OBO_REL:part_of (UNDECLARED) cleithrum Commonly, the cleithrum is a large, well-ossified bone provided with a dorsal and a ventral arm that form an angle of about 90 or a few more degrees. The dorsal arm may end in a sharp or spine-like process to articulate with the supracleithrum. At the confluence of both arms the bone presents a blade extending postero-ventrally and that may have different development among fishes. The anterior edge of the cleithrum is usually thick and may produce a medial plate of different degrees of development. Dermal bone that articulates dorsally with the supracleithrum and ventro-medially with the scapula and coracoid and mesocoracoid bone when the last bone is present. With the posttemporal and supracleithrum, the cleithrum supports the primary pectoral girdle. The cleithrum is located immediately behind the branchial cavity. TAO:0000184 cleithra cleithrum (French) clithra (French) clithrum (French) teleost_anatomy dermal bone pectoral girdle skeleton