has part has part has_part characteristic of part of has modifier abnormal basioccipital bone morphology basioccipital bone dysplasia MPheno.ontology MP:0000079 any structural anomaly of the basilar process of the occipital bone in the base of the cranium, frequently forming a direct part of the occipital in the adult, but usually distinct in the young The basioccipital, exoccipital and supraoccipital bones are distinct bones in prenatal, neonatal and some early juvenile stages in most mammals. In adult organisms, these structures are fused to form the unified adult occipital bone. abnormal occipital bone morphology abnormal basicranium morphology morphology abnormal basioccipital bone