Validating marine Devonian biogeography: a study in bioregionalization

The Devonian record presents an opportunity to test and validate an existing marine bioregionalisation. This study is the first to use comparative biogeography and phylogenetic data to test Devonian bioregionalisation. Proposed in the 1960’s the Old World, Eastern Americas, and Malvinokaffric realms have been the functional standard within marine Devonian Biogeography. Data from 32 published phylogenies of Devonian marine taxa and a database of c.800 occurrences were analysed using phylogenetic software to test for area monophyly. The taxic occurrences within the current database were then tested against total fauna Devonian occurrences with the Palaeobiology Database to indicate differences in sampling. Results indicate that the current Devonian bioregionalisation is not representative of natural areas and requires revision. The result highlights areas that are most robust from which the study makes recommendations to improve the process and diagnosis of Devonian biogeographic areas. W...