A PRELIMINARY INVENTORY AND ASSESSMENT OF ICHNOFOSSILS FROM THE GREEN RIVER FORMATION

The Green River Formation contains one of the best preserved lacustrine Konservatt-Lagerstätten in the world, revealing extensive information about Eocene fauna, flora, and paleoenvironments. Geologists and paleontologists have studied the Green River Formation and its exceptionally well-preserved fossils for more than a century. Near shore and terrestrial facies of the lake systems yield a wide variety of ichnofossils that significantly contribute to paleoenvironmental and paleoecological interpretations. Although current studies indicate that ichofossils are abundant throughout the formation, only nominal research has been conducted in the past. An inventory and assessment of the ichnofossil resources in the Green River Formation was initiated in 2002 to enhance our understanding of this paleoecosystem.

Objectives of the study focused on ichnofossil locality documentation, ichnotaxonomic description, and diversity. A preliminary assessment of their utility for paleoenvironmental interpretations was undertaken, with particular attention to the potential for ichnostratigraphy in the Green River Formation and effectiveness for evaluating paleoenvironmental trends.

Ichnofossils in the Green River Formation represent a valuable source of new paleoenvironmental and paleoecological data useful for expanding our knowledge of Eocene bionetworks. Although this study was limited to vertebrate and invertebrate tracks and burrows, data suggests that a broader assessment of other ichnofossil groups is warranted.