parasegment parasegment 15 FBbt:00000153 Embryonic metameric unit comprising the posterior compartment of abdominal segment 9 and the anterior compartment of abdominal segment 10. Definition added based on definitions for other parasegment definitions. Parasegment 14 is the most posterior parasegment mentioned in the original parasegment paper (Martinez-Arias and Lawrence, 1985), but subsequent papers (e.g.- Celniker et al., 1989, Mlodzik et al., 1990) refer to parasegment 15, and Campos-Ortega and Hartenstein (1997), refer to two parasegments posterior to parasegment 14 defined by homeotic gene expression. fly_anatomy.ontology