In this contribution to "Palaeozoic Ostracod Classification", the history o
f the podocopine Superfamily Bairdiacea SARS, 1888 is reviewed, and (in par
ticular) the systematics and the stratigraphical, ecological and zoogeograp
hical significance of the world-wide, Middle Ordovician to Recent Family Ba
irdiidae SARS, 1888 are discussed (however, Palaeozoic members only are dea
lt with in detail).