Multivariate analysis of populations split by continental drift

A method of plotting data of more than two dimensions is used to analyze a paleobiogeographical problem relating to the lateral movement of continents. The method is suitable for the small samples common in paleontology; it seems to be effective in extracting more information of paleobiological and stratigraphical significance from the data than the usual graphical procedures of multivariate analysis. Brachycythere sapucariensis is a Lower Turonian (Cretaceous) species of ostracod found in the coastal sedimentary basins of Brazil (Sergipe), Gabon, and Nigeria. If the present positions of South America and Africa had been the same in the Cretaceous as today, one would expect the Nigerian and Gabonese individuals to be more alike than either of the African occurrences would be to the Brazilian ones. If, however, the drift interpretation of the origin of the South Atlantic Ocean is correct, Gabonese and Brazilian individuals should be more similar than either of these groups with Nigerian individuals. The results obtained do not disagree with the latter alternative.