鄂西早志留世三叶虫Aulacopleura(Aulacopleura)wulongensis Wang(1989)的个体发育及Aulacopleurinae亚科的系统演化  

ONTOGENY OF THE SILURIAN TRILOBITE AULACOPLEURA (AULACOPLEURA) WULONGENSIS WANG OF WESTERN HUBEI AND ITS IMPLICATIONS FOR THE PHYLOGENY OF THE AULACOPLEURINAE

作　　者：袁文伟[1] 李罗照[2] 周志毅[1] 张存善 

机构地区：[1]中国科学院南京地质古生物研究所,南京210008 [2]江汉石油学院地质系,湖北荆州434102

出　　处：《古生物学报》2001年第3期388-398,共11页Acta Palaeontologica Sinica

基　　金：国家基金委特殊学科人才培养基金 ;国家重点基础研究专项经费 (G2 0 0 0 07770 0 ) ;中国科学院南京地质古生物研究所现代古生物学和地层学开放研究实验室基金 ( 0 0 3119) ;国务院三峡工程建设委员会办公室经费;中国长江三峡工程开发总公司专项经费 ;中国科学

摘　　要：记述了采自鄂西地区早志留世Llandovery (Aeronian)的三叶虫Aulacopleura (Aulacopleura)wulongen sisWang的个体发育。运用分支分析研究了深沟肋虫亚科 (Aulacopleurinae)各种的最佳聚类 ,确定该亚科目前仅含Aulacopleura一属 ,Songkanina属是Aulacopleura (Paraulacopleura)亚属的同物异名。Aulacopleura一属的祖先种为A .szechuanica ,在系统演化中存在幼型形成和过型形成两种异时发育现象 ,Aulacopleura (Paraulacopleura)各种为该祖先种的幼型形成后裔 ,而Aulacopleura (Aulacopleura)各种为它的过型形成后裔。Ontogenetic material of Aulacopleura (Aulacopleura) wulongensis was collected from the Llandovery (Aeronian) shales at Jianyangping, Xinshan County, Hubei Province, China. This work attempts to describe the ontogenetic series of the species and to discuss the phylogeny and taxonomy of Aulacopleurinae. A cladistic analysis using 20 species of 2 genera (Aulacopleura and Songkania) lends supports to a monophyletic Aulacopleuriae. Diagnosis and ontogeny of Aulacopleura (Aulacopleura) wulongenis Wang (1989) Diagnosis Aulacopleura (Aulacopleura) with glabella of 60%—65% the cranidial length. Thorax of l6 segments with axis occupied 26.5% the thoracic width anteriorly. Pygidium 25% as long as wide, axis with 3 rings and a terminal piece. Ontogeny The protaspis of A. (Aulacopleura) wulongensis is identical with that of Songkania smithi as recorded by Adrain and Chatterton (1995). Anaprotaspis: Type B protaspis (see Chatterton et al., 1999); inverted saucer-shaped; 0.26 mm in width and 0.27 mm in length; posterior margin between the marginal spines strongly reentrant, axis extending to posterior margin but not to anterior margin. Metaprotaspis: Type C protaspis, according to Chatterton et al. (1999), includes Metaprotaspis 1 and 2. Metaprotaspis 1 circular in outline, 0.39—0.4 mm in width, 0.4—0.4l mm in length; axis moderately convex. Metaprotaspis 2 0.43 mm in width and 0.53 mm in length; protocranidium separated from the protopygidium by a distinct transverse furrow, with 3 pairs of glabellar furrows. Ontogenetic trends during the meraspid period of A. (A.) wulongensis include: the shortening of glabella, and the consequent widening (sag.) of preglabellar area; the progressively abaxially shifting of both anterior and posterior branchs of facial suture; the increasing in the relative size of L1, the narrowing of the thoracic axis, and the corresponding widening of the pleural areas; the increasing in the number of thoracic segments; the decreasing in the relative pygidial l

关 键 词：三叶虫 早志留世 鄂西地区 个体发育 系统演化 异时发育 

分 类 号：Q915.819[天文地球—古生物学与地层学]