INSECT BONE-MODIFICATION AND PALEOECOLOGY OF OLIGOCENE MAMMAL-BEARING SITES IN THE DOUPOV MOUNTAINS, NORTHWESTERN BOHEMIA

ABSTRACT

Mammalian assemblages occur at the sites of Detan, Valec, and Dvérce in calcareous and volcanic clay layers at the southern margin of the Doupov Mountains along the Bohemian Rift. The age of the fossiliferous layer at Detan is early Oligocene (Stampian, Suevian), Biozone MP 21, and is K/Ar dated at 37.5 Ma. Mammalian bones and teeth are widely scattered within basal ash layers at Detan and show a high degree of primary fragmentation.  Bone and dentine surfaces preserved in these deposits show peculiar trace fossils on predominantly unweathered surfaces. These marks show a high degree of similarity to those seen on bones found in the Pliocene tuffaceous Upper Laetolil beds of Tanzania. They are certainly not the product of rodent gnawing. Rather, isopteran insects, most probably termites, are believed the most likely cause of the marks. The Doupovské Hory volcanics and the Upper Laetolil beds have similar calcareous tuffaceous lithologies. The distribution of plants, molluscs, and insect traces indicate a mosaic of environments during the early Oligocene in northwestern Bohemia.

Oldřich Fejfar.Charles University, Faculty of Science, Department of Paleontology, Albertov 6, Praha 2 12843, Czech Republic.
Thomas M. Kaiser. Institute and Museum of Zoology, University of Greifswald, D-17489 Greifswald, Germany.