See more from this Division: General Discipline Sessions
See more from this Session: Paleontology I - Macroevolution, Diversity, and Biogeography
Abstract:
A database was constructed on the dimensions of specimens from museum and literature sources. Including more than 12,000 individuals; this represents the taxonomic, temporal and spatial range of the group. Comparisons with the Sepkoski database suggest that maximum and range size are positively correlated with generic diversity. Although the patterns within individual orders vary from the entire class, with the Redlichiida and Corynexochida displaying a negative correlation.
Finally, Kruskal-Wallis testing shows that trilobites undergo significant size shifts in the Cambrian, Ordovician and the Early Devonian with none in the later part of their history. The Early Devonian peak in size and diversity may in part be linked to increased predation pressure from vertebrate and ammonoid groups. Resampling of the dataset through rarefaction suggests that the patterns observed here is not a result of a sampling bias.
See more from this Division: General Discipline Sessions
See more from this Session: Paleontology I - Macroevolution, Diversity, and Biogeography