A groove that is situated between the 1st and 2nd pharyngeal arch.
Comment:
[homology-note] "In all jawed vertebrates the first arch forms the jaw, while the second arch forms the hyoid apparatus. These two arches are separated by the first pharyngeal pouch and cleft.[well established][VHOG]" xsd:string {date_retrieved="2012-09-17", external_class="VHOG:0000969", ontology="VHOG", source="DOI:10.1016/j.semcdb.2010.01.022 Grevellec A, Tucker AS, The pharyngeal pouches and clefts: development, evolution, structure and derivatives. Seminars in Cell and Developmental Biology (2010)", source="http://bgee.unil.ch/"}