Data from: Estimating dispersal and evolutionary dynamics in diploporan blastozoans (Echinodermata) across the Great Ordovician Biodiversification Event

Echinoderms make up a substantial component of Ordovician marine
invertebrates, yet their speciation and dispersal history as inferred
within a rigorous phylogenetic and statistical framework is lacking. We
use Biogeographic Stochastic Mapping (BSM; implemented in the R package
BioGeoBEARS) to infer ancestral area relationships and the number and type
of dispersal events through the Ordovician for diploporan blastozoans and
related species. The BSM analysis was divided into three time slices to
analyze how dispersal paths changed before and during the Great Ordovician
Biodiversification Event (GOBE) and within the Late Ordovician mass
extinction intervals. The best-fit biogeographical model incorporated jump
dispersal, indicating this was an important speciation strategy.
Reconstructed areas within the phylogeny indicate the first diploporan
blastozoans likely originated within Baltica or Gondwana. Dispersal, jump
dispersal, and sympatry dominated the BSM inference through the
Ordovician, while dispersal paths varied in time. Long-distance dispersal
events in the Early Ordovician indicate distance was not a significant
predictor of dispersal, whereas increased dispersal events between Baltica
and Laurentia are apparent during the GOBE, indicating these areas were
important to blastozoan speciation. During the Late Ordovician, there is
an increase in dispersal events among all paleocontinents. The drivers of
dispersal are attributed to oceanic and epicontinental currents.
Speciation events plotted against geochemical data indicate that
blastozoans may not have responded to climate cooling events and other
geochemical perturbations, but additional data will continue to shed light
into the drivers of early Paleozoic blastozoan speciation and dispersal
patterns.