趾节中第四节最长。上园热河龙具有一些真鸟脚类恐龙的近裔性状,比如眶前孔小,方骨孔大,位于方颧骨侧面,外下颌孔缺失。另外,上园热河龙的股骨近端形态非常接近进步的鸟脚类恐龙。但是上园热河龙发育有6个前上颌齿,上下颌关节处与齿列位于同一水平线,前上颌齿列与上颌齿列位于同一水平线,这些原始特征未见于已知鸟脚类恐龙。上园热河龙确切系统分类位置需要进一步确定。 上园热河龙是义县组中发现的第二种鸟臀类恐龙,增加了这类恐龙在热河生物群中的分异度。     

云南禄丰兽孔类—新属

1972年夏,在云南禄丰盆地采得一批脊椎动物化石。其中有一三列齿科(Tritylo-dontidae)的小头骨,保存相当完好。这类化石早在十九世纪末,在非洲南部、西欧已有发现。当时大多数人把它归入早期哺乳类。1938年,杨钟健等在禄丰发现了卞氏兽(Bienothe-rium),进一步的研究表明,卞氏兽上下颌的连接方式、下颌骨的组成等方面,仍然保留着典型的爬行动物特征。这就使三列齿类正式归于爬行动物。三列齿兽是一类接近于哺乳类的爬行动物,对了解脊椎动物的演化具有重要的科学价值。根据辛博生(Simpson)1928年叙述的三列齿科的特征(颊齿的齿型一致,齿尖新月状,由三个齿列组成,咀嚼方式由下颌骨的前后运动),可看出这一高度特化了的类型,     

17种陆生贝类齿舌的扫描电镜观察及 分类学意义探讨

采用扫描电镜观察了3目10科12属17种陆生贝类的齿舌形态.结果 显示,17种陆生贝类齿舌的中央齿均为1列,侧齿12～218列不等,缘齿0～204列不等.中央齿依齿片上小齿数目分为单齿型、三齿型和多齿型;侧齿与缘齿的形态多样,侧齿齿片上小齿数1～6枚不等,缘齿齿片上小齿数1～10枚不等.结合以往报道的38种陆生贝类齿舌...     

中国最原始的嵌齿象——意外嵌齿象(Gomphotherium inopinatum)在临夏盆地的发现兼论中国的嵌齿象(英文)

临夏盆地下中新统的甘池梁地点发现了一件残破下颌带有m2和m3齿列。在齿列前方,其水平支伸长,并且不向下转折或倾斜。下颌角位置较低。颊齿小,冠面结构特征原始。齿谷在前后方向宽度中等,副齿柱侧及主齿柱中心小尖不分裂,副齿柱中心小尖不发育。这些特征与哈萨克斯坦图尔盖地区早中新世的意外嵌齿象(Gomphotherium inopinatum)相同,应归为该种。这是该种在中国的首次报道,并且是中国发现的最原始的种。进一步讨论了中国的嵌齿象各种的系统关系。维曼嵌齿象(G.wimani)代表了一种在欧亚大陆东部发现的进步类型,可以与欧洲的施泰因海姆嵌齿象(G.steinheimense)相联系。间型嵌齿象(G.connexum)则似乎是属于真正的"狭齿嵌齿象类群",因为其与狭齿嵌齿象(G.angustidens)的颊齿具有相似性。亚似貘型嵌齿象(G.subtapiroideum)或许代表了一个与狭齿嵌齿象不同的分支,而陕西嵌齿象("G.shensiensis")则可能是其中的一种变异。     

新疆吐谷鲁群天山贫齿鳄的再研究

本文对杨钟健1973年记述的—原鳄类成员——天山贫齿鳄 (Edentosuchus tienshanensis) 进行了修订和补充描述,并依据头骨及脊椎的特征将原订的贫齿鳄科 Edentosuchidae 归人中鳄亚目.文中对这一鳄类的年龄及齿列的功能形态进行了初步的探讨.     

