Abstract
In the Collio Formation (Lower Permian) of the South-Apine region (North Italy) paleobiodiversity consists of tetrapod footprints, invertebrate traces and rarer plants, and is characterized by an absolute poverty of taxa that becomes more acute from the lower to the upper part of the Collio Formation. Regionally, the drop in diversity can be explained by joint tectonic and climatic change; humid evergreen environments became mainly dry. Examination of ichnofossil distribution supports this hypothesis.
ACKNOWLEDGEMENTS
The author is deeply indebted to Dr. S. G. Lucas (Albuquerque) and Dr. M. Avanzini (Trento) for critical reviews, and also to Dr. C. Krieger (Milan) and Dr. G. Papalia (Pavia) for revision of the English. This is a COFIN grant contribution (Prof. G. Cassinis).