Paper No. 76-11
Presentation Time: 9:00 AM-5:30 PM
A NEW GONDWANAN CRINOID FAUNA FROM THE UPPER ORDOVICIAN (KATIAN) OF SPAIN: SYSTEMATICS AND PALEOBIOGEOGRAPHIC IMPLICATIONS
The Ordovician was a critical interval in the evolutionary history of crinoids, encompassing both the initial diversification of the class and its subsequent radiation during the Great Ordovician Biodiversification Event. Sampling of crinoids from Ordovician paleocontinents is uneven with a disproportionate number of faunas described from Laurentia. For this reason, improved sampling of non-Laurentian faunas is essential for understanding both evolutionary dynamics and paleobiogeographic patterns of Ordovician crinoids. Here, a diverse crinoid fauna is described from the Upper Ordovician (Katian) Fombuena Formation from the eastern Iberian Chains of Spain. Taxa recovered include four new diplobathrid camerate genera, one new cladid genus, and a new species of the monobathrid camerate Eopatelliocrinus. The crinoids from the Fombuena Formation represent a cool-water Gondwanan assemblage from a high paleolatitude with the highest crinoid diversity known from the Katian of Gondwana. In addition to improving sampling from non-Laurentian Ordovician paleocontinents, description of the Fombuena Formation crinoids serves to broaden understanding of global changes in both paleobiogeography and taxonomic composition of Upper Ordovician crinoid faunas.