BIOGEOGRAPHIC ASSOCIATIONS OF DEVONIAN BRYOZOA IN LAURUSSIA, GONDWANA, SIBERIA, KAZAKHSTANIA, AND CHINA

The Devonian was a period of significant geographic change coinciding with some of the most extensive reef development in Earth’s history. A variety of marine organisms, including brachiopods, trilobites, corals, and bryozoans, have been employed in multiple studies of Devonian biogeography and patterns of endemism, origination, and extinction. 52 local areas of sufficient generic diversity have been analyzed using the Kulczynski index of overall faunal similarity, Parsimony Analysis of Endemicity (P. A. E.), seriation, and Principal Coordinates Analysis. Local areas are defined temporally, lithologically, and spatially, and include regions of Gondwana, Laurussia, Siberia/Mongolia, and Kazakhstania. Local areas were selected based upon the proportion of genera of sufficient endemic character present in each area. Through cluster analysis and P. A. E., three major associations (Laurussia I, Laurussia II, and Old World), referred to as realms, and six minor associations (Mongolia, Eurasia I, Eurasia II, Afro-Eurasia, Appohimchi I, and Appohimchi II), referred to as provinces, are distinguished. The geographic distribution of provinces indicates a lack of latitudinal control of generic distribution. Additionally, results lend support for a major extinction event among Bryozoa occurring at the end of the Givetian, which appears to have impacted North American provinces the most adversely.