Matskási István (szerk.): A Magyar Természettudományi Múzeum évkönyve 79. (Budapest 1987)
Kecskeméti, T.: Contributions to the phylogenetic connections of Nummulites species
in parallel lines (BLONDEAU 1972). In the present scheme, that of BLONDEAU is followed, since of the two taxa, it is the somewhat more tightly coiled A', distons that is supposed to have been a direct-line predecessor of TV. millecaput "petit", a Lower Lutetian form also provided with a tightly coiled spire. N. millecaput "petit" occupies an intermediate position between N. distans and A 7 , millecaput both taxonomically (shell size, thightness of spire and its cyclicity, thickness of marginal cord) and stratigraphically. For this reason, the lineage is regarded as a typical Lower Lutetian taxon. Generalizing this approach is supported by the marked geographic range of the taxon, too. Typical N. millecaput of Upper Lutetian age is a direct descendant of N. millecaput "petit". The continued development of the morphological characters listed in the foregoing can be readily observed in it. Especially the tightness of the spire and its cyclicity show progressive features, a considerable increase in the size of test and the concomitant increase in the number of chambers as well as the doubled revolutions and the appearance of adventive chambers are features indicative of further specialization of shell structure. During the Late Lutetian the evolution of the species was speeded up. Some diagnostic features underwent a rapid and marked differentiation which resulted in the disintegration of N. maximtts and N. dufrenoyi. All three species underwent a pronounced specialization with the passing of time, their evolution gradually reached completion and, developing on parallel lines, they soon reached the culmination of their development. After a short acme, upon adverse changes in environment and probably also because of a reduction in their evolutionary vitality, they got to the paracme stage, where confronted with difficulties due to overspecialization (gigantism, problems of feeding and consolidating the test, etc.) they underwent a rapid decline, to get extinct in final Late Lutetian time. The source of the Lower Ilerdian N. solitarius was the N. burdigalensis —perforatus group. An intermediary taxon between N. solitarius and Lower Cuisian N. burdigalensis is represented by the Ilerdian N. pemotus. N. burdigalensis exhibits a marked evolutionary plasticity, thus representing an important nodal point in phylogeny. A total of at least 4 taxa evolved from it. Its directline follow-up is represented in the Upper Cuisian by N. aff. gallensis, a taxon related to N. gallensis. Collateral development led to the birth of N. campesinus, a form of marked granulation and comparatively loosely coiled spire, to that of finely granulate and tightly-spired N. friulanus and to N. aff. burdigalensis, form found at Devecser that is much more highly specialized than N. burdigalensis (as shown by the most important feature — a spire becoming cyclic). All three taxa had differentiated into independent species by Late Cuisian time, N. aft', burdigalensis having been the last to achieve this (KECSKEMÉTI 1973). It was through the direct-line development of N. aff. gallensis (= N. burdigalensis ssp. b; comp. SCHAUB 1951, p. 121) that the two main branches of the group, transient through the Lutetian, evolved. One of the two progressed via N. gallensis, N. uranensis, N.praeaturicus and N. aturicus, forms characterized by an increasingly more differentiated spire, to reach the large end-form. N.perforatus, an Upper Lutetian species having a typical 3-stage spire. This, so-called aturicus line is joined by A 7 , baconicus which, fits, with its spire, between N. uranensis and N. praeaturicus. The species of the aturicus line are well-studied. Their genetic connections can be traced very well so that the line in question has become the best-documented stage in the phylogeny of the Nummulites (SCHAUB 1962, 1963). The species of this line occur all in this country too. Therefore the goal the present writer has had to achieve has been rather restricted to identify the position of the corresponding taxa along the lineage. The second main line, that of meneghinii, leads through N. lehneri and N. meneghinii, to the Upper Lutetian end-member, N. biedai. a form of similarly great size. The determina-
