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1.
描述Plagiolaria nandanensis Chang的头、胸肋和尾的腹边缘,指出它的颊角腹边缘与Phacops guang-xiensis Chang近似,头前腹边缘宽,并靠后。胸肋腹边缘保存较好,肋腹边缘上的潘杰尔脊形态变化不大,但前后则有微小差异。尾腹边缘分两部分,在近外侧有一较明显的凹槽,这是当三叶虫卷曲时与头腹边缘结合的相适应的构造。没有发现卷曲标本,在南丹,90%以上几乎全是蜕壳标本,头与胸尾部分离。但是从腹边缘构造看,比Plagiolaria具更完善的卷曲能力,像其他的phacopids一样,头与尾的结合相当完善,胸肋末端在卷曲时插入头颊角腹边缘的锯齿形沟中,各肋端以其腹边缘上的潘杰尔脊挡住后一肋端的前缘。  相似文献   

2.
桨肋虫的卷曲   总被引:1,自引:0,他引:1  
桨肋虫(Remopleurides Portlock,1843)是奥陶纪常见的三叶虫。(1974)统计过桨肋虫的种,大部分产于中、上奥陶统。绝大部分的描述,都是根据分散的头部、胸部和尾部。 Whittington(1950)曾详细地描述了桨肋虫的各种构造。(1961)描述了 Remopleurides pisiformis的卷曲标本,但胸后部及尾节保存不好。(1975)描述了一些保存零散的标本。一些国家的学者研究了不少酸解泡出的标本(如Webby,1973;Bergstrom,1973;Chatterton and Ludvigsen,1976),虽然保存完整的很少,但对头部腹边缘、颊角腹边缘、肋腹边缘和尾腹边缘的构造,基本上已经清楚。Bergstrom(1973)在论三叶虫形态、生活及分类时,专门讨论了桨肋虫的卷曲,但所用标本卷曲不完善。Beoep(1948)描述了哈萨克斯坦  相似文献   

3.
广西镜眼虫的潘杰尔器官   总被引:1,自引:1,他引:0  
韩乃仁 《古生物学报》1993,32(4):490-494
研究Phacops kuangxiensis Chang的颊角腹边缘外模标本,对其头部腹边缘观察并描述.头前部的结合沟是尾腹边缘末端伸入的地方,为半圆形.颊角腹边缘近锯齿状沟为第2胸肋到第11胸肋末端当卷曲时在头腹边缘上的结合沟.近颊角横向的平切的坑痕为第一胸肋前缘滑入头腹边缘的结合沟.  相似文献   

4.
郭英兰  蒋毅 《菌物系统》2000,19(4):445-448
报道10种尾孢菌,其中有2个新种:蒿尾孢Cercospora artemisiae和筒轴茅生尾孢Cercospora rottboelligina,中国新记录种有鸭跖草生尾孢Cercospora commelinicola,秋英尾孢Cercospora cosmi,凤毛菊尾孢Cercospora ratibidae和苦苣菜尾孢Cercospora sonchi。文中为新种提供了拉丁文描述并附图,研  相似文献   

5.
陈樟福  张贞华 《蛛形学报》1995,4(2):140-141
对蟹蛛科Thomisidae的尾莫蟹蛛Monaesescaudatus雄蛛作了描述。  相似文献   

6.
本文报道9种尾孢菌,其中有2个新种:蟹甲草尾孢 Cercospora cacaliae Y. L. Guo & Y.Jiang和菜蓟尾孢Cercospora  cynarae Y. L. Guo & Y. Jiang,中国新记录种有迪氏尾孢Cercosporademetrioniana  G. Winter,田菁生尾孢 Cercospora  glothidiicola  Tracy &  Earle,甘草尾孢 Cercosporaglycyrrhizae  (Savulescu & Sandu)Chupp,野桐尾孢Cercospora malloti Ellis &  Evsrh,木薯尾孢Cercospora manihobae Viegas,补骨脂尾孢 Cercospora psoraleae-bituminosae Savul.& Sandu和香豆尾孢Cercospora traversiana Sacc。文中为新种提供了拉丁文描述并附图,研究的标本保存在中国科学院微生物研究所菌物标本馆(HMAS)。  相似文献   

7.
该文报道从有庄动物园一只死亡的斑海豹Phlcoa vitulina中采集的一种线虫,旋尾双瓣线虫Dipetlaonema spirocattda(Leidy,1858)Anderson,1959。这个虫种与Anderson的描述基本相同,但虫体的大小、雄虫尾乳突的数目以及左交合刺的长度与Anderson的描述略有不同。该种线虫在我国首次报道,为我国新纪录种。  相似文献   

