The allosaurid family used to be larger, containing numerous medium- to large-sized Jurassic theropods, but the precise number of species is highly debatable and periodically in flux. Now, most species have either been synonymized with others, declared dubious or invalid, or reclassified as being members of other families in the superfamily Allosauroidea (being Metriacanthosauridae, Neovenatoridae, and Carcharodontosauridae), or more primitive members of the Megalosauroidea. Allosaurus itself is now the only universally accepted member, though the exact list of its species is just as debatable.