PALEOZOIC BRACHIOPOD DISTRIBUTIONS

Ecological models often predict different fundamental structures of relative abundances among organisms from the same community. Scientists have investigated whether these structures differ (and the extent to which they differ) over very large scales: e.g., different environments or even different periods of the Phanerozoic compared to other eras. What has not been worked on in a larger scale is the variation in sampled community structure among fossil assemblages of similar species from the same rock-units or from contemporaneous rock-units. Examining variations in abundance distributions among contemporaneous assemblages can assess how “consistent” general ecological rules are over limited areas and time spans. Under “metacommunity” theory, we might expect differences in abundance distributions to reflect chance differences in sampling (by paleontologists of fossils, but also in the assembly of local communities from the larger metacommunity). If local environmental factors are important, then we might expect to see consistent types of differences in abundance distributions. This is all to say that distributions looking into Paleozoic fauna have not been as specialized into analyzing regions in small groups of time. With that In mind my research has the goal of looking into the undocumented whole-fauna collections in the Invertebrate Paleontology collections at the State Museum of Nebraska. This work has precedence compared to previous distribution studies, due to it being a different way to view older data. This can allow us to better understand variation in sampled community structure and local environmental factors. The goal of this work is to better understand the samples we have available, and how accurate our models are of fossil assemblages of similar species from the same rock-units or of contemporaneous rock-units.