Obsolete eukaryote taxa

A protist ( ) or protoctist is any eukaryotic organism that is not an animal, land plant, or fungus. Protists do not form a natural group, or clade, but are a paraphyletic group encompassing the entire eukaryote tree of life, from which land plants, animals, and fungi evolved. They are primarily single-celled, exhibiting a wide range of forms such as amoebae, ciliates, thick-walled microalgae and, more commonly, flagellates. Several transitions to multicellularity have occurred among protists, from colonies with alternating cell types to giant slime molds, fungus-like organisms, and seaweeds w

Chromista is a proposed but controversial biological kingdom, refined from the Chromalveolata, consisting of single-celled and multicellular eukaryotic species that share similar features in their photosynthetic organelles (plastids). It includes all eukaryotes whose plastids contain chlorophyll c and are surrounded by four membranes. If the ancestor already possessed chloroplasts derived by endosymbiosis from red algae, all non-photosynthetic Chromista have secondarily lost the ability to photosynthesise. Its members might have arisen independently as separate evolutionary groups from the las

Chromalveolata was a eukaryote supergroup present in a major classification of 2005, then regarded as one of the six major groups within the eukaryotes. It was a refinement of the kingdom Chromista, first proposed by Thomas Cavalier-Smith in 1981. Chromalveolata was proposed to represent the organisms descended from a single secondary endosymbiosis involving a red alga and a bikont. The plastids in these organisms are those that contain chlorophyll c.

Heliozoa, commonly known as sun-animalcules, are microbial eukaryotes (protists) with stiff arms (axopodia) radiating from their spherical bodies, which are responsible for their common name. The axopodia are microtubule-supported projections from the amoeboid cell body, and are variously used for capturing food, sensation, movement, and attachment. They are similar to Radiolaria, but they are distinguished from them by lacking central capsules and other complex skeletal elements, although some produce simple scales and spines. They may be found in both freshwater and marine environments.

thumb | right | alt=An illustration of various creature in a water drop | Illustration of a water drop from stagnant water Infusoria is a word used to describe various freshwater microorganisms, including ciliates, copepods, euglenoids, planktonic crustaceans, protozoa, unicellular algae and small invertebrates. Some authors (e.g., Bütschli) have used the term as a synonym for Ciliophora. In modern, formal classifications, the term is considered obsolete; the microorganisms previously and colloquially referred to as Infusoria are mostly assigned to the clades Diaphoretickes (e.g. ciliates, mos

The phylum Sarcomastigophora belongs to the Protista or protoctista kingdom and it includes many unicellular or colonial, autotrophic, or heterotrophic organisms. It is characterized by flagella, pseudopodia, or both.

In biology, Archezoa is a term that has been introduced by several authors to refer to a group of organisms (a taxon). Authors include Josef Anton Maximilian Perty, Ernst Haeckel and in the 20th century by Thomas Cavalier-Smith in his classification system. Each author used the name to refer to categories of organisms described by different sets of shared characteristics. This reuse by later authors of the same taxon name for different groups of organisms is problematic in taxonomy because the inclusion of the name in a sentence such as "Archezoa have no olfactory organs" does not make sense u

The Apusozoa are a paraphyletic phylum of flagellate eukaryotes. They are usually around 5–20 μm in size, and occur in soils and aquatic habitats, where they feed on bacteria. They are grouped together based on the presence of an organic shell or theca under the dorsal surface of the cell.

Biliphyta is an obsolete polyphyletic subkingdom of algae.

The order Pennales is a proposed traditional subdivision of the heterokont algae known as diatoms. The order is named for the shape of the cell walls (or valves or frustules) of pennate diatoms, which are elongated in valve view. The valves may be linear or oval in shape, and usually bear bilaterally symmetrical ornamental patterns. These patterns are composed of a series of transverse lines (known as striae) that can appear as rows of dots when viewed with an optical microscope. Some pennate diatoms also exhibit a fissure along their longitudinal axis. This is known as a raphe, and is involve

thumb|300px|Evolution of the algae, as depicted by Thomas Cavalier-Smith in 2002. Neither the tree's structure nor some of the terms in the diagram reflect a modern consensus.

thumb|Holotrich, Frontonia leucas, by Schewiakoff, from Gary N. Calkins, The Protozoa 1910 Holotricha was an order of ciliates. The classification has fallen from use as a formal taxon, but the terms "holotrich" and "holotrichous" are still applied descriptively to organisms with cilia of uniform length distributed evenly over the surface of the body.