关山生物群龙宝山古虫（Vetulicola longbaoshanensis）再研究
发布时间：2018-11-20 10:47
【摘要】：古虫动物门是寒武纪最独特、最神秘的动物类群之一,后口动物起源之谜可追溯至这一生物类群,因此古虫类颇受古生物学家重视。位于我国云南东部的寒武系第二统第四阶的关山生物群中古虫动物化石丰富,目前已报道了古虫动物的3个种,龙宝山古虫(Vetulicola longbaoshanensis Yang et al.,2010)是其中之一。本文研究了关山生物群昆明高楼房剖面和武定兴隆村剖面中保存较完好的龙宝山古虫Vetulicola longbaoshanensis化石,并对其鳃部构造做了详细描述。龙宝山古虫V.longbaoshanensis鳃部构造比澄江生物群中古虫属的鳃部构造更加复杂,鳃囊呈葫芦状,由前小后大的两个囊状构造组成。在两个囊状构造的连接处,能观察到明显的鳃裂和浓密的鳃丝。此外,通过对比关山生物群中和澄江生物群中古虫类的前体长高比和鳃囊在前体的位置,本次研究还发现关山生物群中的古虫动物和澄江生物群方口古虫(Vetulicola rectangulata Luo et Hu,1999)在形态上极为相似,推测关山生物群中的古虫类由方口古虫(V.rectangulata)演化而来。同时,与澄江生物群中的方口古虫动物相比,关山生物群中的古虫动物的体型较大,前体长高比增加,鳃囊也随之增大。这表明古虫在激烈的生态竞争过程中已经淘汰了个体较小的类型,也从一个侧面反映了体型逐步增大是古虫类在寒武纪的一个演化趋势。
[Abstract]:The phylum Paleocephala is one of the most unique and mysterious fauna of the Cambrian. The origin mystery of hind mouth animal can be traced back to this biological group, so paleosperm has been paid much attention to by paleontologists. The fourth order of the Cambrian biota of the Cambrian in the eastern part of Yunnan Province is rich in fossils of Paleozoa fauna. Three species of Paleozoa have been reported at present, among which the (Vetulicola longbaoshanensis Yang et al.,2010 of Longbaoshan is one of them. In this paper, the well-preserved Vetulicola longbaoshanensis fossils of ancient worms in Guanshan biota, Kunming Gaoding and Xinglongcun, Wuding, are studied, and the Gill structure of them is described in detail. The Gill structure of V.longbaoshanensis in Longbaoshan is more complicated than that of Paleoptera in Chengjiang. The Gill sac is cucurbit-shaped and consists of two large structures. Obvious branchial cleft and dense branchial filaments can be observed at the junction of two cystic structures. In addition, by comparing the ratio of length to height of the forebody of Guanshan biota and Chengjiang biota, and the location of Gill sac in the precursor, the study also found that the paleoinsects in Guanshan biota and the (Vetulicola rectangulata Luo et Hu, in Chengjiang biota were found in this study. 1999) the morphology of Guanshan Biota is very similar. It is inferred that the paleoinsects in Guanshan biota evolved from V.rectangulata. At the same time, compared with Chengjiang biota, Guanshan biota has a larger size, higher ratio of precursor length to height, and larger Gill sac. This indicates that the palaeoworms have eliminated the smaller types of individuals in the fierce ecological competition, which also reflects that the gradual enlargement of the palaeosperm is an evolutionary trend of the Palaeodes in the Cambrian period.
【学位授予单位】：西北大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：Q915
，
本文编号：2344696
[Abstract]:The phylum Paleocephala is one of the most unique and mysterious fauna of the Cambrian. The origin mystery of hind mouth animal can be traced back to this biological group, so paleosperm has been paid much attention to by paleontologists. The fourth order of the Cambrian biota of the Cambrian in the eastern part of Yunnan Province is rich in fossils of Paleozoa fauna. Three species of Paleozoa have been reported at present, among which the (Vetulicola longbaoshanensis Yang et al.,2010 of Longbaoshan is one of them. In this paper, the well-preserved Vetulicola longbaoshanensis fossils of ancient worms in Guanshan biota, Kunming Gaoding and Xinglongcun, Wuding, are studied, and the Gill structure of them is described in detail. The Gill structure of V.longbaoshanensis in Longbaoshan is more complicated than that of Paleoptera in Chengjiang. The Gill sac is cucurbit-shaped and consists of two large structures. Obvious branchial cleft and dense branchial filaments can be observed at the junction of two cystic structures. In addition, by comparing the ratio of length to height of the forebody of Guanshan biota and Chengjiang biota, and the location of Gill sac in the precursor, the study also found that the paleoinsects in Guanshan biota and the (Vetulicola rectangulata Luo et Hu, in Chengjiang biota were found in this study. 1999) the morphology of Guanshan Biota is very similar. It is inferred that the paleoinsects in Guanshan biota evolved from V.rectangulata. At the same time, compared with Chengjiang biota, Guanshan biota has a larger size, higher ratio of precursor length to height, and larger Gill sac. This indicates that the palaeoworms have eliminated the smaller types of individuals in the fierce ecological competition, which also reflects that the gradual enlargement of the palaeosperm is an evolutionary trend of the Palaeodes in the Cambrian period.
【学位授予单位】：西北大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：Q915
，
本文编号：2344696
本文链接：https://www.wllwen.com/kejilunwen/diqiudizhi/2344696.html
