Anterior part of the embryonic digestive tract that develops into a mouth. The stomodeum includes as parts an invagination of the ectoderm and the stomodeal cavity. [ ]

This is just here as a test because I lose it

Term information

database cross reference

uberon_slim, pheno_slim, vertebrate_core, grouping_class

depicted by

editor note

consider indicating location. e.g. anterior. Note some AOs place this as part of oral opening, but it's not clear when this structure comes into existence

external definition

Anterior part of the embryonic alimentary canal formed as an invagination of the ectoderm; the future mouth.[TAO]
the primordial mouth region of the developing head, initially a midline ectodermal depression between the forebrain bulge (cranially) and the heart bulge (caudally) and between the maxillary and mandibular components of the first pharyngeal arch; the stomodeum is separated from the anterior end of the foregut by the buccopharyngeal membrane; the mouth is developed partly from the stomodeum, and partly from the floor of the anterior portion of the foregut; the lips, teeth, and gums are formed from the walls of the stomodeum, but the tongue is developed in the floor of the pharynx

has broad synonym

stomodeal-hypophyseal primordium

has exact synonym

mouth primordium
primitive oral cavity

has related synonym

mouth pit
oral pit
oral ectoderm



taxon notes

This class groups together disparate structures as all being the anterior part of the early metazoan digestive tract and precursor of the mouth. However, the developmental processes vary, so this class may be split in future. E.g. in mammals it is a rostral depression surrounded by prominences. Outgrowth of the prominences produces a stomodeal cavity.