A STATISTICAL APPROACH TO UNDERSTANDING DIVERSITY IN AN UPPER MISSISSIPPIAN (CHESTERIAN) ECHINODERM-RICH UNIT ACROSS FOUR CONTIGUOUS LITHOFACIES, CARTER COUNTY, NORTHEASTERN KENTUCKY
Examining richness (total individuals/area) and using Simpson’s Index of Diversity and Shannon’s Evenness Index, we derived richness (S), diversity (D) and evenness (EH) data for each lithofacies. Then Pearson’s r, a value ranging from 0 (none) to 1 (strong), was adapted to show degree of strength or weakness of values for each index. On a gradient from shallow to deep, shoal calcarenites show that S=363/m², D=0.89 and EH =0.71; shoal-margin calcarenites show that S=419/m², D=0.66 and evenness EH =0.57; transitional calcarenties/calcilutites show that S=327/m², D=0.90 and EH=0.84; and basinal calcilutites show that S=1024/m², D=0.92 and EH =0.76. For the entire collection, S=467/m², D=0.90 and EH =0.69. These data suggest that in the entire collection, richness is somewhat strong, diversity is strong, and taxa are uniformly abundant. Basinal environments are richest and most diverse, but taxa were not uniformly abundant. In contrast, the transitional environment shows the lowest richness, but strong diversity and uniform abundance of taxa. Although studying echinoderms was the original purpose of the study, derived statistical data like these provide context in which to understand the relative abundance and functions of echinoderms within their communities.