Excavata
Diverse group of unicellular flagellate eukaryotes, sometimes considered a clade.
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Abu Shawka · CC0
Excavata is a broad and varied grouping of single-celled eukaryotes, often considered a valid clade or informal group by many researchers. First proposed by Simpson and Patterson in 1999, the name was Latinized and given a formal taxonomic rank by Thomas Cavalier-Smith in 2002.
The group includes free-living and symbiotic protists, as well as notable human parasites like Giardia and Trichomonas. Excavates were once placed within the now-defunct kingdom Protista. They are regarded as a basal lineage of flagellates.
Quick Facts
- First suggested
- 1999 by Simpson and Patterson
- Latinized and assigned rank
- 2002 by Thomas Cavalier-Smith
- Group type
- Paraphyletic group of unicellular Eukaryota
- Key subgroups
- Discobids
- metamonads
- malawimonads
- Notable human parasites
- Giardia, Trichomonas
- Distinguishing feature
- Distinctive ultrastructural identity (ventral feeding groove)
Facts from the source article.
Background
Excavata was first proposed by Simpson and Patterson in 1999, and the name was latinized and given a taxonomic rank by Thomas Cavalier-Smith in 2002. The group was distinguished from other lineages based on electron-microscopic information about cell arrangement, specifically a distinctive ultrastructural identity.
Most excavates are unicellular, heterotrophic flagellates, with only some Euglenozoa being photosynthetic. Many have a conspicuous ventral feeding groove supported by microtubules, giving the organisms their name. However, various groups that lack these traits are considered derived excavates based on genetic evidence.
Frequently Asked Questions
What is Excavata known for?
Members of this group are distinguished by a characteristic ventral feeding groove in their ultrastructure, which is the feature the name references. They occupy a foundational position in the eukaryotic tree of life as early-diverging flagellates.
Who put Excavata on the map?
The name was first proposed by Simpson and Patterson in 1999, and it was later Latinized and assigned a formal taxonomic rank by Thomas Cavalier-Smith in 2002. Before that, excavate organisms were simply lumped into the now-abolished kingdom Protista.
More in Higher-Level Taxonomy & Evolution
Sources
Compiled from Wikipedia and the sources listed below. Text from Wikipedia is available under CC BY-SA 4.0; this entry is adapted from it.
- Wikipedia: Excavata (CC BY-SA 4.0).
- Word definitions: the , each quoted from its Wikipedia article.
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