| Namespace | MPheno.ontology | Obsolete | false |
| description | any structural anomaly of the fourth endodermal branchial pouch located between the fourth and sixth branchial arches (a fifth arch never establishes itself in amniotes); in most mammals, excluding rodents, the dorsal part of each fourth pouch develops into a superior parathyroid gland (parathyroid IV), which lies on the dorsal surface of the thyroid gland (the parathyroid glands derived from the third pouches descend with the thymus and are carried to a more inferior position than the parathyroid glands that are derived from the fourth pouches); the elongated ventral part of each fourth pouch develops into the ultimopharyngeal body, which fuses with the thyroid gland, giving rise to the calcitonin-producing parafollicular or C-cells of the thyroid gland |