安徽潜山古新世裂齿目一新属兼论中国古新世裂齿类

记述了安徽潜山盆地古新世裂齿目一新属种 ,命名为潜水本爱兽 (Benaiusqianshuiensisgen .etsp .nov .)。标本产于望虎墩组下段底部 ,为一带犬齿和完整颊齿列的左下颌骨。新种的主要特点是 :个体较小 ,下齿列齿式 2 + ?·1·4·3,i2略有增大 ,p1存在但退化成单根且侧扁 ,p3无下后尖 ,p4次臼齿化且无下内尖 ,下三角座前后压缩且下前尖退化 ,m3三叶。中国曾经记述的和被认为是裂齿类的古新世哺乳动物共有 9个属种 :Lofochaiusbrachyo dus、Meiostylodonzaoshiensis、Anchilestesimpolitus、Dysnoetodonminuta、Interogaledatangensis、Pletho rodonchienshanensis、Huananiusyoungi、Yuesthonyxtingae和Simplodonqianshanensis。经过仔细比较研究它们的齿列 ,作者认为 ,Lofochaius、Meiostylodon、Interogale、Plethorodon和Simplodon可能属于裂齿类 ,而Anchilestes、Dysnoetodon、Huananius和Yuesthonyx则可能与裂齿类没有很近的亲缘关系。广东南雄盆地上湖组Lofochaiusbrachyodus的P1和P2退化、P4有一定程度的臼齿化、外架窄、主尖锥状、前尖棱和后尖棱的颊侧端内收 ,显示了裂齿类的特点。湖南茶陵盆地枣市组Meiostylodonzaoshiensis的i2增大、上臼齿主尖锥状、柱尖和后附尖发育、前尖棱和后尖棱的颊侧?     

河南始新世中兽科化石

这篇短文中记述了肉齿类(Creodontia)中兽科(Mesonychidae)的三个新种。中兽科是全北区早第三纪(中古新世到早渐新世)的原始食肉类,齿列很特殊,沒有裂齿,据推想主要是杂食性动物。已知的化石共代表11个属,过去在北美发现的材料较多,在欧洲和亚洲则不甚重要,只在我国内蒙二连地区的伊尔丁曼纳层(上始新统)中有少量发现。近几年来,在亚洲有许多新的发现,包括蒙古人民共和国的下始新统(或上古新统)     

On the phylogenetic position of monotremes (Mammalia,Monotremata)

Henosferida from the Middle-Upper Jurassic of Western Gondwana is the most probable sister group for monotremes. They share the derived pretribosphenic structure of lower molars combined with the presumably absent protocone on the upper molars and the plesiomorphic retention of postdentary bones and pseudangular process of the lower jaw. In addition, the two groups share the dental formula with three molars and the position of the Meckel’s groove, which passes ventral to the mandibular foramen. In the course of subsequent evolution, monotremes acquired the mammalian middle ear with three auditory ossicles independently of therian mammals and multituberculates. Jurassic Laurasian Shuotheriidae are probably a sister group of the Gondwanian clade Henosferida + Monotremata. The Jurassic shuotheriid Pseudotribos shows a great plesiomorphic similarity to monotremes in the structure of the pectoral girdle, with a large interclavicle immovably connected to the clavicle. In the lineages leading to therian mammals and multituberculates, the pectoral girdle changed probably independently and in parallel in connection with the establishment of the parasagittal posture of the forelimbs (reduction of the interclavicle, mobile articulation of the interclavicle with clavicle, reduction of the procoracoid, and development of a supraspinous fossa of the scapula) and formation of the mammalian middle ear with three auditory ossicles.     

Altered alignment of the shoulder girdle and cervical spine in patients with insidious onset neck pain and whiplash-associated disorder

Clinical theory suggests that altered alignment of the shoulder girdle has the potential to create or sustain symptomatic mechanical dysfunction in the cervical and thoracic spine. The alignment of the shoulder girdle is described by two clavicle rotations, i.e, elevation and retraction, and by three scapular rotations, i.e., upward rotation, internal rotation, and anterior tilt. Elevation and retraction have until now been assessed only in patients with neck pain. The aim of the study was to determine whether there is a pattern of altered alignment of the shoulder girdle and the cervical and thoracic spine in patients with neck pain. A three-dimensional device measured clavicle and scapular orientation, and cervical and thoracic alignment in patients with insidious onset neck pain (IONP) and whiplash-associated disorder (WAD). An asymptomatic control group was selected for baseline measurements. The symptomatic groups revealed a significantly reduced clavicle retraction and scapular upward rotation as well as decreased cranial angle. A difference was found between the symptomatic groups on the left side, whereas the WAD group revealed an increased scapular anterior tilt and the IONP group a decreased clavicle elevation. These changes may be an important mechanism for maintenance and recurrence or exacerbation of symptoms in patients with neck pain.     

