C1 and C2 are crown groups of extant species within the clade T – the total group or pan-group – which also contains the stem group S1 of extinct species. The crown group C1 and the stem group S1 form the total group T1. T1 and C2 are sisters.
Part of a series on
Evolutionary biology
Darwin's finches by John Gould
Index
Introduction
Main
Outline
Glossary
Evidence
History
Processes and outcomes
Population genetics
Variation
Diversity
Mutation
Natural selection
Adaptation
Polymorphism
Genetic drift
Gene flow
Speciation
Adaptive radiation
Co-operation
Coevolution
Coextinction
Divergence
Convergence
Parallel evolution
Extinction
Natural history
Origin of life
Common descent
History of life
Timeline of evolution
Human evolution
Phylogeny
Biodiversity
Biogeography
Classification
Evolutionary taxonomy
Cladistics
Transitional fossil
Extinction event
History of evolutionary theory
Overview
Renaissance
Before Darwin
Darwin
Origin of Species
Before synthesis
Modern synthesis
Molecular evolution
Evo-devo
Current research
History of speciation
History of paleontology (timeline)
Fields and applications
Applications of evolution
Biosocial criminology
Ecological genetics
Evolutionary aesthetics
Evolutionary anthropology
Evolutionary computation
Evolutionary ecology
Evolutionary economics
Evolutionary epistemology
Evolutionary ethics
Evolutionary game theory
Evolutionary linguistics
Evolutionary medicine
Evolutionary neuroscience
Evolutionary physiology
Evolutionary psychology
Experimental evolution
Phylogenetics
Paleontology
Selective breeding
Speciation experiments
Sociobiology
Island biogeography
Systematics
Universal Darwinism
Social implications
Evolution as fact and theory
Social effects
Creation–evolution controversy
Theistic evolution
Objections to evolution
Level of support
Evolutionary biology portal
Category
v
t
e
In phylogenetics, the crown group or crown assemblage is a collection of species composed of the living representatives of the collection, the most recent common ancestor of the collection, and all descendants of the most recent common ancestor. It is thus a way of defining a clade, a group consisting of a species and all its extant or extinct descendants. For example, Neornithes (birds) can be defined as a crown group, which includes the most recent common ancestor of all modern birds, and all of its extant or extinct descendants.
The concept was developed by Willi Hennig, the formulator of phylogenetic systematics, as a way of classifying living organisms relative to their extinct relatives in his "Die Stammesgeschichte der Insekten",[1]
and the "crown" and "stem" group terminology was coined by R. P. S. Jefferies in 1979.[2] Though formulated in the 1970s, the term was not commonly used until its reintroduction in 2000 by Graham Budd and Sören Jensen.[3]
^Hennig, W. (1969). Die Stammesgeschichte der Insekten (in German). Frankfurt am Main: Waldemar Kramer. ASIN B0000EGSML. OCLC 1612960.
^Jefferies, R.P.S. (1979). "The Origin of Chordates — A Methodological Essay". In House, M.R. (ed.). The Origin of Major Invertebrate Groups. London; New York: Academic Press for The Systematics Association. pp. 443–447. ISBN 0123574501. OCLC 767789225.
^Budd, G.E.; Jensen, S. (2000). "A critical reappraisal of the fossil record of the bilaterian phyla". Biological Reviews. 75 (2): 253–295. doi:10.1111/j.1469-185X.1999.tb00046.x. PMID 10881389. S2CID 39772232.
In phylogenetics, the crowngroup or crown assemblage is a collection of species composed of the living representatives of the collection, the most recent...
The Crown Publishing Group is a subsidiary of Penguin Random House that publishes across several fiction and non-fiction categories. Originally founded...
CrownGroup Holdings is a property group that deals with the development and investment of properties in Australia. It was co-founded in 1996 by Paul Sathio...
facilities. The Group includes: Crown World Mobility, Crown Relocations, Crown Records Management, Crown Fine Art, Crown Logistics, Crown Wine Cellars and...
crowngroup. They would instead lie along the stem group, a subset of animals related to, but not within, the crowngroup. The stem and crowngroup together...
skeletons". Some writers restrict the term "mammal" to the crowngroup mammals, the group consisting of the most recent common ancestor of the monotremes...
("mammalian forms") is a clade that contains the crowngroup mammals and their closest extinct relatives; the group radiated from earlier probainognathian cynodonts...
The Toyota Crown (Japanese: トヨタ・クラウン, Hepburn: Toyota Kuraun) is an automobile which has been produced by Toyota in Japan since 1955. It is primarily...
Crown broadly represents the state in all its aspects within the jurisprudence of the Commonwealth realms and their subdivisions (such as the Crown Dependencies...
one of the three living amphibian groups alongside Anura (frogs) and Urodela (salamanders). Gymnophiona is a crowngroup, encompassing all modern caecilians...
restricted to the crowngroup, with the Caudata being used for the total group.[citation needed] Others restrict the name Caudata to the crowngroup and use Urodela...
common ancestor of the crowngroup; it is a relative concept, for example tardigrades are living animals that form a crowngroup in their own right, but...
Gauthier defined Aves to include only the crowngroup of the set of modern birds. This was done by excluding most groups known only from fossils, and assigning...
Archosauria nowadays roughly corresponds to Archosauriformes, a group named to encompass crown-group archosaurs and their close relatives. The oldest true archosaur...
definition for alligators, and is more inclusive than the crowngroup Alligatoridae. As a crowngroup, Alligatoridae only includes the last common ancestor...
started with symbiogenesis. In turn, the LECA gave rise to the eukaryotes' crowngroup, containing the ancestors of animals, fungi, plants, and a diverse range...
It is the earliest known animal predator. Auroralumina is the oldest crown-group cnidarian. The fossil, whose name recalls the Latin for "dawn lantern"...
group called Parareptilia. Parareptilia means "at the side of reptiles" and was placed outside the clade Reptilia, which was considered a crowngroup...
been used in deducing key genes for barcoding of diverse group of species. Clade Crowngroup Glossary of scientific naming Monotypic taxon Paraphyly Polyphyly...
living crown-group (respectively the Monotremata, Marsupialia and Placentalia) plus any fossil species which are more closely related to that crown-group than...
be the earliest crowngroup squamates based on morphological data, but genetic data suggest that geckos are the earliest crowngroup squamates. Iguanians...
studies, as they might branch before the mandibulate crown-group. Within the pancrustacean crown-group, only Malacostraca, Branchiopoda and Pentastomida...
Crown Resorts Limited is an Australian gaming and entertainment group that owns and operates various entertainment complexes, including Crown Melbourne...
Crown Estate in England, Wales, and Northern Ireland is managed by the Crown Estate Commissioners. In Scotland, the Crown Estate is managed by Crown Estate...
mammals and reptiles, and all its descendants". As Gauthier makes use of a crowngroup definition, Amniota has a slightly different content than the biological...
Cambrian. They were likely major predators of the Cambrian period. However, crown-group priapulids cannot be recognized until the Carboniferous. 22 extant species...
ray-finned fish. About 96% of all living fish species today are teleosts, a crowngroup of ray-finned fish that can protrude their jaws. The tetrapods, a mostly...
Global Information
