NEW CONTRIBUTION TO THE PALAEOICHNOLOGY AND TAPHONOMY OF THE AHNÍKOV FOSSIL SITE, EARLY MIOCENE, MOST BASIN (THE CZECH REPUBLIC).

The material of Machichnus regularis and Machichnus multilineatus was re-examined with respect to the potential tracemaker. New characters were defined for M. multilineatus - scratch profile with flat horizontal bottom and undulated microrelief of scratches. Based on these characters and additional information, both previously suggested tracemakers (beavers and porcupines) are rejected and a new one - a large squirrel is proposed. The squirrel origin of gnawing traces is additionally supported by actuopalaeontologic study on gnawing behaviour of recent red squirrels. On this basis, squirrels are recognized as overlooked but important taphonomic agents in Late Cenozoic assemblages. The tracemaker of M. regularis was not unambiguously recognized, but a connection with smaller squirrel or aplodontid species seems probable. [ABSTRACT FROM AUTHOR]