Matskási István (szerk.): A Magyar Természettudományi Múzeum évkönyve 86. (Budapest 1994)

Barbacka, M.: Reconstructions of stomata in Komlopteris Barbacka and Pachypteris Brongniart and their adaptation to climate

1/4 or less. Thus, in general, the guard cells of the stomata in Pachypteris were better protected than in Komlopteris. This might be due to adaptation to conditions different from that of Komlopteris. The interpretation of adaptation of Pachypteris is not so evident as in the case of Komlopteris. The structure of stomata suggests a xeromorphic type, which is characteristic of halophytes as well, for instance P. papulosa HARRIS (HARRIS 1964). Undoubtedly the epidermis in P. papulosa is extremely well protected due to its thick cuticle and stomata furnished with papillae. However, considering that the territory of the Mecsek Mts. was of delta nature which occasionally might be flooded by salt water, Pachypteris banatica from this locality could possibly be a halophyte as well. The explanation of the connection between the type of the stomata (regular or irregular) and the character of adaptation to environmental circumstances (xerophytic or halophytic) demand further examinations, but we cannot exclude the possibility that genus both ecological forms occur within one. SUMMARY The reconstruction of stomata in Komlopteris and Pachypteris involved an attempt to solve the question about the connection between cuticular structure and climatic conditions. In the case of the locality in Mecsek the plant remains preserved in both morphology and cuticular structure. The observations were based on real climatic data, the adaptations seem to be visible not only in the construction of the stomata, but also in the morphology of the leaves. The leaves in question were large with large pinnae and entire margins in Komlopteris, while in Pachypteris they were far smaller and often with dissected margins. Earlier investigations into the plant-climate relationship suggested an influence of the climate on morphological and cuticular features (CHALONER & CREBER 1990). Although the examination concerned mainly angiosperms and a younger age (Late Cretaceous), the observations of Komlopteris and Pachypteris from Mecsek suggest that similar considerations may be related to older floras as well. Acknowledge m ents-I am very thankful to the Hungarian Geological Survey for providing me the opportunity to examine specimens of Pachypteris banatica from their collection. I would also like to express my thanks to Dr. JOHANNA H. A. VAN KONIJNENBURO-VAN CITTERT and to Dr. ZLATKO KVACEK for their advice during my work. References ANTEVS. E. (1914): Die Gattungen Thinnfeldia Ett. und Dicroidium Goth. - Kungl. Sv. Vet. Akad. Mandl. 51(6): 3-71. BARALE, G. (1971): Pachypteris desmomera (De Saporta) nov. comb., feuillage filicoide du Kimméridgien de Creys (Isère). - Bull. Soc. géol. de France (7) 13 (1-2): 174-180. BARALE, G. (1984): Les structures épidermiques de Pachypteris dagincourtii (Saporta) nov. comb., Ptéridospcrmale de L'Hettangien Inférieur de Saint-Arnand (Cher-France). - 109e Congrès national des Sociétés savantes, sciences. Dijon 2: 7-18. BARBACKA, M. (1994a): The new genus Komlopteris separated from Pachypteris Brongniart. - Rev. Paleobot. Palynol., in press. BARBACKA, M. (1994b): Pachypteris banatica from Liassic locality in Mecsek Mountains, Hungary. - Acta Paleobotanica 34 (1): in press. VAN DEN BURCH, J. & VAN CITTERT, J. H. A. (1984): A driffed flora from the Kimmeridgian (Upper Jurassic) of Lothberg Point, Sutherland, Scotland. - Rev. Paleobot. Palynol. 43: 359-396. CHALONER, W. G. & CREBER, G. T, (1990): Do fossil plants give a climatic signal? - Joum. Geot. Soc. 147: 343-350. DOLUDENKO, M. (1971): Thinnfeldia - mladshiy sinonim Pachypteris. [Thinnfeldia - junior synonym of Pachypteris.] -Paleont. J. 1971: 99-104.