Abstract
Extensive surface collection and bulk sampling of a thin, iron-stained bioclastic lens (“Red Zone”) at the Austin–Taylor Group contact within the Ozan Formation of Fannin County, Texas, produced a diverse chondrichthyan assemblage comprising 29 named species plus four open-nomenclature taxa, 27 genera, and 10 orders. Most teeth are small and show little abrasion, consistent with limited transport of most recovered material. Two similar but 1 compositionally distinct chondrichthyan assemblages are recognized within the Ozan 2 Formation: one concentrated in the basal Red Zone and another extending through the remainder of the formation toward the Ozan–Kemp contact. Within the Red Zone, lamniform sharks are numerically dominant, whereas a diverse suite of batoids and other low-frequency taxa contributes substantially to taxonomic and functional diversity. The broader Ozan assemblage shares numerous taxa with middle- and late-Campanian faunas of the Western Interior Seaway, Gulf and Atlantic Coastal Plains, and Europe, supporting broad faunal interchange among connected marine provinces. The Moss Creek locality therefore provides an important record of Campanian chondrichthyan diversity, paleoecology, and paleobiogeographic connectivity along the southern Western Interior Seaway–Gulf Coastal