Global factors constrain body size trends across the Great Ordovician Biodiversification Event at a regional scale: a case study from the Arbuckle Mountains of Oklahoma

The Great Ordovician Biodiversification Event (GOBE) records a global increase in marine biodiversity which reached maximum diversification rates during the Middle Ordovician. The degree to which the drivers of the GOBE are regional or global is a question which must be addressed through analysis of regional data. In this study, stratigraphically constrained field-based data from the Middle Ordovician Simpson Group of Oklahoma were collected to identify temporal trends in body volume and determine whether body volume trends are more closely associated regional or global environmental and diversity changes. Volume increase was primarily associated with global-scale factors such as age, δ18O (temperature), 87Sr/86Sr (tectonics), and taxonomic diversity trends; whereas local-scale factors of Δ13C (carbon cycle) and lithologic trends were more weakly associated with local volume trends. Notably, all factors had a non-zero influence over brachiopod volume, indicating that local diversificati..., , # Global factors constrain body size trends across the Great Ordovician Biodiversification Event at a regional scale: a case study from the Arbuckle Mountains of Oklahoma

Dataset DOI: [10.5061/dryad.fj6q5746d](10.5061/dryad.fj6q5746d)

## Description of the data and file structure

Data include sedimentological data, brachiopod shell measurement data, and geochemical data.

### Files and variables

**AppendixS1.pdf** Stratigraphic columns with lithologic descriptions for all outcrops of Simpson Group strata along I-35 in Oklahoma included in this analysis.

**AppendixS2.csv** Lithologic data collected during field work for Simpson Group. Unit ID and formations match stratigraphic columns in Appendix 1. **cover and float intervals do not have unit ID #

**AppendixS3.csv** Brachiopod shell measurement data. Unit ID and formations match stratigraphic columns in Appendix 1. The quality of each measurement (length & width) was recorded as ‘A,’ ‘B,’ or ‘C’ quality according to the following ...,