ABSTRACT
Representatives of the Productida are a conspicuous component of Australasian Permian brachiopod faunas. They include genera that are endemic to a particular province or demonstrate a wider Gondwanan distribution. Several genera possess an apparent bipolar distribution. Few genera are shared between the Westralian and the Austrazean faunal provinces. Water temperatures and oceanic surface and intermediate depth current directions are considered to be the principal limiting factors for the migration of genera of the Productida. These factors may have been modified by Permian tectonic events such as the rotation of Pangaea and the separate contemporaneous movement of terranes within the Tethyan Sea. Westralian faunas exchanged genera with the warmer water faunas of the southern Tethyan margin (peripheral Gondwanan region) while Austrazean faunas developed in relative isolation under the influence of cooler and cold waters.
