Skeletogenesis and asexual reproduction in the earliest biomineralizing animal Cloudina
Skeletogenesis and asexual reproduction in the earliest biomineralizing animal Cloudina
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DOI：
10.1130/g21198.1
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发表时间：
2005-04-01
期刊：
影响因子：
5.8
通讯作者：
Xiao, SH
中科院分区：
文献类型：
--
作者：
Hua, H;Chen, Z;Xiao, SH
管状化石Cloudina正在成为重要的埃迪卡拉纪化石。然而，它的形态、骨骼发生、繁殖和系统发育亲缘关系还没有完全解决。来自中国南部灯影组的新材料证实，云母管由偏心的、有时深嵌套的漏斗组成，并且没有横向横壁，与传统的锥中锥形态重建不同。管壁由微米大小的、大致相等的晶体组成。许多云母管分叉，其中子体漏斗在母体漏斗中分裂。据解释，Cloudina动物能够在旧漏斗中启动新漏斗的生物矿化。它的骨架很可能是以悬浮在有机基质中的方解石晶体的形式分泌出来的；这些晶体似乎没有成核并生长在片状基质上。显然，它能够通过在双亲漏斗内萌发而不是在孔口末端进行无性繁殖。Cloudina的形态、骨骼发生和无性繁殖与现代锯齿纲环节动物大体相似，表明可能的系统发育关系或形态趋同。
The tubular fossil Cloudina is emerging as an important Ediacaran index fossil. However, its morphology, skeletogenesis, reproduction, and phylogenetic affinity have not been fully resolved. New material from the Dengying Formation of south China confirms that Cloudina tubes consist of eccentrically and sometimes deeply nested funnels and that the tubes lack transverse cross-walls, inconsistent with the traditional cone-in-cone morphological reconstruction. Tube walls are composed of micrometer-sized, more or less equant crystals. A number of Cloudina tubes branch dichotomously, in which daughter funnels split within parent ones. The Cloudina animal is interpreted to have been able to initiate biomineralization of new funnels within old ones. Its skeleton was probably secreted as calcite crystals suspended in organic matrix; the crystals do not appear to have nucleated and grown on a sheeted substrate. It was clearly capable of asexual reproduction, through budding within parent funnels rather than at the apertural end. The morphology, skeletogenesis, and asexual reproduction of Cloudina are broadly similar to modern serpulid annelids, indicating possible phylogenetic relationships or morphological convergence.