A model of quantitative estimate of marine biogeographic provinciality - a case study of the permian marine biogeographic provincialism

The relationship between the number, position and orientation of lithospheric plates and marine biogeographic provinciality may be estimated quantitatively since the spatial distribution of organisms is primarily controlled by latitude-related temperature gradients and geographical barriers. This paper modifies Schopfs (1976) model for quantitatively estimating shallow marine provinciality in recognition of latitude-related temperature gradients as the primary biogeographical factor. A test of the modified model against modern marine zoogeography reveals high consistency between them. Using this modified model and the Permian palaeogeographical reconstruction maps of Scotese and McKerrow (1990) , fifteen shallow benthic marine provinces were estimated to be Early and Late Permian in age respectively. A comparison of the estimated Permian marine provinciality with previously recognised empirical provincial patterns reveals a high degree of congruity, which may imply that there existed moderate to high latitudinal thermal gradients during the Permian, a level probably similar to that of the present world.