EARLY PENNSYLVANIAN TETRAPOD ICHNITES OF WARREN CO., INDIANA

The rediscovery of the Cox early Pennsylvanian tetrapod tracksite in western Indiana has provided new information about the terrestrial fauna of the Illinois Basin during the early Pennsylvanian. Cox (1873) originally described Collettosaurus indianaensis from a single sandstone slab (this specimen has been misplaced) containing half a dozen tracks. Based on new material, differences in the sizes and shapes of the latest tracks recovered suggests that more than one ichnotaxa of tetrapods were present. The tracks are found in thin interbedded shales and sandstones from the Tradewater Formation along the banks of Big Pine Creek near Williamsport, Indiana. It is believed that the new material comes from more than one stratigraphic horizon. Unfortunately none of the recently discovered material has been found in situ. Geology of the site reveals that this was probably a riverine mud flat setting inhabited by a number of types of primitive tetrapods ranging from small to medium size. Also preserved on the slabs are dessication cracks and rain drops. The tracks and associated fossil plants indicates a diverse ecosystem. This fossil site reveals that the terrestrial environment of western Indiana during the early Pennsylvanian was inhabited by a more diverse vertebrate fauna than was previously believed.