has part has part bone element pneumatized bone A bone that is hollow or contains many air cells, such as the mastoid process of the temporal bone[TMD]. Wikipedia:Skeletal_pneumaticity Skeletal pneumaticity is the presence of air spaces within bones. Skeletal pneumaticity exists only in synapsids and archosaurs. It is generally produced during development by excavation of bone by pneumatic diverticula (air sacs) from an air-filled space such as the lungs or nasal cavity. Pneumatization is highly variable between individuals, and bones not normally pneumatized can become pneumatized in pathological development. Pneumatization occurs in the skulls of mammals, crocodilians and birds among extant groups, as well as extinct archosaurs including the dinosaurs and pterosaurs. Pneumatic spaces include the paranasal sinuses and some of the mastoid cells[WP]. [Wikipedia:Skeletal_pneumaticity] SCTID:333008005 UBERON:0008193 os pneumaticum FMA:7478 hollow bone subclasses of this should be checked for taxonomic consistency pneumatic bone galen:PneumaticBone uberon pneumatic cavity of bone