LATE SILURIAN–EARLY DEVONIAN GASTROPOD PALEOBIOGEOGRAPHIC AFFINITIES OF ALASKAN TERRANES: BIOLOGICAL, PALEOGEOGRAPHICAL AND SAMPLING CONSTRAINTS

Recent studies on the Silurian–Devonian paleobiogeographic affinities of Alaskan terranes have suggested that some of these terranes (i.e., Farewell, Livengood, and Alexander terranes) represent continental margin sequences that have been rifted away from the Siberian continent. Detailed taxonomic inventory of Late Silurian-Early Devonian gastropods has provided a new possibility to numerically re-analyze available data. Special attention is paid to evaluation of sampling bias as well as to analysis of dispersal capability of gastropod species based on their early shell ontogeny. Results of the paleobiogeographic analysis are compared with recent paleogeographic models.