Megascopic Multicellular Organisms from the 1700-Million-Year-Old Tuanshanzi Formation in the Jixian Area, North China

Hundreds of specimens of megascopic carbonaceous fossils shaped like leaves have been found at the ∼1700-million-year-old Tuanshanzi Formation of the uppermost Paleoproterozoic Changcheng Group (1600 to 1850 million years old) in the Jixian area, north China. These leaflike fossils mostly resemble the Longfengshania ; each consists of a blade (with spoonlike, lanceolate, or ribbonlike shapes) with a single stipe, a holdfast, or both. On the basis of their megascopic dimensions, preliminary differentiation of organs or tissues, and possible remains of multicellular structures, they are benthic, multicellular algal fossils similar to the longfengshanids. These fossils indicate that multicellular organisms originated at least 1700 million years ago.