1. Falkowski, P. G. et al. The evolution of modern eukaryotic phytoplankton. Science 305, 354–360 (2004).

2. Keeling, P. J. The number, speed, and impact of plastid endosymbioses in eukaryotic evolution. Annu. Rev. Plant Biol. 64, 583–607 (2013).

3. Brocks, J. J. et al. The rise of algae in Cryogenian oceans and the emergence of animals. Nature 548, 578–581 (2017).

4. Knoll, A. H., Summons, R. E., Waldbauer, J. R. & Zumberge, J. E. in Evolution of Primary Producers in the Sea (eds Falkowski, P. G. & Knoll, A. H.) 133–163 (Academic Press, 2007).

5. Parfrey, L. W., Lahr, D. J. G., Knoll, A. H. & Katz, L. A. Estimating the timing of early eukaryotic diversification with multigene molecular clocks. Proc. Natl Acad. Sci. USA 108, 13624–13629 (2011).

6. Sánchez-Baracaldo, P., Raven, J. A., Pisani, D. & Knoll, A. H. Early photosynthetic eukaryotes inhabited low-salinity habitats. Proc. Natl Acad. Sci. USA 114, E7737–E7745 (2017).

7. Gibson, T. M. et al. Precise age of Bangiomorpha pubescens dates the origin of eukaryotic photosynthesis. Geology 46, 135–138 (2017).

8. Fučíková, K. et al. New phylogenetic hypotheses for the core Chlorophyta based on chloroplast sequence data. Front. Ecol. Evol. 2, 63 (2014).

9. Jackson, C., Knoll, A. H., Chan, C. X. & Verbruggen, H. Plastid phylogenomics with broad taxon sampling further elucidates the distinct evolutionary origins and timing of secondary green plastids. Sci. Rep. 8, 1523 (2018).

10. Del Cortona, A. et al. Neoproterozoic origin and multiple transitions to macroscopic growth in green seaweeds. Proc. Natl Acad. Sci. USA https://doi.org/10.1073/pnas.1910060117 (2020).

11. Berney, C. & Pawlowski, J. A molecular time-scale for eukaryote evolution recalibrated with the continuous microfossil record. Proc. R. Soc. B. 273, 1867–1872 (2006).

12. Verbruggen, H. et al. A multi-locus time-calibrated phylogeny of the siphonous green algae. Mol. Phylogenet. Evol. 50, 642–653 (2009).

13. Morris, J. L. et al. The timescale of early land plant evolution. Proc. Natl Acad. Sci. USA 115, E2274–E2283 (2018).

14. Bengtson, S., Sallstedt, T., Belivanova, V. & Whitehouse, M. Three-dimensional preservation of cellular and subcellular structures suggests 1.6 billion-year-old crown-group red algae. PLoS Biol. 15, e2000735 (2017).

15. Betts, H. C. et al. Integrated genomic and fossil evidence illuminates life’s early evolution and eukaryote origin. Nat. Ecol. Evol. 2, 1556–1562 (2018).

16. Xiao, S. et al. The Weng’an biota and the Ediacaran radiation of multicellular eukaryotes. Natl Sci. Rev. 1, 498–520 (2014).

17. Butterfield, N. J., Knoll, A. H. & Swett, K. Paleobiology of the Neoproterozoic Svanbergfjellet formation, Spitsbergen. Fossils Strata 34, 1–84 (1994).

18. Graham, L. E. Digging deeper: why we need more Proterozoic algal fossils and how to get them. J. Phycol. 55, 1–6 (2019).

19. Marshall, C. R. Confidence intervals on stratigraphic ranges. Paleobiology 16, 1–10 (1990).

20. Zumberge, J. A., Rocher, D. & Love, G. D. Free and kerogen-bound biomarkers from late Tonian sedimentary rocks record abundant eukaryotes in mid-Neoproterozoic marine communities. Geobiology https://doi.org/10.1111/gbi.12378 (2019).

21. Gueneli, N. et al. 1.1-billion-year-old porphyrins establish a marine ecosystem dominated by bacterial primary producers. Proc. Natl Acad. Sci. USA 115, E6978–E6986 (2018).

22. Hoshino, Y. et al. Cryogenian evolution of stigmasteroid biosynthesis. Sci. Adv. 3, e1700887 (2017).

23. Zhang, S.-H., Zhao, Y., Ye, H. & Hu, G.-H. Early Neoproterozoic emplacement of the diabase sill swarms in the Liaodong Peninsula and pre-magmatic uplift of the southeastern North China Craton. Precambrian Res. 272, 203–225 (2016).

