organ of metabolic interchange between fetus and mother, partly of embryonic origin and partly of maternal origin[GO]. The fetal portion of the placenta is known as the villous chorion. The maternal portion is known as the decidua basalis. The two portions are held together by anchoring villi that are anchored to the decidua basalis by the cytotrophoblastic shell. [ ]

Synonyms: eutherian placenta allantoic placenta

This is just here as a test because I lose it

Term information

database cross reference

uberon_slim, efo_slim, pheno_slim, organ_slim


Marsupials possess only a rudimentary yolk-type placenta, with reduced nutrient and oxygen exchanging capabilities.

depicted by

homology notes

Phylogenetic analyses of the concatenated data set using maximum parsimony, maximum likelihood and distance based (neighbour joining) methods all converged on a nearly identical, well supported topology defining four principal eutherian lineages. The results affirm monophyly of traditional placental orders (except Artiodactyla and Insectivora), and also support some previously proposed, as well as new, superordinal clades.[well established][VHOG]



taxon notes

Eutherians: In eutherians, the chorioallantoic membrane of the fetus establishes intimate contact with the adjacent vascular wall of the mother's uterus to produce the placenta, a composite structure formed in part from tissues of the fetus and in part from tissues of the mother [ISBN:0073040584 (Vertebrates, Kardong)]. TODO - is taxon restriction too strict, even if we restrict def to allantoic placenta? - WP says: also found in some snakes and lizards with varying levels of development up to mammalian levels. Pough et al. 1992. Herpetology: Third Edition. Pearson Prentice Hall:Pearson Education, Inc., 2002. // See also: DOI:10.1002/jmor.11011