Shifting speciation mode and biogeographic patterns during the Late Ordovician (Sandbian-Katian) in Laurentian brachiopods (Atrypida, Anazygidae)

The Late Ordovician was a period of substantial environmental change. The co-evolution of Earth systems changes involving tectonic uplift, eustasy, and biotic changes are recorded in the Late Ordovician in Laurentia. In this study, species of the brachiopod family Anazygidae within the genera Zygospira and Catazyga were analyzed to assess dispersal pathways among eight sedimentary basins. Stochastic analysis applied to a Bayesian phylogeny (Anazygidae_tree.tre) through BioGeoBEARS facilitated estimation of speciation events including episodes of vicariance and basin-to-basin dispersal events (Anazygidae_geoareas.data) within the clade. Three algorithms were implemented and compared (BioGeoBEARS_code.R). Dispersal-extinction-cladogenesis (DEC) + jump dispersal parameter was the best supported model. For suggestions, advice, or requests related to the code and how to re-run our results, please contact the author. 
Results (b_AICc_table.csv) indicate that Anazygidae originated from an..., , # Shifting speciation mode and biogeographic patterns during the Late Ordovician (Sandbian-Katian) in Laurentian brachiopods (Atrypida, Anazygidae)

Dataset DOI: [10.5061/dryad.d51c5b0fs](10.5061/dryad.d51c5b0fs)

## Description of the data and file structure

### Files and variables

#### File: BioGeoBEARS\_code.R

**Description:** R code used in R 4.3.0 with original (Matzke, 2013) and adapted comments

#### File: Anazygidae\_geoareas.data

**Description:** Anazygidae_geoareas.data is the file used in the R script. It's a .txt file saved as .data.

The first line contains the number of analyzed taxa (20), the number of total geographic areas (8), and the initial letters for each studied geographic area. Presence/absence of the taxa in a given geographic area is given by 0 (absence) or 1 (presence).

O = Scoto-Avalonia; W= Western Mid-Continent; U= Upper Mississippi Valley; E= Eastern Canada; F= Proximal Foreland basin; N= Northern Appalachian Basin; S= Southern Appalachian Basin; a...,