XVI International Botanical Congess

Red Hill is an outcrop of the Late Devonian (Fa2c) Catskill Formation in north-central Pennsylvania. It includes a greenish-gray plant fossil-bearing siltstone layer interpreted as an oxbow lake. The parautochthonous plant fossils include Archaeopteris, Rhacophyton, cormose lycopsids, Gillespiea, Barinophyton, and both cupulate and acupulate gymnosperms. Charcoal is interspersed among the plant fossils. Paleovertisols indicate a seasonally wet-and-dry climate. Sampling and analysis indicate small-scale landscape heterogeneity of the plant community. Lycopsids grew in a multi-aged stand along the edge of the lake. Rhacophyton grew in lush stands down to the edge of the lake. Fires were of low intensity and seem to have primarily affected Rhacophyton. Gillespiea may have been early successional plant following fires. Archaeopteris branches and foliage drifted in from a presumably better-drained area of the floodplain. Red Hill is also a rich vertebrate site which includes early tetrapods. It is representative of a landscape into which the earliest tetrapods emerged.