论文部分内容阅读
华南伊迪卡拉系陡山沱组保存的磷酸盐化球状化石中有一部分被认为是最早的后生动物胚胎化石,但由于缺乏成年或幼年过渡期的化石证据,对这些最早微化石的动物属性还一直存在争议。最近在贵州江口县翁会地区伊迪卡拉(震旦)系陡山沱组的页岩中发现一个与“庙河生物群”相似的宏体碳质压膜化石群,其中包含一个盘状的宏体化石新类型——八臂仙母虫(Eoandromeda octobrachiata,Tang et al.2008),具有八条螺旋状辐射的旋臂,封闭在一个包膜内。这种八辐射结构在八射珊瑚和栉水母动物中都可见到,但同时具有的螺旋特性与现生的所有类群都无法对比。在贵州陡山沱组的“瓮安生物群”中发现的球状胚胎化石同样具有螺旋性状,尽管还没有直接的个体发育证据,但我们认为新属种可能代表这些螺旋状胚胎化石的成年实体化石。最新报道的南澳大利亚Rawnsley石英岩层中也发现相似的印痕化石,被归为同一类别,表明华南的“庙河生物群”与澳大利亚的“伊迪卡拉生物群”时代相当。翁会化石库中少量出露的三辐射化石与俄罗斯“白海生物群”的典型分子—Albumares和Anfesta可以对比。新发现的倾斜保存的八臂仙母虫化石和碳质条带呈子午线状排列的核桃状化石,可能是该类化石归属栉水母类的有力证据,这一发现推测可将栉水母类的最早化石记录从“澄江生物群”的早寒武世推前大约3千万年。
Some of the phosphated spherical fossils preserved in the Doushantuo Formation in southern China are considered to be the earliest embryonic fossils of embryo zooplankton but due to the lack of fossil evidence during the transitional period of adult or juvenile, There has been controversy. Recently a macro-carbonaceous lamination fossil group similar to that of the “Miahe biota” has been found in the shale of the Dimalshutuo Formation in the Ediacaran (Eden) area of the Wenghui area, Jiangkou County, Guizhou Province, which contains a disk New macro-fossil fossils - Eighth armor (Eoandromeda octobrachiata, Tang et al. 2008), a spiral arm with eight helical radiations enclosed in a capsule. This eight-radiation structure is visible in both octopus and cercaria, but at the same time has a spiral characteristic that is not comparable to any of the existing taxa. The globular embryonic fossils found in the Weng’an biota in the Doushantuo Formation in Guizhou also have the same helical traits. Although there is no direct evidence of individual development, we believe the new species may represent the adult of these spiral-shaped embryos Physical fossils. Similar reports of similar Indian mark fossils have also been found in the newly reported quartz rocks of Rawnsley, South Australia, as belonging to the same category, indicating that the “Miao River Biota” in South China is comparable to the “Idiacara Biota” era in Australia. The three exposed fossils of the Wenghui fossil reservoir are comparable to those of Albumares and Anfesta, typical of the Russian “White Sea Biota”. The newly discovered preserved preserved eight-legged fawn fossils and carbonaceous bands in a radial arrangement of walnut-like fossils may be strong evidence of such fossils attributed to comb Jellyfish, this finding presumably can comb the ear of jellyfish The fossil record was pushed forward about 30 million years from the Early Cambrian of the “Chengjiang Biota.”