Vase‐Shaped Microfossils From North China Suggest an Earlier Origin of Protozoa at ~1.56 Ga

ABSTRACT

The transition of body structure from soft body to hard body is the milestone event in the evolution of early eukaryotes. In this paper, we report some of the earliest Vase‐shaped microfossils (VSMs) from the calcareous shale intervals in the ~1.56 Ga Gaoyuzhuang Formation of North China. These VSMs are interpreted as possible testate amoebae in affinity and may represent the earliest fossil record of unicellular heterotrophic protozoa with the ability of test building so far. Palaeoecologically, the finding of the Gaoyuzhuang VSMs likely indicates that the three‐level energy pyramid composed of producer–decomposer–primary consumer in the food chain may have already been established in the early Mesoproterozoic oceans.