Crown group

Crown Group is a term used in phylogenetic systematics ( cladistics ) and refers to a clade at the base of the last common ancestor of all extant taxa of this clade is. In addition to said recent taxa include only those fossil representatives of the crown group, which also go back to the last common ancestor.

Home group

As a regular line or trunk group is called the group paraphyletic ancestors of a crown group composed of all fossil forms that are more closely related to the crown group than with any other extant group, but do not belong to the crown group itself. To include for example the " non-avian dinosaurs " (non - avian dinosaurs ), the pterosaurs and the Silesauriden to the root group of the birds, and the birds with them have a common ancestor that is more recent than the last common ancestor with its closest living relatives the crocodiles.

Pan Group

Crown group and stem group together in turn form a monophyletic group Pan (English also total group). Thus, the extant mammals are the synapsids crown group, the non- mammalen therapsids, together with the " Pelycosauria " the mammalian core group and the Synapsida as such the Pan Group.

Swell

• Philip CJ Donoghue: Saving the stem group - a contradiction in terms? Paleobiology 31 (4 ), 2005, pp. 553-558.
• B. Wiesemüller, H. Rothe, W. Henke: Phylogenetic systematics. Springer, 2003, ISBN 3-540-43643- X.

• Taxonomy