THE PARACHUTE CREEK ATLAS PROJECT: DECIPHERING THE FLORAL DIVERSITY OF THE GREEN RIVER FORMATION OF COLORADO AND UTAH

The Eocene Green River Formation contains one of the few fossil floras that enjoys worldwide popularity. The diversity of plant types, their often spectacular preservation, and striking beauty draws collectors of all varieties. Most of the plant fossils are collected from the oil-shales of the Parachute Creek Member which were deposited at the bottom of Lake Uinta. Despite the popularity of these plant fossils, the Eocene Green River flora of Colorado and Utah has not been revised since 1969. During the past decade, the Denver Museum of Nature & Science (DMNS) has built a large collection of fossil plants from the Parachute Creek Member by a combination of field work and donations. Using this collection, staff and volunteers have begun to re-evaluate the diversity and composition of the flora. The collection at DMNS includes over 230 morphotypes of leaves, seeds, flowers, roots, cones, and stems. The flora is dominated by dicotyledonous angiosperms, with lesser amounts of ferns, monocots, horsetails, lycopods, and conifers. The minimum diversity of the flora is 157 morphotypes based upon leaf taxa alone, which doubles the diversity of the flora as described by McGinitie in 1969. An additional goal of the project is to build a bridge between Museum and University paleobotanists, amateur and commercial collectors, and land managers. To further this goal, we are creating an internet database and website known as “PaleoCollaborator”. Objectives of PaleoCollaborator include: displaying the known diversity of the Parachute Creek fossil plant assemblage; providing an identification guide and key for fossil plants from this assemblage; soliciting information about specimens in private collections that represent new or unusually preserved species; providing a resource management tool for land owners by defining common versus rare specimens; involving interested parties in a collaborative scientific research project; and collecting data that will eventually lead to a published field guide.