8.
报道犹惊螨属EvimirusKarg,1963在中国的发现,并描述尾足犹惊螨Evimirusuropolidinus(Berlese,1903)的雄螨。  相似文献   

9.
本文描述采自内蒙古自治区凉需谷子Setaria italica根部的线虫一新种,即细尾盘旋线虫Rotylenchus tenericaudatus sp.nov.。新种主要的鉴定特征是食道腺覆盖肠很短,尾细长,明显弯曲,有一个腹突。  相似文献   

10.
利用必良的Cou and Fasman方法和Prosis软件包中的Robson方法,对四个T-复合物多肽1(TCP1)及五个同源蛋白南进行结构预测。预测结果显示,TCP1中可能存在两个结构域及结构域中间的一个“铰链区”。推测这两个结构域可能是α/β筒状结构,一段公认的ATP结合区、中心为87-91位的GDGTT,在二级结构预测中显示无规卷曲。  相似文献   

11.
Although it is common knowledge that many trilobites enrolled, behavioral and functional aspects of enrollment are not at all well understood. Taphonomic details portrayed by enrolled trilobites in the Middle Devonian Hamilton Group (New York State) indicate that enrollment was a complex and morphologically constrained behavior. The trilobites Phacops rana (Green) and Greenops boothi (Green) are frequently enrolled in Hamilton strata; biostratinomic data indicate two very different enrollment postures. Interlocking morphologies (coaptative devices) and apodeme structure and disposition indicate that these postures reflect specific behaviors which involved interaction between tergal structures, inferred musculature, and the substratum. Phacops enrolled by burrowing forward and down into the sediment; dorsal muscles, attached to prominent articulating half-rings, imbricated the thorax such that each lappet overlapped the next posterior segment and locked into a posterior pleural facet. The pygidium was brought into place as the posterior segments of the thorax were placed into vincular notches along the lateral margin of the ventral cephalon. The pygidium locked with the cephalic vincular furrow to complete ‘perfect sphaeroidal’ closure. Greenops enrolled with the cephalon in an upright position at the sediment surface; a submarginal furrow on the ventral surface of the pygidium received the anterior rim of the cephalon. Relatively narrow articulating half-rings limited pleural rotation. Segments were loosely locked into narrow facets at the anterior margin of the next posterior lappet. In spite of rudimentary lappet and half-ring structures, Greenops displays an elaborate system of thoracopygidial muscles which involved dorsoventral and longitudinal attachments along the thorax and into the pygidium. Phacops, in contrast, displays very poorly developed apodemes which occur in the thorax only. Longitudinal muscle strength was likely less important during Phacops enrollment than is evident for the Greenops enrollment procedure. Conversely, Phacops clearly relied to a great degree upon competent closure devices which are poorly developed in Greenops. Biostratinomic data reveal different enrollment behaviors which reflect the function of different enrollment-related morphologies present in each species.  相似文献   

12.
13.
In this paper, we define temporal and spatial subdivisions of the embryonic head mesoderm and describe the fate of the main lineages derived from this tissue. During gastrulation, only a fraction of the head mesoderm (primary head mesoderm; PHM) invaginates as the anterior part of the ventral furrow. The PHM can be subdivided into four linearly arranged domains, based on the expression of different combinations of genetic markers (tinman, heartless, snail, serpent, mef-2, zfh-1). The anterior domain (PHMA) produces a variety of cell types, among them the neuroendocrine gland (corpus cardiacum). PHMB, forming much of the “T-bar” of the ventral furrow, migrates anteriorly and dorsally and gives rise to the dorsal pharyngeal musculature. PHMC is located behind the T-bar and forms part of the anterior endoderm, besides contributing to hemocytes. The most posterior domain, PHMD, belongs to the anterior gnathal segments and gives rise to a few somatic muscles, but also to hemocytes. The procephalic region flanking the ventral furrow also contributes to head mesoderm (secondary head mesoderm, SHM) that segregates from the surface after the ventral furrow has invaginated, indicating that gastrulation in the procephalon is much more protracted than in the trunk. We distinguish between an early SHM (eSHM) that is located on either side of the anterior endoderm and is the major source of hemocytes, including crystal cells. The eSHM is followed by the late SHM (lSHM), which consists of an anterior and posterior component (lSHMa, lSHMp). The lSHMa, flanking the stomodeum anteriorly and laterally, produces the visceral musculature of the esophagus, as well as a population of tinman-positive cells that we interpret as a rudimentary cephalic aorta (“cephalic vascular rudiment”). The lSHM contributes hemocytes, as well as the nephrocytes forming the subesophageal body, also called garland cells.  相似文献   

