mesothoracic pleurosternal muscle mesothoracic pleurosternal muscle 60 2022-07-05T13:30:44Z FBbt:00058916 fly_anatomy.ontology pleurosternal 2 Small mesothoracic pleurosternal muscle. It attaches ventrally and medially on the mesofurca and dorsolaterally on the thoracic joint of the prealar apophysis. It is located ventrally to the pleurosternal muscle 59. ps2 muscle