develops from embryonic precursor cell of adult muscle adult muscle precursor cell adult myoblast P1 AdMus FBbt:00003232 fly_anatomy.ontology Cell persisting from the embryonic stage that contributes to the adult musculature. During metamorphosis, myoblasts aggregate and fuse together to form the adult muscle either on the remnants of larval muscles or independently on the newly forming adult epidermis (Bate, 1993). AMP myoblast embryonic primordium of adult muscle precursor trunk mesoderm derivative