A nuclear family, as opposed to extended family, is a kind of family with two parents and their children, it is typical in societies where people must be relatively mobile -- such as small hunter-gatherer societies and large industrial societies.
... ammonites, occur at Dui on the west coast, and Tertiary conglomerates, sandstones, marls and clays, folded by subsequent upheavals, in many parts of the island. The clays, ...