Paleocommunities of the Yorktown Formation (Pliocene) of Virginia

The distribution of fossil communities within the profusely fossiliferous Pliocene aged strata of the Atlantic Coastal Plain can be used to test the structural stability of fossil communities through time and to explore how community structure may change over both short and long time scales. Because these strata also record a number of sea level fluctuations, knowledge of the environmental signatures preserved in the fossil communities contained therein can be used to address a second major problem: the degree to which details of sea level change are recorded in the sedimentary record of a passive continental margin. Before determining whether communities remain stable over long periods of time in the Cenozoic (a fundamental question for evolutionary paleoecology), or using these fossil communities to track the pattern of environmental shifts during Pliocene sea level fluctuations (a crucial issue in stratigraphy), techniques designed to analyze the structure of fossil communities both within and between stratigraphic units must be applied.

Over the last 5 years, I have sampled the Yorktown Formation at several places on the Atlantic Coastal Plain of Virginia to address these issues (click here for a discussion of the sampling protocol and details of the data set itself). My data set has been used to specifically address:

• How can a grossly fossiliferous formation like the Yorktown be sampled for paleocommunity analysis (click here for more)?
• What is the paleocommunity structure of the Yorktown Formation (click here for more)?
• Are the strong species interactions necessary for "ecologic locking" to be a viable mechanism for maintaining coordinated stasis recognizable in the Yorktown paleocommunities (click here for more)?
• What recurs consistently in the Yorktown Formation, if not the individual species (click here for more)?