The respiratory muscles that arise from the lower border of one rib and insert into the upper border of the adjoining rib.
Comment:
[homology-note] "Inspiration by active expansion of the thorax evolved later, in the ancestor of reptiles, birds, and mammals. This was powered originally by the intercostal muscles (as in lizards or crocodilians) and later (in mammals only) by a muscular diaphragm.[well established][VHOG]" xsd:string {date_retrieved="2012-09-17", external_class="VHOG:0000903", ontology="VHOG", source="ISBN:978-0262112789 Kent RD, The MIT Encyclopedia of Communication Disorders (20039 p.56", source="http://bgee.unil.ch/"}