Matskási István (szerk.): A Magyar Természettudományi Múzeum évkönyve 79. (Budapest 1987)
Kecskeméti, T.: Contributions to the phylogenetic connections of Nummulites species
ANNALES HTSTORICO-NATURALES MUSEI NATIONALTS HUNGARICI Tomus 79. Budapest, 1987 p. 61-75. Contributions to the phylogenetic connections of Nummulites species by T. KECSKEMÉTI, Budapest T. KECSKEMÉTI : Contributions to the phylogenetic connections of Nummulites species. — Annls hist.-nat. Mus. natn. hung. 1987 79: 61-75. Abstract — This sketch has been made on the basis of similarity in morphological features and ontogeny of 109 taxa with special regards to their stratigraphical and geographical distribution. The compilation had three main aims: incorporation of the Hungarian Nummulites species into the general phylogenetic scheme of the nummulitids; fitting some missing links into certain evolutionary lineages; correction of some details of former phylogenetic schemes. —• Eight phylogenetic groups have been distinguished: laevigatus-brongniarti (N. penzesgyoerensis ), distansirregularis, burdigalensis-perforatus (N. baconicus ), globulus-variolarius (N. suemegensis, N. dudarensis, N. rozlozsniki), discorbinus (N. majzoni, N. iohannis, N. zircensis), partschi —lorioli —fabianii (N. böckhi, N. gizehensis laszloi, N. gizehensis tatabanyaënsis ), striatus (N. subplanulatus, N. kovacsiensis, N. subtilis inaior, N. kopeki, N. striatus pannonicus, N. striatus inflatus ) and an anomalus — stellatus ÍN. anomaloides ) group. In brackets: the taxa which occurred only in Hungary so far. With 1 Table. During the monographic synthesis of the Nummulites fauna of the Bakony Mountains (KECSKEMÉTI 1983) many new data, a considerable part of them onto- and phylogenetic results, were collected. They not only enabled the author to outline the phylogeny of these forms, but they were likely to show a compelling need for such work. This phylogenetic sketch is based on the similarity of the morphological features of single species and on their ontogeny. In addition, the stratigraphie and paleogeographic ranges of the taxa involved have been taken into consideration. Most of the morphological characters considered are internal ones. Of these, in a hierarchical order, the growth trend of the spire, the shape and number of chambers and septa, the characters of the embryonic stage in the microspheric generation and the size and shape of the protoconch in the megalospheric one are most important. Of the external features, the behaviour of the septal lines and the presence or absence of granulation are diagnostic The variation of the morphological features has been considered mainly for the microspheric generation, since the characters of this generation, primarily its spiral pattern, are the best reflection of the main evolutionary trends. On the basis of perfection-bound changes in these characters, the taxa were placed in morphological lineages. Since these changes are traceable in time, they can be regarded as being of phylogenetic value. The general trend of evolution of the Nummulites species can be traced best in the ontogeny of the microspheric generation. In studying it, the writer could rely on statements scattered in the relevant literature (HARPE 1881-1883, HEIM 1908, BOUSSAC 1911, DOUVIXLÉ 1919, ROZLOZSNIIC 1927, ABRARD 1928, ScHAUB 1951, 1963, 1966a, b; HOTTINGER 1977, GOLEV 1978). Of the above-mentioned references, the following three, supported by sound evidence as they are, have been chosen as most reliable starting points for the present work. — The spire of the microspheric generation consists of 3 stages: internal, embryonic (corresponding to the protoconch diameter of the megalospheric generation), middle (corresponding to the full shell diameter of an adult megalospheric form) and external stage representing the stretch of spire above the diameter of test of the megalospheric generation) (HEIM 1908). Thus in his comparative studies the writer could compare the spire of the megalospheric form with the middle stage of the microspheric one, whereas it is in the last, or possibly the penultimate, whorl of the megalospheric forms that the trend characteristic of the external stage of growth of the microspheric form is observed, being comparable. — The variation in chamber shape is of particular importance for ontogeny. Moreover, as pointed out by ROZLOZSNIK (1927), it is important both onto- and phylogenetically, an operculinoid (high) or assilinoid (isometric) shape of chamber is typical of the primitive taxa and a nummulitoid (long) one is characteristic of the highly developed ones.
