part of mesoderm developing embryonic structure primordium caudal mesoderm 2025-01-16T14:23:32Z posterior mesoderm FBbt:00059338 Posterior-most region of the mesoderm. At the blastoderm stage, it comprises about 40 cells (Sun et al., 2023). It gives rise to the founder cells of the longitudinal midgut muscles (Ismat et al., 2010) and the stellate cells of the Malpighian tubules (Denholm et al., 2003). fly_anatomy.ontology