The female muscular organ of gestation in which the developing embryo or fetus is nourished until birth.
Comment:
[development-note] "Two uteruses usually form initially in a female fetus, and in placental mammals they may partially or completely fuse into a single uterus depending on the species. In many species with two uteruses, only one is functional. Humans and other higher primates such as chimpanzees, along with horses, usually have a single completely fused uterus, although in some individuals the uteruses may not have completely fused [Wikipedia:Uterus]"; [homology-note] "An infundibulum, uterine tube, uterus, and vagina also differentiate along the oviducts of eutherian mammals.[well established][VHOG]" xsd:string {date_retrieved="2012-09-17", external_class="VHOG:0001137", ontology="VHOG", source="ISBN:978-0030223693 Liem KF, Bemis WE, Walker WF, Grande L, Functional Anatomy of the Vertebrates: An Evolutionary Perspective (2001) p.678", source="http://bgee.unil.ch/"}; [taxon-note] "Most animals that lay eggs, such as birds and reptiles, have an oviduct instead of a uterus. In monotremes, mammals which lay eggs and include the platypus, either the term uterus or oviduct is used to describe the same organ, but the egg does not develop a placenta within the mother and thus does not receive further nourishment after formation and fertilization. Marsupials have two uteruses, each of which connect to a lateral vagina and which both use a third, middle 'vagina' which functions as the birth canal. Marsupial embryos form a choriovitelline 'placenta' (which can be thought of as something between a monotreme egg and a 'true' placenta), in which the egg's yolk sac supplies a large part of the embryo's nutrition but also attaches to the uterine wall and takes nutrients from the mother's bloodstream."