Age-range classes defined by the Age Ontology. Age-range classes were generally defined based on the MeSH age range definitions, with minor changes introduced to improve consistency. In the Age Ontology, age-range classes that are contained within another age-range class are defined as subclasses of that class. Each age-range class is made disjoint from all other age-range classes since each specific age can belong to only one age range class. * This age range was modified from the MeSH definition.