Early Cambrian epibolic gastrulation: A perspective from the Kuanchuanpu Member, Dengying Formation, Ningqiang, Shaanxi, South China
Early Cambrian epibolic gastrulation: A perspective from the Kuanchuanpu Member, Dengying Formation, Ningqiang, Shaanxi, South China
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早寒武世外生原肠胚形成：来自陕西宁强灯影组宽川铺段的视角
DOI：
10.1016/j.gr.2011.04.003
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发表时间：
2011-11
影响因子：
6.1
通讯作者：
Xiaoyong Yao, Jian Han ＊, Guoxiang Jiao
中科院分区：
文献类型：
--
作者：
Xiaoyong Yao, Jian Han ＊, Guoxiang Jiao
寒武纪大爆发的特点是各种后生动物骨骼化石明显突然出现，身体和遗迹化石的复杂性都增加了。其中，中国南部宁强登营组下寒武统宽川铺组的蛋和胚胎化石为后生动物个体发育研究提供了独特的窗口。原肠分裂是细胞分裂后的迁移阶段，可以看作是原生动物向后生动物过渡的胚胎阶段。例如，由于覆盖在体表上的星状刺，与以Olivooids为代表的胚胎阶段和以P.emeisis为代表的生长阶段相同，因此对峨眉斑点鱼的胚胎发育序列有很好的记载。虽然Olivooids被认为是分类上的混合体，但对其变异的考虑却被忽视了。鉴定了一种特殊类型的胚胎，其具锯齿形胚孔嘴唇，不同于典型的峨眉后生动物候选胚胎；其原肠形成过程被重建，并与现存的后生动物的外胚原肠形成相类似。这种“类型”的胚胎和成体都表现出径向对称，这表明了一种与棘皮动物截然不同的亲和力。此外，在早寒武世“小壳化石”(SSF‘s)中广泛见到的五径向对称的身体平面可能深深植根于埃迪卡拉纪。
The Cambrian explosion is marked by the apparent sudden appearance of diverse metazoan skeletal fossils and an increase in the complexity of both body and trace fossils. Among them, fossil eggs and embryos from the Lower Cambrian Kuanchuanpu Member of the Dengying Formation at Ningqiang in southern China provide a unique window for investigating the ontogeny of metazoans. Gastrulation is the cell migration stage after cleavage, and can be viewed as the embryonic analog of the transition from protozoan to metazoan grades of complexity. As an example, the embryonic developmental sequences of Punctatus emeiensis is well-documented because of the stellate spines covering the body surface, that are shared with embryonic stages represented by Olivooides and their growth stages represented by P. emeiensis. Although Olivooides was considered to be a taxonomic mixture, consideration of its variation was neglected. A specific type of embryo with zigzag blastopore lips that differs from typical candidate embryos for P. emeiensis is identified; its gastrulation process is reconstructed and is comparable to the epibolic gastrulation of extant metazoans. Both the embryos and adults of this ‘type’ display radial symmetry, that suggests an affinity distinct from that of echinoderms. Moreover, the body plan of penta-radial symmetry seen widely in Early Cambrian ‘Small Shelly Fossils’ (SSF's) was probably deep rooted in the Ediacaran.
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影响因子：
64.8
作者：
S. Morris;John S. Peel;A. K. Higgins;N. J. Soper;N. C. Davis
通讯作者：
S. Morris;John S. Peel;A. K. Higgins;N. J. Soper;N. C. Davis
影响因子：
6.1
作者：
J. Meert;B. Lieberman
通讯作者：
J. Meert;B. Lieberman
DOI：
--
发表时间：
1997
期刊：
--
影响因子：
--
作者：
S. Gilbert
通讯作者：
S. Gilbert
DOI：
10.1666/0022-3360(2000)074
发表时间：
2000-09
期刊：
--
影响因子：
--
作者：
S. Xiao;A. Knoll
通讯作者：
S. Xiao;A. Knoll
影响因子：
1.5
作者：
D. Stephen;B. David;Jun‐yuan Chen;O. Paola;Gao Feng;Lin Chia‐wei
通讯作者：
D. Stephen;B. David;Jun‐yuan Chen;O. Paola;Gao Feng;Lin Chia‐wei