part of part of preceded_by preceded by embryo stage part embryo stage neurula stage organogenesis stage A stage at which the ectoderm, endoderm, and mesoderm develop into the internal organs of the organism. BILS:0000111 BilaDO:0000010 HsapDv:0000015 MmusDv:0000018 OGES:000005 OGES:000032 UBERON:0000111 segmentation stage uberon