Ontogenesis of the scapula in marsupial mammals, with special emphasis on perinatal stages of didelphids and remarks on the origin of the therian scapula

The development of the scapula was studied in embryonic and postnatal specimens of Monodelphis domestica and perinatal specimens of Philander opossum, Caluromys philander, and Sminthopsis virginiae using histological sections and 3D reconstructions. Additionally, macerated skeletons of postnatal M. domestica were examined. This study focused on the detachment of the scapulocoracoid from the sternum and on the acquisition of a supraspinous fossa, a supraspinatus muscle, and a scapular spine, all these events associated with the origin of the therian shoulder girdle. In none of the specimens is there a continuity of the cartilaginous scapulocoracoid with the sternum, even though the structures are in close proximity, especially in S. virginiae. At birth, the first rib laterally presents a pronounced boss that probably contacts the humerus during certain movements. Only the acromial portion of the scapular spine, which originates from the anterior margin of the scapular blade, is preformed in cartilage. The other portion is formed by appositional bone ("Zuwachsknochen"), which expands from the perichondral ossification of the scapula into an intermuscular aponeurosis between the supra- and infraspinous muscles. This intermuscular aponeurosis inserts more or less in the middle of the lateral surface of the developing scapula. Thus, the floor of the supraspinous fossa is present from the beginning of scapular development, simultaneously with the infraspinous fossa. The homology of the therian spine with the anterior border of the sauropsid and monotreme scapula is questioned. We consider the dorsal portion (as opposed to the ventral or acromial portion) of the scapular spine a neomorphic structure of therian mammals.     

Postcranial anatomy of Haldanodon exspectatus (Mammalia, Docodonta) from the Late Jurassic (Kimmeridgian) of Portugal and its bearing for mammalian evolution

The postcranium of the Late Jurassic docodont Haldanodon exspectatus Kühne & Krusat, 1972 is represented by a partial skeleton and isolated bones of other individuals from the Late Jurassic (Kimmeridgian) of the Guimarota coal mine in Portugal. Haldanodon exhibits adaptations for a fossorial lifestyle such as stout and short limb bones and humeri with greatly expanded distal joints and strong deltopectoral crests. Short first and second phalanges and moderately curved and laterally compressed terminal phalanges with lateral grooves suggest that Haldanodon was a scratch-digger. The dorso-ventrally elongated, triangular scapula has a convex transverse profile with strongly laterally reflected anterior and posterior scapula margins, enclosing a deep trough-like 'infraspinous fossa'. A supraspinous fossa is not developed. The saddle-shaped glenoid facet is mainly formed by the coracoid and orientated antero-ventrally indicating a sprawling gait. No epiphyses were detected and the wide size range of humerus and femur possibly indicate a lifelong growth. Haldanodon is more derived than Morganucodon by complete reduction of the procoracoid, absence of the procoracoid foramen, and a peg-like coracoid. It shares with monotremes a postscapular fossa that is absent in Morganucodon . A PAUP analysis based on 280 cranio-dental and postcranial characters corroborated the position of Haldanodon above morganucodontids and below Hadrocodium .  © 2005 The Linnean Society of London, Zoological Journal of the Linnean Society , 2005, 145 , 219–248.     

Age estimation of adolescent and young adult male and female skeletons II, epiphyseal union at the upper limb and scapular girdle in a modern Portuguese skeletal sample

This study completes previously reported ages for timing of epiphyseal union in the postcranial skeleton in a recent sample, with data from the scapula, clavicle, humerus, radius, and ulna. A sample of 121 individuals between the ages of 9 and 29 (females = 65, males = 56) was derived from the Lisbon documented skeletal collection. Epiphyseal union was scored at 16 anatomical locations, using a three-stage scheme: 1) no union; 2) partial union; and 3) completed union, all traces of fusion having disappeared. In the upper limb, the epiphyses of the elbow are the first to fuse at around 11 to 15 years of age, followed by those of the shoulder and wrist. In the scapular girdle, the coracoid area is the first to fuse, followed by the glenoid surface and remaining epiphyses, with the medial clavicle fusing last, by the age of 25-27. There is a sex difference in maturation, with females showing an advance relative to males of about 2 years in the upper limb. Sex differences in maturation are less noticeable in the scapular girdle, but data suggest that females are also ahead of males. Results suggest overall similar age ranges for stages of union as previous dry bone observations, but some studies show significant divergences which seem to derive from methodological issues. Although some radiographic reference standards provide comparable age ranges, they should probably be avoided when aging skeletal remains.     