14.
云南文山大窗鱼(Macrothyraspis)属一新种   总被引:1,自引:1,他引:0  
记述了产于云南文山古木早泥盆世坡松冲组华南鱼类大窗鱼一新种——长矛大窗鱼(Macrothyraspis longilanceus sp.nov.)。新种头甲呈头盔形,吻突与角均很发育,中背孔呈后缘前凹的桃形,头甲背面具一对蚕豆形的背窗,纹饰为细小的粒状瘤点,这些特征与属型种——长角大窗鱼(Macrothyraspis longicornis)相似。但新种吻突特别长,约为头甲中长的2 倍,眶孔背位,两个背窗之间脑腔和迷走腔区域相对较宽,两个侧向延伸的角向后倾斜,末端不前翘等,与属型种区别明显,应为该属的一新种。  相似文献   

15.
皖北志留纪盔甲鱼类的新发现   总被引:6,自引:3,他引:3  
本文记述了盔甲鱼类的一新属种——珍奇秀甲鱼(Geraspis rara gen. et sp. nov.),它代表—新科(Geraspididae fam. nov)。头甲及其后覆盖鳞片部分呈正常连接。主要特征为:间带短,角呈狭长的三角形,伸向后方。侧背沟靠近头甲中背线。鳞为小而密集的菱形。  相似文献   

16.
Amphids, and the cephalic and labial papillae of Meloidogyne incognita males were examined in detail by electron microscopy. Each amphid basically consists of an amphidial gland, a nerve bundle and an amphidial duct. The gland is a broad microvillous organ with a narrow anterior process, which is closely associated with the amphidial duct. A posterior process of the gland contains secretory organelles and proceeds along the esophagus with the lateral cephalic nerve bundle. The nerve bundle penetrates the broad portion of the gland and, subsequently, individual nerve processes (dendrites) separate from one another, thus forming the sensilla pouch which is enveloped by the gland. Anterior to the pouch, the dendrites converge as they enter and eventually terminate in the amphidial duct. The external opening of the duct is a broad slit which separates the cheek, the outermost part of the lateral lip, from the remainder of the lip region. M. incognita males have six inner labial papillae and four outer cephalic papillae which are each innervated by two and one cilia, respectively. In labial papillae, the cilia appear to terminate at the base of a pore opening, whereas in cephalic papillae each cilium terminates beneath the labial cuticle.  相似文献   

17.
黑龙江密山—宝清早泥盆世盾皮鱼类化石   总被引:1,自引:0,他引:1  
<正>1993年,原地矿部沈阳地质矿产研究所苏养正先生将其在黑龙江省东北部密山及宝清下黑台组中采到的5件泥盆纪鱼化石送交王士涛鉴定。经过修理和观察后认为,这些骨片属于盾皮鱼类(Placoderms)。这是迄今为止在东北地槽区内首次发现的泥盆纪鱼类化石,具有重要的生物地层学及古动物地理学意义。  相似文献   

18.
A new species of philometrid nematode (Nematoda: Philometridae), Philometroides buirnurensis sp. n., is described and illustrated on the basis of female specimens from subcutaneous tissues of the inner surface of the abdominal cavity and the bile duct of cyprinid fishes Leucisuus waleckii (Dybowski), 1869 (type host), Pseudaspius leptocephalus (Pallas), 1776 and Hemiibarbus labeo (Pallas), 1776, from the Buir Nur Lake, a boundary lake between China and Mongolia, on southwest of the Hulun Buir League in the Inner Mongolia Autonomous Region of China. The new species distinctly differs from its congeners mainly in that the posterior half of its body is tapered and conspicuously narrower than the anterior region and that both the head and tail ends are rounded. The cuticular bosses are distributed extensively at both ends but poorly on the middle part of the body. The most peculiar feature of the bosses situated at both ends was their lobe- or rodlike shape and their transverse orientation. Four pairs of submedian outer cephalic papillae and 1 pair of caudal papilla are all relatively large. The new species differs from the most similar congener, Philometroides ganzhouensis Yu, 1998, in having 4 inner cephalic papillae and in the presence of 2 caudal papillae in mature specimens.  相似文献   

19.
滇东南早泥盆世无颌类   总被引:4,自引:3,他引:1  
文中记述了华南鱼类两个新属,即 Gantarostrataspis gengi gen. et sp. nov. 和 Gumuaspis rostrata gen. et sp. nov.,同时对含鱼层的时代进行了讨论.  相似文献   

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