REGIONAL PALEOECOLOGY AND GLOBAL PALEOGEOGRAPHIC HISTORY OF TENTACULITOIDS

Investigations of the diversity of problematic taxa have lagged significantly, particularly dissections of paleoecological and paleogeographic patterns. Tentaculitoids specifically are an enigmatic group that are present from the Ordovician-Devonian, but their life history is unknown. Diversity studies of tentaculitoids at any scale, and paleoecological and paleogeographic analyses have never been undertaken for this group until this study.

Through an ongoing dissection of the history of tentaculitoids, a global and regional approach was conducted. The investigation involved a tentaculitoid literature-derived database to understand paleogeographic and paleoenvironmental global trends. Patterns were further dissected at the regional scale for the type Cincinnatian working under a stratigraphic framework. Bed-level samples collected from multiple stratigraphic sections were used to capture spatial and temporal distribution patterns of tentaculitoids.

Tentaculitoid diversity before this study revealed a slow rise in diversity from the Ordovician to the Devonian with a maximum of 13 genera present in the middle Devonian. However, in the updated database, tentaculitoid diversity increased dramatically to a maximum of 30 genera in the middle Devonian. The diversity trajectories appear to have been associated with radiations in particular environments throughout several paleocontinents, especially Laurentia. Tentaculitoids in the Cincinnatian demonstrate similar patterns to the global trends at finer scales indicating temporal and spatial patchiness. Both global and regional examinations reveal that tentaculitoids prefer multiple environments, are primarily abundant in diverse communities, and are important fauna in the Cincinnatian.