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The prokaryote group is another example; it is paraphyletic because it is composed of two Domains (Eubacteria and Archaea) and excludes (the eukaryotes). It is very useful because it has a clearly defined and significant distinction (absence of a cell nucleus, a plesiomorphy) from its excluded descendants. [citation needed]
In taxonomy, a group is paraphyletic if it consists of the group's last common ancestor and all descendants of that ancestor excluding one or more subgroups. See also the categories Polyphyletic groups and Obsolete taxa
A stem group is a paraphyletic assemblage composed of the members of a pan-group or total group, above, minus the crown group itself (and therefore minus all living members of the pan-group). This leaves primitive relatives of the crown groups , back along the phylogenetic line to (but not including) the last common ancestor of the crown group ...
Systematists today do not treat Protista as a formal taxon, but the term "protist" is still commonly used for convenience in two ways. [22] The most popular contemporary definition is a phylogenetic one, that identifies a paraphyletic group: [23] a protist is any eukaryote that is not an animal, (land) plant, or (true) fungus; this definition [24] excludes many unicellular groups, like the ...
In bacteriology, the renaming of species or groups that turn out to be evolutionary grades is kept to a minimum to avoid misunderstanding, which in the case of pathogens could have fatal consequences. When referring to a group of organisms, the term "grade" is usually enclosed in quotation marks to denote its status as a paraphyletic term.
Though bryophytes were considered a paraphyletic group in recent years, almost all of the most recent phylogenetic evidence supports the monophyly of this group, as originally classified by Wilhelm Schimper in 1879. [8] The term bryophyte comes from Ancient Greek βρύον (brúon) 'tree moss, liverwort' and φυτόν (phutón) 'plant'.
Excavata is an extensive and diverse but paraphyletic group of unicellular Eukaryota. [1] [2] The group was first suggested by Simpson and Patterson in 1999 [3] [4] and the name latinized and assigned a rank by Thomas Cavalier-Smith in 2002.
Basal eudicot is an informal name for a paraphyletic group. The core eudicots are a monophyletic group. [ 11 ] A 2010 study suggested the core eudicots can be divided into two clades, Gunnerales and a clade called Pentapetalae , comprising all the remaining core eudicots.