The Mouse Adult Gross Anatomy Ontology and Mammalian Phenotype Ontology are downloaded weekly from the Mouse Genome Informatics databases at Jackson Laboratories (ftp://ftp.informatics.jax.org/pub/reports/index.html). For more information about these ontologies, see the MGI Publications Page at http://www.informatics.jax.org/mgihome/other/publications.shtml.
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
Comment:
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.