The article "Cryogenian Origins of Multicellularity in Archaeoplastida" explores the evolutionary origins of multicellularity in Archaeoplastida, a supergroup of eukaryotic algae that includes land plants. Using a revised molecular dataset and reassessment of the fossil record, the researchers infer a time-calibrated phylogeny of early archaeoplastid evolution. Their analysis identifies two clades of Viridiplantae and places Bryopsidales as sister to the Chlorophyceae. Molecular clock analysis suggests that Archaeoplastida originated in the late-Paleoproterozoic to early-Mesoproterozoic (1712 to 1387 Ma). Ancestral state reconstruction of cytometric features reveals that many independent origins of multicellularity span the Cryogenian, consistent with the Cryogenian multicellularity hypothesis. Multicellular rhodophytes emerged 902 to 655 Ma, while crown-Anydrophyta (Zygnematophyceae and Embryophyta) originated 796 to 671 Ma, aligning with the Cryogenian plant terrestrialization hypothesis. The study resolves the timetree of Archaeoplastida, with age estimates for ancestral multicellular archaeoplastids coinciding with the Cryogenian, supporting hypotheses that propose a role of Snowball Earth in plant evolution. The research provides insights into the evolutionary processes that led to the development of multicellularity and the colonization of land by early archaeoplastids, highlighting the potential influence of Cryogenian glaciations on these events.The article "Cryogenian Origins of Multicellularity in Archaeoplastida" explores the evolutionary origins of multicellularity in Archaeoplastida, a supergroup of eukaryotic algae that includes land plants. Using a revised molecular dataset and reassessment of the fossil record, the researchers infer a time-calibrated phylogeny of early archaeoplastid evolution. Their analysis identifies two clades of Viridiplantae and places Bryopsidales as sister to the Chlorophyceae. Molecular clock analysis suggests that Archaeoplastida originated in the late-Paleoproterozoic to early-Mesoproterozoic (1712 to 1387 Ma). Ancestral state reconstruction of cytometric features reveals that many independent origins of multicellularity span the Cryogenian, consistent with the Cryogenian multicellularity hypothesis. Multicellular rhodophytes emerged 902 to 655 Ma, while crown-Anydrophyta (Zygnematophyceae and Embryophyta) originated 796 to 671 Ma, aligning with the Cryogenian plant terrestrialization hypothesis. The study resolves the timetree of Archaeoplastida, with age estimates for ancestral multicellular archaeoplastids coinciding with the Cryogenian, supporting hypotheses that propose a role of Snowball Earth in plant evolution. The research provides insights into the evolutionary processes that led to the development of multicellularity and the colonization of land by early archaeoplastids, highlighting the potential influence of Cryogenian glaciations on these events.