Kaszab Zoltán (szerk.): A Magyar Természettudományi Múzeum évkönyve 77. (Budapest 1985)

Kordos-Szakály, M. ; Kordos, L.: Morphotypes of Hungarian fossil Celtis (Urticales) stones

Dimensional variations of morphotypes The measuring points of the stony endocarp of Celtis are shown on Fig. 1. Measurements were taken by a slide caliper to the moarest 0.1 mm. The distribution of certain data was considerably influenced by the presence or absence of the separation stump, the erosion of the outer surface or by the degree of an impurity adhered to it that was impossible to remove. On the specimens which are divided into two hemispheres only half width of the diagonal line along the equator could be measured, thus in those cases we obtained higher values (15-20% in excess) than in the cases of intact endocarps. The dimensions of the different morphotypes and the recent species are given in Tables 2-8, while distribution graphs calculated from the intact stony endocarps are shown in Fig. 4. The pill morphotype is the smallest and macro is the largest among the fossil forms investigated. It is conspicuous that a regular spheroid form can be found very rarely even within the sphere morphotype. Among the six morphotypes only in the pillow type could be observed an equatorial width greater than the height between the poles. All the other morphotypes are elongated. This phenomenon could also be observed among the investigated recent species. We could not find any absolute dimensional difference either among the fossil or among the recent stony endocarps. The distribution of every morphotype is tangential with that of some of its adjoining types. Unambigous dimensional differences are only between the smallest pill and largest macro, or the widest pillow and the narrowest torpedo-oval forms. Investigating the material of localities of different age, I could observe the following metrical characteristics within the six morphotypes separated according to the basic forms : "Pill" : an allometric dimensional difference of 7-8 % could be observed in the older samples (Rudabánya) in comparison with the younger ones (Tardosbánya, Polgárdi). A regular spheroid form is shown by only 5 specimens (20%), in three ones (12%) the equatorial width is greater than its height. "Sphere" : The 422 measurements from the 15 layers analyzed have a very even distribution per layer. The distributional diagrams of the different layers paries overlap themselves. While the average dimensions of the Pliocene and Lower Pleistocene stones are very close to each other, within the Middle Pleistocene series from Tarkő certain tendencies in dimensional changes can be observed. The stony endocarp becomes elongated and pointed (9%) from the older samples towards the younger ones but this trend is reversed the Tarkő 1 a sample which follows the previous ones with a considerable stratigraphical hiatus. In this case a more accurate metrical analysis demonstrates that in the older Tarkő layers the succession of Celtis was uninterrupted while in layer N° 1 this already could not be observed. In this case we have to consider the possibility of the appearance of another population in a different environment. The regular spheroid form is shown by 68 finds (15.3%) transitional forms towards the pillow form are shown by 86 specimens (19.4%). "Pillow" : The allometric dimensional increase of stony endocarp can be best observed in the pillow morphotype. From the smallest finds in Rudabánya and Polgárdi to the largest one found in the sample of Tarkő layer N° 1, there is an increase of approximately 37% as regards average values. Transition towards the sphere morphotype is demonstrated by a regular spherical form (20%) and an elongated form (8.2%). They are, however, close to the sphere form as regards their two characteristic dimensions, but not as regards their characteristic basic forms. "Torpedo" : Within this morphotype two marked dimensional categories can be distinguished. The Miocene and Pliocene specimens found at Rudabánya and Polgárdi are tangential only in 3 cases with the distribution of other finds of Upper Pliocene and Middle Pleistocene age. On the basis of the data available at present we cannot yet say whether the considerably smaller specimens (15%) might represent an independent morphotype or not. If these finds are the ancestral forms of the younger ones we must also think of a considerable dimensional increase. However, not a single sample's dimensional ratio is near to the regular spheroid form. "Oval" : Just as in the case of the torpedo morphotype, older finds of oval type are also considerably smaller (Rudabánya, Polgárdi, Csarnóta) than the younger specimens. Even among the latter we found another category of larger size, represented by two Osztramos specimens and by the Magyarkő find. There is an increase of 41 % between the average values of the smallest and the largest specimens, first there was a dimensional difference of 32% and later 9% between the different size categories. Like in the case of the torpedo samples, not a single sample's dimensional ratio is near to the regular sphere form. "Macro" : Despite having only a few measurable specimens of this type at hand, we can state with great probability that there was a dimensional increase of approximately 16-17% from the Lower Pannonian Rudabánya finds to the Lower Pleistocene Osztramos ones. Since the specimens