In phylogenetics, the crown group of a collection of species consists of the living representatives of the collection together with their ancestors back to their last common ancestor as well as all of that ancestor's descendants. It is thus a clade, a group consisting of a species and all its descendents.
The name was given by Willi Hennig, the formulator of phylogenetic systematics, as a way of classifying living organisms relative to extinct ones. Though formulated in the 1970s, the term was not commonly used until its reintroduction in the 2000s by Graham Budd and Sören Jensen.
Read more about Crown Group: Contents of The Crown Group, Other Groups Under The Crown Group Concept, Palaeontological Significance of Stem- and Crown Groups, Stem-groups in Systematics
Famous quotes containing the words crown and/or group:
“It grazes the horizons, launched above
Mortality—ascending emerald-bright,
A fountain at salute, a crown in view—”
—Hart Crane (1899–1932)
“Laughing at someone else is an excellent way of learning how to laugh at oneself; and questioning what seem to be the absurd beliefs of another group is a good way of recognizing the potential absurdity of many of one’s own cherished beliefs.”
—Gore Vidal (b. 1925)