Treatment of Combined Injuries of the Axillary and Suprascapular Nerves with Scapulothoracic Dissociation

A 20-year-old man suffered the combined axillary and suprascapular nerve palsies associated with scapulothoracic dissociation by motorcycle accident. The dislocated shoulder girdle was reduced and stabilized with osteosynthesis of the fractured clavicle and reattachment of the trapezius avulsed from the scapular spine for removal of continuous traction force to these damaged nerves. Because of no evidence of recovery on manual muscle test and electromyogram, exploration for these nerves was administered 6 weeks after injury. Although neurolysis of both nerves revealed neural continuity, excessive tension still existed on the suprascapular nerve. It was thought that previous operation in which the shoulder girdle had been reduced and stabilized as much as possible could not achieve complete anatomical reduction of the scapula. As an additional treatment, medial walls of the suprascapular and spinoglenoid notches were shaven to relax the suprascapular nerve. After a year, complete recovery of both the axillary and suprascapular nerve was identified. Although scapulothoracic dissociation is commonly recognized as massive injury of the shoulder girdle with poor prognosis because of existence of accompanied severe neurovascular injuries, there are more than a few cases in which partial damage on the infraclavicular brachial plexus is only accompanied. In case of them, there is the possibility of lesions in continuity of the nerves in which good prognosis might be expected with surgical intervention including early reduction of the shoulder girdle for removal of excessive tension to the damaged nerve.     

Observations on the monotreme interclavicle

Attention is drawn to the presence of a constant, though commonly ignored, element (the "pro-osteon" of Parker, 1868) in the constitution of the monotreme interclavicle (episternum) The probable nature and the fate of this element, peculiar to the immature interclavicle only, are described and its morphological significance is demonstrated to be epiphyseal. The epiphyses of the monotreme shoulder girdle are reviewed as to number, arrangement and fate. The occurrence is reported in a Tachyglossus skeleton of supernumerary (para-pre-coracoid) ossicles of which a possible interpretation is given.     

云南兽(三列齿类爬行动物)的耳区结构

本文介绍了以短吻云南兽为代表的一种耳区结构.它表明在三列齿类爬行动物里已经出现有发育的耳蜗壳以及在其内侧通过的颈内动脉等进步性质,听腔亦趋封闭.云南兽的中耳腔外侧出现了一条曲折的骨质外耳道,侧枕骨突外侧明显的沟可能表明方骨后耳膜之存在.     

Development of the head and pectoral skeleton of Polypterus with a note on scales (Pisces: Actinopterygii)

Comparative study of the bony head and pectoral girdle skeletons of fishes requires the establishment of sound and acceptable homologies. In this paper, the bony elements seen in a number of species of Polypterus (and Erpeloichlhys ) are described in terms of several developmental stages and the mature condition. Variations in these bones are considered in a developmental sense. As a part of the problem of bone development, a summary account of lateral-line development is included.
A number of particular problems of homology are discussed in some detail. The most radical differences of view involve the endocranial bones. The ideas of Patterson (1975) are examined and an alternative interpretation offered. The main bone in the posterolateral angle of the endo-cranium is viewed as the pterotic-epiotic. The epiotic of the teleost is seen not as the homologue of the epioccipital of the pholidophorid but a part of the so-called "pterotic" of those fishes. Other endocranial problems appear to be of a similar (interpretative) nature. The suspensorium of Polypterus is peculiar in lacking a symplectic and an interhyal. The branchial skeleton is quite like that of a "palaeoniscoid". The pectoral girdle presents a number of problems such as the form of the posttemporal, the lack of a sensory canal on the supracleithrum and the lack of an interclavicle.
The subject matter of this paper, and other papers by this author on the development of bones in fishes, lead to several developmental concepts. These are summarized in 18 statements. A table (Table II) summarizes some of the anatomical information useful in taxonomy in terms of being derived, primitive or unique.     

MSCT-3D技术在动物与人骨骼形态比较研究中的应用

目的应用MSCT-3D显示技术比较正常贵州香猪、Marshall比格犬、恒河猴与人上肢带骨及躯干骨的形态学差异。方法采用MSCT分别对贵州香猪、比格犬和恒河猴进行CT全身扫描并进行图像重建,观察其上肢带骨、躯干骨形态结构与人的异同。结果比格犬、恒河猴、贵州香猪脊椎骨和肋的基本组成与人相同,脊椎骨由椎体和附件组成,肋骨包括真肋、假肋和浮肋。而脊柱曲度、各段椎骨数目、胸骨结构、肋的数目、胸肋连接、上肢带骨的组成与人不同,恒河猴的脊柱曲度和上肢带骨连接与人相同,有颈、胸、腰、骶四个生理性弯曲并由锁骨和肩胛骨共同连接自由上肢骨,比格犬和贵州香猪只有颈、胸腰、骶三个生理性弯曲,仅由肩胛骨连接自由上肢骨。结论恒河猴躯干骨和上肢带骨与人有良好的相似性,而比格犬和贵州香猪与人差别较大。MSCT-3D技术为实验动物形态学比较研究提供了一种相对无创、快速、可以在体研究并动态连续观察的科学有效方法。