Rodzaj Cercidiphyllum z Turowa

Abstract

GENUS CERCIDIPHYLLUM AT TURÓW

Summary

In two siderite concretions, two leaf imprints have been encountered in a brown coal deposit at   Turów I (200 m a.s.l., section 20-21), one of them with a counter part. Both imprints belong to the species Cercidiphyllum crenatum (U n g.) B r o w n.

The leaves of this type have previously been determined as Populus, Grewia, Zizyphus, Cercis, Grewiopsis, Trochodendroides, etc. R. Brown, a palaeobotanist from the USA has determined, on the basis of detailed morphological research, that they are most similar to a relict species Cercidiphyllum japonicum S i e b. et  Z u c c. that lives in Japan and China, and is to-day the only representative of the family Cercidiphyllaceae. He has also described five species of Cercidiphyllum: C. ellipticum (N e w b e r r y) B r o w n - in Cretaceous and Palaeocene; C. arcticum (H e e r) B row n - in Palaeocene and Eocene; C. elongatum  B r o w n - in Eocene and Oligocene; C. crenatum (U n g.) B r o w n – in Oligocene and Miocene; and C. japonicum S i e b. et  Z u c c. - in the Upper Miocene or Pliocene and till the present time.
The table attached to the Polish text presents data on the, occurrence of the genus Cercidiphyllum in Poland and in the adjacent areas. It may be seen (Table 1) that in these areas the genus Cercidiphyllum reached the maximum of the development at the Miocene time. C. crenatum (U n g.) B r o w n was here a predominant species, although the problem whether it was the sole representative of the genus is disputable.