Willman S
Uppsala University, Department of Earth Sciences, Palaeobiology, Villavägen 16, SE-752 36, Uppsala, Sweden.
Geobiology. 2009 Jan;7(1):8-20. doi: 10.1111/j.1472-4669.2008.00178.x.
Acritarchs are a group of organic-walled microfossils with unknown biological affinities. The wall ultrastructure of the unornamented, smooth Leiosphaeridia sp. and the acanthomorphic Gyalosphaeridium pulchrum from the Ediacaran Dey Dey Mudstone in the Officer Basin, South Australia, was studied by use of transmission and scanning electron microscopy, and transmitted light microscopy. The study of the ultrastructure reveals a complexity in the cell wall not seen in prokaryotes. Wall ultrastructures range from single-layered to three- or four-layered and from homogeneous to porous. Acritarchs with different wall ultrastructures may be different organisms, but may also reflect different stages in a life cycle. In this paper I review previous ultrastructure studies and discuss possible algal and metazoan affinities for the specimens studied herein.
疑源类是一类生物亲缘关系不明的有机壁微化石。利用透射电子显微镜、扫描电子显微镜和透射光显微镜，对南澳大利亚奥菲斯盆地埃迪卡拉纪代伊代伊泥岩中无纹饰、表面光滑的莱奥球藻属物种以及具刺形态的美丽球囊藻的壁超微结构进行了研究。超微结构研究揭示了原核生物中未见的细胞壁复杂性。壁超微结构从单层到三层或四层，从均质到多孔。具有不同壁超微结构的疑源类可能是不同的生物，但也可能反映生命周期中的不同阶段。在本文中，我回顾了以前的超微结构研究，并讨论了本文所研究标本可能的藻类和后生动物亲缘关系。
