Crown Group

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 GroupContents of The Crown Group, Other Groups Under The Crown Group Concept, Palaeontological Significance of Stem- and Crown Groups, Stem-groups in Systematics

Other articles related to "crown group, groups, group, crown":

Crown Group - Stem-groups in Systematics
... As originally proposed by Karl-Ernst Lauterbach, stem-groups should be given the prefix "stem" (i.e ... Stem-Aves, Stem-Arthropoda), however the crown group should have no prefix ... The latter has not been universally accepted for known groups ...
Debate About Cambrian Lophotrochozoans - Suggested Phylogenies
... to the debate since 1990 Siphogonotuchida MOLLUSCA (crown group) "Siberian halkieriid" Canadia ANNELIDA (crown group) Wiwaxia Thambetolepis (halkieriid) Halkieria evangelista ... Kimberella Odontogriphus Wiwaxia Siphogonotuchida Orthrozanclus Halkieriids MOLLUSCA (crown group) Canadia ANNELIDA (crown group) Micrina ...
Odontogriphus - Phylogeny
... (Aplacophora) Polyplacophora Other crown group molluscs Cladogram Caron, Scheltema, et al ... Halsiphonids" (halkieriids + siphogonotuchids) MOLLUSCA (crown group) Wiwaxia Canadia ANNELIDA (crown group) Micrina BRACHIOPODA (crown group) Butterfield's ... the numbers of sclerites in its three concentric groups did not match at all ...
Fossils Of The Burgess Shale - Significance
... both diverse and widespread, suggesting that the group had a long, hidden history ... Charles Darwin regarded this sudden appearance of many animal groups with few or no antecedents as a major objection to his theory of evolution, and in 1859 ... — = Lines of descent = Basal node = Crown node = Total group = Crown group = Stem group Crown groups and stem group ...
Temnospondyls - Classification - Phylogeny
... In one of the earliest phylogenetic analyses of the group, Gardiner (1983) recognized five characteristics that made Temnospondyli a clade a bone at the back of the skull, the parasphenoid, is connected to another ... Depending on the classification of modern amphibians, they are either included in the crown group Tetrapoda or the stem of Tetrapoda ... Crown-group tetrapods are descendants of the most recent common ancestor of all living tetrapods and stem tetrapods are forms that are outside the crown group ...

Famous quotes containing the words group and/or crown:

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