在西准噶尔晚泥盆世陆相地层中发现首例缺棘短胸节甲鱼类  

The first aspinothoracid arthrodire from the Late Devonian continental strata are found in western Junggar, Xinjiang

作　　者：刘一龙 纵瑞文[2] 龚一鸣[1,2] Yilong Liu;Ruiwen Zong;Yiming Gong(School of Earth Sciences,China University of Geosciences,Wuhan 430074,China;State Key Laboratory of Biogeology and Environmental Geology,China University of Geosciences,Wuhan 430074,China)

机构地区：[1]中国地质大学(武汉)地球科学学院,武汉430074 [2]中国地质大学,生物地质与环境地质国家重点实验室,武汉430074

出　　处：《科学通报》2020年第21期2256-2265,共10页Chinese Science Bulletin

基　　金：国家自然科学基金(41872034,41702006,41290260)资助。

摘　　要：记述了新疆西准噶尔晚泥盆世早法门期月骨鱼科(属于盾皮鱼纲节甲鱼目短胸节甲鱼亚目缺棘短胸节甲鱼超科)一新属——布龙鱼(Bulongosteus gen.nov.).新属发现于朱鲁木特组上部辫状河相砾岩和含砾砂岩中,新属的主要特征是:中颈片呈前缘前凸、后缘前凹的三角形,两侧微内凹;副颈片后缘超过中颈片后缘,发育两条感觉管;眶前片加大以致形成眼眶的前背缘,表面具有较为密集的瘤点;缘片前缘加厚形成眼眶后缘,3条感觉管呈明显"Y"字形;后腹侧片细长.布龙鱼是在新疆首次发现的节甲鱼类,也是缺棘短胸节甲鱼类在陆相沉积中的首次发现,丰富了我国缺棘短胸节甲鱼类的化石记录,扩展了缺棘短胸节甲鱼类的地理分布和生态范围,也表明缺棘短胸节甲鱼类同晚泥盆世众多鱼类一样也是一类广盐性鱼类.Arthrodira is the most widely distributed and diversified subgroup of Placodermi,which itself is the most diverse major group of the Devonian jawed vertebrates.Arthrodires were traditionally divided into the basal,paraphyletic"Dolichothoraci"and the highly nested monopPyletic Brachythoraci,the latter of which displays reduction of body armor.Among brachythoracids,the Coccosteomorphi and Pachyosteomorphi further form a nested monophyletic Eubrachythoracidi.The sister group relationship between Coccosteomorphs and Pachyosteomorphs has been supported by most phylogenetic analyses,but the basal members and their interrelationships in these two groups are still unstable.Coccosteomorphs and pachyosteomorphs are the most diverse arthrodires in the Middle and Late Devonian.Among them,coccosteomorphs are found in strata of the lacustrine and littoral-neritic facies,while the pachyosteomorphs are mostly marine.Selenosteidae,one of the most well-known families in Pachyosteomorphi,are found in marine strata of Europe,North America,and North Africa.Junqing Wang found the nuchal plate of suspected Selenosteidae in the Xiejingsi Formation(early Famennian,Late Devonian)in Hunan Province,China,but due to the lack of identification features of the material,its exact systematic position awaits further determination.The Zhulumlte Formation is a lithological unit in westerm Junggar,Xinjiang of northwest China and is mainly composed of conglomerates,pebbly sandstones and medium-to coarse-grained sandstones,with typical braided stream lithofacies.Channel-fill deposits are thick,with well-developed parallel bedding,scour structure,and large-scale trough,wedge and tabular cross-beddings.This part contains a large number of plant stem fossils in fragment.The fine-grained floodplain deposits are thin,with horizontal beddings and small sand ripple beddings;fine fragments of plant stems or leaves can be seen in the siltstones.These characteristics indicate that the Zhulumute Formation in the Bulongguoer area was formed in the braided stream

关 键 词：盾皮鱼类 短胸节甲鱼类 布龙鱼 晚泥盆世 河流相 西准噶尔 

分 类 号：Q915[天文地球—古生物学与地层学]