The Changcheng System is a

Mesoproterozoic The Mesoproterozoic Era is a geologic era that occurred from . The Mesoproterozoic was the first era of Earth's history for which a fairly definitive geological record survives. Continents existed during the preceding era (the Paleoproterozoic ...

geological formation which has yielded primitive fossil

eukaryotes The eukaryotes ( ) constitute the domain of Eukaryota or Eukarya, organisms whose cells have a membrane-bound nucleus. All animals, plants, fungi, seaweeds, and many unicellular organisms are eukaryotes. They constitute a major group of ...

, such as '' Tappania''. It formed around 1.9-1.8 billion years ago as a result of a continental collision in the North China Craton.

References

Mesoproterozoic geology Geologic formations of China {{China-geologic-formation-stub