Obolidae, a family of Brachiopoda (q.v.), belonging to the order Inarticulata or Tretenterata (q.v.), which lived only in Palaeozoic times, where it ranged from the earliest to the Carboniferous ages. The family is allied to the living Lingula, but differs from the family of which that genus is the type, in the thickness of the margins of the shell-valves and the presence of a groove for the passage of the peduncle. The type-genus Obolus is Silurian.