information:highlighting, structural:reformatting
Neoproterozoic

Modern eukaryotes began to appear abundantly in the Tonian period (1000–720 Ma), fueled by the proliferation of red algae. The oldest fossils assigned to modern eukaryotes belong to two photosynthetic protists: the multicellular red alga Bangiomorpha (from 1050 Ma), and the chlorophyte green alga Proterocladus (from 1000 Ma). Abundant fossils of heterotrophic protists appear later, around 900 Ma, with the emergence of fungi. For example, the oldest fossils of Amoebozoa are vase-shaped microfossils resembling modern testate amoebae, found in 800 million-year-old rocks. Radiolarian shells are found abundantly in the fossil record after the Cambrian period (~500 Ma), but more recent paleontological studies are beginning to interpret some Precambrian fossils as the earliest evidence of radiolarians.