Amoebozoa

(Lühe 1913) sensu Cavalier-Smith 1998

Amoebozoans evolved from their last common ancestor around 1.2 billion years ago. It appears that amoebozoans originally were sexual, ciliated and able to create a sporocarpic fruiting body. Through evolutionary patters most of todays amoebozoans have lost some of these abilities and have a less complex life cycle, most often asexual. Almost all taxa display amoeboid activity in all or in certain stages of their life cycle. Amoeboid locomotion with steady flow of the cytoplasm or occasional eruptions in some groups; alternatively, amoeboid locomotion involving the extension and retraction of pseudopodia and/or subpseudopodia with little coordinated movement of the cytoplasm. Cells naked, often with well-developed, differentiated glycocalyx or in several groups acovered with a tectum or a cuticle. Two groups are testate, enclosed in a flexible or hard extracellular envelope with one to several openings. Many taxa exhibit either sporocarpic or sorocarpic fruiting. Biciliated, uniciliated, or multiciliated stages in the life cycle of some taxa; some taxa exhibit reduction of the bikont kinetid to a unikont kinetid.

Amoebozoa is devided into 3 major linages, Tubulinea, Evosea, and Discosea.

● Tubulinea

Smirnov, Nassonova, Berney, Fahrni, Bolivar et Pawlowski 2005

Organisms producing lobose pseudopodia (lobopodia). The entire cell or individual pseudopodia (in polypodial cells) are tubular, cylindrical, or subcylindrical, rounded in cross- section. If cells are flattened or branched they are capable of altering the locomotive form from a flattened, expanded one to monopodial or polypodial, with subcylindrical pseudopodia. Monoaxial flow of the cytoplasm in every pseudopodium or in the entire cell. No ciliate stages. Two groups are testate, and two sorocarpic taxa are known. No sporocarpy has been reported.

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Amoeba proteus

● Evosea

Kang et al. 2017

Representatives of this clade can vary across almost the entire range of morphologies seen in Amoebozoa. Many members have complex life cycles that include amoeboid, ciliated and fruiting stages. Some species appear to be exclusively ciliated with no amoeboid features. Most taxa with only a subset of these life cycle stages.

● Discosea

(Cavalier-Smith et al. 2004) Smirnov et al. 2011

Flattened naked amoebae that never produce tubular, subcylindrial pseudopodia and never alter their locomotive form. Cytoplasmic flow polyaxial or without a pronounced axis. Subpseudopodia short or absent. Ciliated stages unknown; several taxa sporocarpic.

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