Seriation of an original data matrix provides the paleoecologist with a simple and powerful tool for data manipulation. The data matrix lists the presences and absences of taxa in samples. The strategy is to generate a unidimensional sequence by rearranging the taxa and samples so that the presences are blocked along the matrix diagonal. The method is illustrated with two case studies from the Middle Devonian Hamilton Group of New York. The first represents a regressive interval and the seriation sequence summarizes the changes in fauna and samples which can be explained by falling sea level. The second example embraces a much wider range of variation. Seriation mainly recovers a first-order pattern related to depth and correlated variables. This seriation does not reveal parameters such as the nature of the substrate, turbidity, habitat stability and distance offshore. These data cannot be reduced to one dimension. In all cases, seriation yields results similar to those of cluster analysis and the first axis of multivariate ordinations frequently used by ecologists and paleoecologists. Seriation, paleoecology, Devonian, Hamilton Group, multivariate analysis.