Anamnia
The division of living beings into systematics is a continuous subject of research. Different systematic classifications exist side by side and one after the other. The taxon treated here has become obsolete due to new research or is not part of the group systematics presented in the German-language Wikipedia.
As anamniotes (Greek. Toggle "not" and amnion "Embryonalhülle"), even Anamniota or Anamnier are vertebrates referred whose embryos not of embryonic membranes (serosa and amnion are surrounded). In contrast, vertebrates with embryonic envelopes are called amniotes .
The group includes the amphibians and the paraphyletic group of fish - according to modern taxonomy, the amphibians, bony fish , cartilaginous fish , lampreys and hagfish as well as various extinct groups of vertebrates. Unlike many amniotes, the anamnia is always bound to water, at least in the early stages of individual development, and often to a moist environment even after reaching sexual maturity, while the embryo and fetus of the amniota provide the moist environment in the amniotic egg or uterus, which is necessary for their development of the mother.
In contrast to the amniotes, the anamnia are a classic example of a paraphyletic taxon , which is characterized by original features: their last common ancestor is the last common ancestor of all vertebrates.
supporting documents
- ^ A b c d Keyword “Anamnia” in: Herder-Lexikon der Biologie. Spectrum Akademischer Verlag GmbH, Heidelberg 2003. ISBN 3-8274-0354-5 .
- ↑ a b Keyword "Amniota" in: Herder-Lexikon der Biologie. Spectrum Akademischer Verlag GmbH, Heidelberg 2003. ISBN 3-8274-0354-5 .