Belemnites of the Neobelemnella kazimiroviensis group – a comparison of the self-organizing Kohonen networks algorithm with the classic palaeopopulation statistical approach and approaching their origin
Belemnites of the Neobelemnella kazimiroviensis group were classified applying the Artificial Neural Networks method, the self-organizing Kohonen algorithm. Four species are distinguished, Neobelemnella kazimiroviensis (Skołozdrówna, 1932), Neobelemnella pensaensis (Naidin, 1952), Neobelemnella skolozdrownae (Kongiel, 1962), and Neobelemnella aff. kazimiroviensis (Skołozdrówna, 1932). The first two species occur in the Upper Maastrichtian of Central Asia (Kazakhstan, Turkmenistan), Russia, Poland, Denmark, the Netherlands and Belgium. N. skolozdrownae is limited to Poland, Denmark, the Netherlands and Belgium, while N. aff. kazimiroviensis occurs in the Volga Basin (Russia) and Kazakhstan. The evolution of the N. kazimiroviensis group from a member of the Belemnella praearkhangelskii group of Central Russia or Kazakhstan or from the Belemnitella americana group from New Jersey (USA) is discussed applying Hierarchical Cluster Analysis and Multidimensional Comparative Analysis. A member of the Bt. americana group – ? Neo-belemnella subfusiformis (Whitfield, 1892) – is referred to the genus Neobelemnella Naidin, 1975 albeit with a query. This supports the hypothesis that the N. kazimiroviensis group could have evolved from a North American precursor.