瓮安生物群中的瓶状微化石

Vase-shaped Microfossils from Weng'an Biota

报道了产自贵州瓮安新元古代陡山沱期磷块岩中的瓶状微化石2属3种,进一步证实瓮安生物群中已具有最早的能分泌硬体的原生动物存在。通过对这些瓶状微化石的立体形态、岩石薄片中的切面形态及外壁结构研究,认为瓮安生物群中的瓶状微化石在外壁具单层或多层结构,壳壁成分为磷酸钙质等特点,与陕南宽川铺生物群中的瓶状微化石相类似,但在化石的大小和外形特征方面又与高家山生物群中的瓶状微化石非常一致。这些化石的发现不仅进一步丰富了瓮安生物群的内容,而且为探讨具分泌硬体能力的原生动物的起源、分布和早期演化提供了新材料。

Some vase-shaped microfossils from the late Neoproterozoic Doushantuo phosphorites of Guizhou Province, South China, are reported. The vase-shaped microfossils are morphologically attributed to two genera and three species. They resemble to the vase-shaped naicrofossils from the Early Cambrian Kuanchuanpu biota of southern Shaanxi Province in terms of the rnicrostructure and chemical components of the fossil walls. Microscopic observation indicates that the walls of the vase-shaped fossils from both Weng＇ an biota and Kuanchuanpu biota are of either Single-layer or multilayers, and of calcium phosphate in chemical composition. Also, the vase-shaped fossils show some close similarities in size and general contour to the vase-shaped fossils from Neoproterozoic Gaojiashan biota. The discovery of the vaseshaped microfossils from the Doushantuo phosphorite may not only enrich our knowledge of the Neoproterozoic protozoans in the Weng＇an biota, but also throw much light on the early evolution and diversification of protests of the boundary between Precambrianand Cambrian .