After the Cretaceous–Paleogene extinction event wiped out the non-avian dinosaurs (birds being the only surviving dinosaurs) and several mammalian groups, placental and marsupial mammals diversified into many new forms and ecological niches throughout the Paleogene and Neogene, by the end of which all modern orders had appeared.
A family of orientation refers to the family into which a person is born. A family of procreation describes one that is formed through marriage. These distinctions have cultural significance related to issues of lineage.
