part of overlaps develops from leg joint prothoracic leg prothoracic coxa prothoracic trochanter prothoracic coxa-trochanter joint distal joint of prothoracic coxa FBbt:00007661 GTr The joint between the distal end of the prothoracic coxa and the proximal end of the trochanter. This joint is located dorsally, with the fossa (socket) of being part of the coxa and the condyle (ball) part of trochanter. fly_anatomy.ontology proximal joint of prothoracic trochanter T1 JTr coxa-trochanter joint presumptive prothoracic coxa-trochanter joint