Terrestrial biota in coastal marine deposits: fossil-Lagerstنtten in the Pennsylvanian of Kansas, USA

The fossil animal assemblages of three Pennsylvanian marine Lagerstنtten of Kansas are compared. Detailed taphonomic investigations and comparison of total fossil assemblages are the most reliable for palaeoenvironment interpretation. Functional morphology, taxonomic uniformitarianism, behavior, absence of marine fossils (for freshwater), and palaeogeography are weak criteria of a hypothesis of freshwater depositional environment based on the assumption that closely related taxa have similar environment preferences, functions, and behaviors. In general, invertebrates, being less mobile, are better indicators of their general environment than vertebrates. Terrestrial vertebrates can dominate the fossil vertebrate assemblage of a clearly marine depositional palaeoenvironment. As long as acceptable indicators of Palaeozoic freshwater environment are not found, the hypothesis of freshwater environment cannot stand the test, only easily falsified by the discovery of marine fossils. Fishes may indicate marine connectedness, not necessarily a marine depositional environment.