bilaterian http://id.loc.gov/authorities/subjects/sh2011005559 http://purl.obolibrary.org/obo/NCBITaxon_33213 https://en.wikipedia.org/wiki/Bilateria https://en.wikipedia.org/wiki/Category:Bilaterians https://eol.org/pages/3014411 https://species.wikimedia.org/wiki/Bilateria https://www.wikidata.org/wiki/Q5173 Animals with bilateral symmetry, i.e., they have a head (anterior) and a tail (posterior) as well as a back (dorsal) and a belly (ventral); therefore they also have a left side and a right side. Bilateria bilaterians eumetazoan