The proximal portion of the digestive tract, containing the oral cavity and bounded by the oral opening. In vertebrates, this extends to the pharynx and includes gums, lips, tongue and parts of the palate. Typically also includes the teeth, except where these occur elsewhere (e.g. pharyngeal jaws) or protrude from the mouth (tusks).
Comment:
[development-note] "some AOs place this as developing from the stomodeum but we weaken this to developmental contribution, as the mouth includes non-ectodermal derivatives"; [homology-note] "Molecular and developmental cell lineage data suggest that the acoel mouth opening is homologous to the mouth of protostomes and deuterostomes and that the last common ancestor of the Bilateria (the 'urbilaterian') had only this single digestive opening.[well established][VHOG]" xsd:string {date_retrieved="2012-09-17", external_class="VHOG:0000812", ontology="VHOG", source="DOI:10.1038/nature07309 Hejnol A, Martindale MQ, Acoel development indicates the independent evolution of the bilaterian mouth and anus. Nature (2008)", source="http://bgee.unil.ch/"}