Tropy gadów w dolnym liasie Świętokrzyskim

Abstract

TRACKS OF REPTILIA IN THE LOWER LIASSIC OF THE ŚWIĘTOKRZYSKIE MOUNTAINS MIDDLE POLAND

Summary

In the Lower Liassic deposits found to occur in the Śwęitokrzyskie Mountains, tracks of reptilia have for the first time been encountered in sandstones. So far, the presence of two varieties have been noted: a pentadactyle (Table I, Fig. 1; Table II, Fig. 2), and a tri- or tetradactyle (Table III, Fig. 3; Table IV, Fig. 4) track found in the same outcrop. The find here considered is worthy of being stressed because tracks of reptilia in the Jurassic deposits are less abundant than in the deposits of other age, except for the Upper Jurassic lithographical limestones from Solnhofen in Bavaria. The tracks under consideration occur as castings preserved at the lower surface of sandstone slabs. One of the slabs reveals also other trails, probably also animal tracks, but less distinct (Table III, Fig. 3). Moreover, two slabs disclose some sun cracks and circular tubes, 2 - 3 mm or 5 - 7 mm in diameter. Most probably, these are tubes of worms living in mud. One of the tracks shows a cast of water-rolled wood fragment. The well preserved tracks allow us to draw conclusions that during a short period of time the deposit was emerged, probably at the ebb- tide. The tide phenomena prove also the existence of a well connection of the Lower Liassic estuarine basin with the sea. This conclusion in proved by the presence of fishes Lepidophorus angustus Agassiz (G. G. Push, 1837) and Semionotus cf. Bergeri Agassiz (Z. Maślankiewiczowa, 1965) in the deposits of this age, and by the traces of various, so far undescribed organisms found in the sandstones of the same quarry, in which the tracks have been encountered. A description of these traces is thought by the present author to be worthy of being published in the next communiqué.