24. Bureau of Geology and Mineral Resources of Liaoning Province Regional Geology of Liaoning Province Chinese Ministry of Geology and Mineral Resources, Geological Memoirs, Series 1, No. 5 (Geological Publishing House, 1989).

25. Yang, D.-B. et al. U-Pb ages and Hf isotope data from detrital zircons in the Neoproterozoic sandstones of northern Jiangsu and southern Liaoning Provinces, China: implications for the late Precambrian evolution of the southeastern North China Craton. Precambrian Res. 216–219, 162–176 (2012).

26. Zhao, H. et al. New geochronologic and paleomagnetic results from early Neoproterozoic mafic sills and late Mesoproterozoic to early Neoproterozoic successions in the eastern North China Craton, and implications for the reconstruction of Rodinia. Geol. Soc. Am. Bull. https://doi.org/10.1130/B35198.1 (2019).

27. Pascher, A. Uber Flagellaten und Algen. Ber. Dtsch. Bot. Ges. 32, 136–160 (1914).

28. Mattox, K. R. & Stewart, K. D. in Systematics of the Green Algae (eds Irvine, D. E. G. & John, D. M.) 29–72 (Academic Press, 1984).

29. Oltmanns, F. Morphologie und Biologie der Algen Vol. 1 (Gustav Fischer, 1904).

30. Zhao, Z.-J., Zhu, H., Liu, G.-X. & Hu, Z.-Y. Rhizoclonium ramosum sp. nov. (Cladophorales, Chlorophyta), a new freshwater algal species from China. Fottea (Praha) 16, 12–21 (2016).

31. Zhu, H. et al. Molecular phylogeny and morphological diversity of inland Cladophora (Cladophorales, Ulvophyceae) from China. Phycologia 57, 191–208 (2018).

32. Okuda, K. et al. Segregative cell division and the cytoskeleton in two species of the genus Struvea (Cladophorales, Ulvophyceae, Chlorophyta). Phycol. Res. 64, 219–229 (2016).

33. Leliaert, F. & Coppejans, E. A revision of Cladophoropsis Børgesen (Siphonocladales, Chlorophyta). Phycologia 45, 657–679 (2006).

34. Hermann, T. N. & Podkovyrov, V. N. A discovery of Riphean heterotrophs in the Lakhanda Group of Siberia. Paleontol. J. 44, 374–383 (2010).

35. Hermann, T. N. Filamentous microorganisms in the Lakhanda Formation on the Maya River. Paleontol. J. 1981, 100–107 (1981).

36. Nowak, H. et al. Filamentous eukaryotic algae with a possible cladophoralean affinity from the Middle Ordovician Winneshiek Lagerstätte in Iowa, USA. Geobios 50, 303–309 (2017).

37. Wellman, C. H. & Strother, P. K. The terrestrial biota prior to the origin of land plants (embryophytes): a review of the evidence. Palaeontology 58, 601–627 (2015).

38. Nagovitsin, K. E. et al. Revised Neoproterozoic and Terreneuvian stratigraphy of the Lena-Anabar Basin and north-western slope of the Olenek Uplift, Siberian Platform. Precambrian Res. 270, 226–245 (2015).

39. Xiao, S. & Tang, Q. After the boring billion and before the freezing millions: evolutionary patterns and innovations in the Tonian Period. Emerg. Top. Life Sci. 2, 161–171 (2018).

40. Fryxell, G. A. Survival Strategies of the Algae (Cambrian Univ. Press, 1983).

41. Komárek, J. & Johansen, J. R. in Freshwater Algae of North America 2nd edn (eds Wehr, J. D. et al.) 135–235 (Academic Press, 2015).

42. Bartley, J. K. Actualistic taphonomy of cyanobacteria: implications for the Precambrian fossil record. Palaios 11, 571–586 (1996).

43. Niklas, K. J. & Newman, S. A. The origins of multicellular organisms. Evol. Dev. 15, 41–52 (2013).

44. Roper, M., Ellison, C., Taylor, John, W. & Glass, N. L. Nuclear and genome dynamics in multinucleate ascomycete fungi. Curr. Biol. 21, R786–R793 (2011).

45. Randhawa, M. S. Akinete formation in Vaucheria geminata. Bot. Gaz. 103, 809–811 (1942).

46. Duffield, E. C. S., Waaland, S. D. & Cleland, R. Morphogenesis in the red alga, Griffithsia pacifica: regeneration from single cells. Planta 105, 185–195 (1972).

