THE 1ST 2 MILLION YEARS AFTER THE CRETACEOUS-TERTIARY BOUNDARY IN EAST TEXAS - RATE AND PALEOECOLOGY OF THE MOLLUSCAN RECOVERY

Analysis of molluscan collections from a 3+ m.y. interval around the Cretaceous-Tertiary (K-T) interval in east Texas suggests that molluscs suffered an extinction at or near the K-T boundary, followed by a prolonged period of stress which lasted through the PO and P1a planktic foraminiferal zones. The stressed period was characterized by low species richness, low abundances of individuals, high species turnover and a dominance of deposit feeders. Species richness and the relative abundance of deposit feeders generally track the C-13 depletion curve suggesting that the stress was caused by a lack of primary production. A stable, relatively diverse, suspension feeding molluscan community was reestablished less than two million years after the K-T boundary. The total number of species within the habitat did not recover to Cretaceous levels within the study interval.