现代丰年虾卵的腐解实验——对早期化石胚胎研究的启示

DECOMPOSITION EXPERIMENT ON EMBRYOS OF ARTEMIA SALINA(CRUSTACEA)——AN ENLIGHTENMENT ON THE EARLY PHOSPHATIZED FOSSIL EMBRYOS

早寒武世和埃迪卡拉纪中的球状化石,一些已被归入可能的后生动物胚胎化石,由于具较为完好的三维保存方式以及近乎完美的胚胎发育序列,为早期后生动物的起源、分类、谱系演化及发育生物学提供了难得的实证材料。然而随着研究的深入,多数寒武纪胚胎的生物学分类位置未定;而数量异常巨大、又有独自的保存方式的晚元古代陡山沱组胚胎的真伪和生物学归属,更是争议未消。通过对现生生物胚胎的实验埋藏研究,可以揭示出各类生物胚胎在腐解、埋藏各阶段的保存潜力,而现代胚胎在各实验埋藏阶段形态、结构的变化,也能为化石胚胎的研究提供重要的实证材料。本文就是通过对虾卵胚胎各发育阶段腐解保存潜力的实验模拟研究,试图为球状化石的形成机制和化石归属提供一些实验室依据。

Some phosphatized and silicified spherical fossils from the Ediacaran Doushantuo Formation and Early Cambrian Kuanchuanpu Formation have been classified as possible metazoan embryo fossils.With the intact three-dimension structure preservation and perfect sequence of embryonic development,those fossils provide rare empirical evidence for the study of origination,classification,lineage evolutionary and developmental biology of early metazoa.The study of embryonic fossils has become one of the fastest developing discipline in the past 20 years.However,the biological classification of majority Cambrian embryo remain uncertain;whileas,the authenticity and biological attribution of the unusually preserved embryos in the Neoproterozoic Doushantuo Formation are still in heated controversy.The simulation experiments on modern embryo decomposition Artemia salina（brine shrimp）may throw a new light to solve those problems.Through the simulated taphonomic experiment of living embryos,their preservational potentials at every stage of the decomposition,disaggregation,burial and diagenesis can be well explored,and important empirical material can also be provided to study the fossil embryos by the variation of morphologies and structures of modern embryos in each experiment phases.This study mainly focus on the decomposition changes in various developing stages of the brine shrimp embryos to detect similarities and differences in morphology,structure and texture between modern embryos in different experimental phases and those of the Doushantuo stage and the Early Cambrian.