Kaszab Zoltán (szerk.): A Magyar Természettudományi Múzeum évkönyve 76. (Budapest 1984)
Kordos-Szakály, M.: New data to the Miocene flora of Nógrádszakál (Hungary)
The degree of relationship between the flora of the Paris valley and that of the other localities gave the following results in a decreasing order of magnitude: Bertece-valley 30.3%, Buják 22.2%, Mikófalva 20.9%, Bánhorváti 17.5%, Sály 14.1%, Balaton 13.1%, Eger-Tihamér 8.3%. At the same time the species which are present both in these localities and in the Paris valley form a fundamental flora which is characteristic for 7 localities compared with each other. These species, grouped according to their decreasing number, are the following : At 8 localities : Ulmus plurinervia At 7 localities : Parrotia pristina, Cercidiphyllum crenatum, Platanus aceroides, Zelkova ungeri At 6 localities : Ostrya atlantidis, Quercus pontica miocenica, Pterocarya denticulata, Salix angusta, Populus balsamoides At 5 localities : Ulmus longifolia, Populus populina At 4 localities : Ginkgo adiantoides, Ulmus biikkensis, Ostrya antiqua At 3 localities : Equisetum parlatorii, Cornus praemomum, Viburnum tinus, Fraxinus excelsior, Zelkova praelonga, Alnus crebrinervis, Quercus hispanica, Quercus pseudoalnus, Carya thomentosa At 2 localities: Callitrites brongniarti, Acer palaeotataricum, Hedera helix, Diospyros brahysepala, Ulmus drepanodonta, Salix fragilis, Populus termula The frequency values of common species in themselves do not give the actual chronological order of the 8 investigated localities containing 33 basic species. They refer only to the degree of relationship between the other floras and the flora found at the Paris stream. The chronological order corroborated by geological-stratigraphical data is the following: Eger-Tihamér —Bertece valley —Paris stream —Buják—Mikófalva—Bánhorváti—Sály—Balaton, where Eger-Tihamér is the oldest and Balaton is the youngest locality. On the basis of a poorer geological knowledge and lacking other similar investigations ANDREÁNSZKY (1959) was in a position to give an order which according to our present knowledge is erronous: EgerTihamér—Mikófalva—Bánhorváti—Buják—Balaton. With the estimation of C sp . value only the degree of relationship between the fossilized floras can be estimated and not their actual relationship. A useful method to determine this relationship is the Jaccard coefficient based also on common species: where K = Jaccard coefficient N x = number of taxa in the larger flora N 2 = number of taxa in the smaller flora C = number of common taxa I estimated the Jaccard coefficients for the flora-pairs following one another within the order of localities given above and obtained the following results : A coefficient of higher value indicates close relationship. From this comparison it is clear that the flora of Eger-Tihamér greatly differs from the others; the localities at the Bertece and Paris valleys are in relationship with each other to a moderate; to a certain degree the C K = N x +N 2 —C Eger-Tihamér — Bertece Bertece — Paris Paris — Buják Buják — Mikófalva Mikófalva •— Sály Sály — Bánhorváti Bánhorváti — Balaton 0.0175 0.1458 0.1016 0.1637 0.2244 0.1699 0.1491