47. Deacon, J. Fungal Biology 4th edn (Blackwell Publishing, 1997).

48. Willetts, H. J. & Wong, A. L. Ontogenetic diversity of sclerotia of Sclerotinia sclerotiorum and related species. Trans. Br. Mycol. Soc. 57, 515–524 (1971).

49. Butterfield, N. J. A vaucheriacean alga from the middle Neoproterozoic of Spitsbergen: implications for the evolution of Proterozoic eukaryotes and the Cambrian explosion. Paleobiology 30, 231–252 (2004).

50. Graham, L. E. & Wilcox, L. E. Algae (Prentice-Hall, 2000).

51. Butterfield, N. J. Bangiomorpha pubescens n. gen., n. sp.: implications for the evolution of sex, multicellularity, and the Mesoproterozoic–Neoproterozoic radiation of eukaryotes. Paleobiology 26, 386–404 (2000).

52. Shih, P. M. & Matzke, N. J. Primary endosymbiosis events date to the later Proterozoic with cross-calibrated phylogenetic dating of duplicated ATPase proteins. Proc. Natl Acad. Sci. USA 110, 12355–12360 (2013).

53. Moczydlowska, M., Landing, E., Zang, W. & Palacios, T. Proterozoic phytoplankton and timing of Chlorophyte algae origins. Palaeontology 54, 721–733 (2011).

54. Butterfield, N. J. Proterozoic photosynthesis—a critical review. Palaeontology 58, 953–972 (2015).

55. Knoll, A. H. Paleobiological perspectives on early eukaryotic evolution. Cold Spring Harb. Perspect. Biol. 6, a016121 (2014).

56. Butterfield, N. J. Early evolution of the Eukaryota. Palaeontology 58, 5–17 (2015).

57. Leliaert, F. et al. Phylogeny and molecular evolution of the green algae. Crit. Rev. Plant Sci. 31, 1–46 (2012).

58. Fang, L., Leliaert, F., Zhang, Z.-H., Penny, D. & Zhong, B.-J. Evolution of the Chlorophyta: insights from chloroplast phylogenomic analyses. J. Syst. Evol. 55, 322–332 (2017).

59. Cocquyt, E., Verbruggen, H., Leliaert, F. & De Clerck, O. Evolution and cytological diversification of the green seaweeds (Ulvophyceae). Mol. Biol. Evol. 27, 2052–2061 (2010).

60. Umen, J. G. Green algae and the origins of multicellularity in the plant kingdom. Cold Spring Harb. Perspect. Biol. 6, a016170 (2014).

61. Butterfield, N. J. Oxygen, animals and aquatic bioturbation: an updated account. Geobiology 16, 3–16 (2018).

62. Gold, D. A. et al. Sterol and genomic analyses validate the sponge biomarker hypothesis. Proc. Natl Acad. Sci. USA 113, 2684–2689 (2016).

63. Zumberge, J. A. et al. Demosponge steroid biomarker 26-methylstigmastane provides evidence for Neoproterozoic animals. Nat. Ecol. Evol. 2, 1709–1714 (2018).

64. Bunt, J. S. in Primary Productivity of the Biosphere (eds Lieth, H. & Whittaker, R. H.) 169–183 (Springer, 1975).

65. Loron, C. C. et al. Early fungi from the Proterozoic era in Arctic Canada. Nature 570, 232–235 (2019).

66. Schuster, A. et al. Divergence times in demosponges (Porifera): first insights from new mitogenomes and the inclusion of fossils in a birth–death clock model. BMC Evol. Biol. 18, 114 (2018).

67. Cole, D. B. et al. A shale-hosted Cr isotope record of low atmospheric oxygen during the Proterozoic. Geology 7, 555–558 (2016).

68. Tang, Q. et al. Organic-walled microfossils from the early Neoproterozoic Liulaobei Formation in the Huainan region of North China and their biostratigraphic significance. Precambrian Res. 236, 157–181 (2013).

69. Tsutsui, I. et al. Ecological and morphological profile of floating spherical Cladophora socialis aggregations in central Thailand. PLoS ONE 10, e0124997 (2015).

70. Parial, D. & Pal, R. Biosynthesis of monodisperse gold nanoparticles by green alga Rhizoclonium and associated biochemical changes. J. Appl. Phycol. 27, 975–984 (2015).

71. Zhao, Z.-J., Zhu, H., Hu, Z.-Y. & Liu, G.-X. Occurrence of true branches in Rhizoclonium (Cladophorales, Ulvophyceae) and the reinstatement of Rhizoclonium pachydermum Kjellman. Phytotaxa 166, 273–284 (2014).