TY - GEN AB - Heterotrophic protists are vital in Earth’s ecosystems, influencing carbon and nutrient cycles and occupying key positions in food webs as microbial predators. Fossils and molecular data suggest the emergence of predatory microeukaryotes and the transition to a eukaryote-rich marine environment by 800 million years ago (Ma). Neoproterozoic vase-shaped microfossils (VSMs) linked to Arcellinida testate amoebae represent the oldest evidence of heterotrophic microeukaryotes. This study explores the phylogenetic relationship and divergence times of modern Arcellinida and related taxa using a relaxed molecular clock approach. We estimate the origin of nodes leading to extant members of the Arcellinida Order to have happened during the latest Mesoproterozoic and Neoproterozoic (1054 to 661 Ma), while the divergence of extant infraorders postdates the Silurian. Our results demonstrate that at least one major heterotrophic eukaryote lineage originated during the Neoproterozoic. A putative radiation of eukaryotic groups (e.g., Arcellinida) during the early-Neoproterozoic sustained by favorable ecological and environmental conditions may have contributed to eukaryotic life endurance during the Cryogenian severe ice ages. Moreover, we infer that Arcellinida most likely already inhabited terrestrial habitats during the Neoproterozoic, coexisting with terrestrial Fungi and green algae, before land plant radiation. The most recent extant Arcellinida groups diverged during the Silurian Period, alongside other taxa within Fungi and flowering plants. These findings shed light on heterotrophic microeukaryotes’ evolutionary history and ecological significance in Earth’s ecosystems, using testate amoebae as a proxy. AD - University of São Paulo, São Paulo, Brazil ; Mississippi State University, MS, USA AD - Mississippi State University, MS, USA ; Texas Tech University, Lubbock, TX, USA AD - University of São Paulo, São Paulo, Brazil ; São Paulo State University, Rio Claro, Brazil AD - University of São Paulo, São Paulo, Brazil AD - Mississippi State University, MS, USA AD - University of Cologne, Cologne, Germany AD - Dalhousie University, Halifax, NS, Canada ; University of Victoria, Victoria, BC, Canada AD - Mississippi State University, MS, USA AD - University of São Paulo, São Paulo, Brazil AD - Mississippi State University, MS, USA AD - Mississippi State University, MS, USA AD - School of Viticulture and Enology, HES-SO University of Applied Sciences and Arts Western Switzerland AD - Mississippi State University, MS, USA AD - University of São Paulo, São Paulo, Brazil AU - Porfirio-Sousa, Alfredo L. AU - Tice, Alexander K. AU - Morais, Luana AU - Ribeiro, Giulia M. AU - Blandenier, Quentin AU - Dumack, Kenneth AU - Eglit, Yana AU - Fry, Nicholas W. AU - Souza, Maria Beatriz Gomes AU - Henderson, Tristan C. AU - Kleitz-Singleton, Felicity AU - Singer, David AU - Brown, Matthew W. AU - Lahr, Daniel J. G. CY - USA DA - 2024-07 DO - 10.1073/pnas.2319628121 DO - DOI EP - e2319628121 ID - 14956 JF - Proceedings of the National Academy of Sciences KW - arcellinida KW - vase-shaped microfossils KW - phylogenomics KW - ancestral state reconstruction KW - eukaryotic evolution L1 - https://arodes.hes-so.ch/record/14956/files/Porfirio-Sousa_2024_Amoebozoan_testate_amoebae_illuminate_the_diversity_of_heterotrophs.pdf L2 - https://arodes.hes-so.ch/record/14956/files/Porfirio-Sousa_2024_Amoebozoan_testate_amoebae_illuminate_the_diversity_of_heterotrophs.pdf L4 - https://arodes.hes-so.ch/record/14956/files/Porfirio-Sousa_2024_Amoebozoan_testate_amoebae_illuminate_the_diversity_of_heterotrophs.pdf LA - eng LK - https://arodes.hes-so.ch/record/14956/files/Porfirio-Sousa_2024_Amoebozoan_testate_amoebae_illuminate_the_diversity_of_heterotrophs.pdf N2 - Heterotrophic protists are vital in Earth’s ecosystems, influencing carbon and nutrient cycles and occupying key positions in food webs as microbial predators. Fossils and molecular data suggest the emergence of predatory microeukaryotes and the transition to a eukaryote-rich marine environment by 800 million years ago (Ma). Neoproterozoic vase-shaped microfossils (VSMs) linked to Arcellinida testate amoebae represent the oldest evidence of heterotrophic microeukaryotes. This study explores the phylogenetic relationship and divergence times of modern Arcellinida and related taxa using a relaxed molecular clock approach. We estimate the origin of nodes leading to extant members of the Arcellinida Order to have happened during the latest Mesoproterozoic and Neoproterozoic (1054 to 661 Ma), while the divergence of extant infraorders postdates the Silurian. Our results demonstrate that at least one major heterotrophic eukaryote lineage originated during the Neoproterozoic. A putative radiation of eukaryotic groups (e.g., Arcellinida) during the early-Neoproterozoic sustained by favorable ecological and environmental conditions may have contributed to eukaryotic life endurance during the Cryogenian severe ice ages. Moreover, we infer that Arcellinida most likely already inhabited terrestrial habitats during the Neoproterozoic, coexisting with terrestrial Fungi and green algae, before land plant radiation. The most recent extant Arcellinida groups diverged during the Silurian Period, alongside other taxa within Fungi and flowering plants. These findings shed light on heterotrophic microeukaryotes’ evolutionary history and ecological significance in Earth’s ecosystems, using testate amoebae as a proxy. PB - PNAS PP - USA PY - 2024-07 SN - 0027-8424 SP - e2319628121 T1 - Amoebozoan testate amoebae illuminate the diversity of heterotrophs and the complexity of ecosystems throughout geological time TI - Amoebozoan testate amoebae illuminate the diversity of heterotrophs and the complexity of ecosystems throughout geological time UR - https://arodes.hes-so.ch/record/14956/files/Porfirio-Sousa_2024_Amoebozoan_testate_amoebae_illuminate_the_diversity_of_heterotrophs.pdf VL - 2024, 121 Y1 - 2024-07 ER -