See more from this Division: Topical Sessions
See more from this Session: After the Last Ammonite and before the First Horse: Patterns of Ecological and Climatic Change during the Paleocene
Abstract:
Increased resolution in calibration techniques and changes in molluscan sampling methods in recent years resolves a more detailed and unique record of Paleocene molluscan evolutionary changes. However, some NALMA are not well known, with few localities from early early and early mid Paleocene strata (Pu1, To1). These intervals are sufficiently represented to suggest causal mechanisms for apparent low diversity.
The Cretaceous-Paleogene event resulted in few continental molluscan survivors. Certain species can be tracked across the boundary, and evolutionary changes can be seen in a few lineages but, in general, continental molluscan diversity crashed from the high numbers near the end of the Cretaceous. Interpreting the recovery of molluscan diversity is complicated by two factors: 1) the loss of diversity at the end of the Cretaceous was fundamental because certain morphological designs were lost and 2) Paleocene molluscan diversity remained relatively low throughout the duration of the Cannonball Sea. With the final retreat of the Cannonball, snail-dominated diversity increased dramatically in mid late Paleocene (Ti3) and remained high throughout the remainder of the Paleocene.
See more from this Division: Topical Sessions
See more from this Session: After the Last Ammonite and before the First Horse: Patterns of Ecological and Climatic Change during the Paleocene