Master of Science (MS)
Community Structure, Diversity, Invertebrate, Neogene
Geology; Paleontology; Paleoecology
River valleys in the Cibao Valley Basin, located in the northern Dominican Republic, expose three fossiliferous Neogene-aged strata (the Cercado, Gurabo, and Mao formations) that show evidence for shifting marine paleo-habitats. This study system is ideal for analyzing the relationships between environmental changes and faunal community stability through time. A new database was developed from the published literature to examine changing diversity patterns and to determine if the Cibao Valley communities exhibited stasis over a 3 My time span (6.5 Ma to 3.5 Ma) across shallow- to very deep-water environments. This database includes spatio-temporal occurrence data for 179 species of gastropods, bivalves, and corals. Analyses of diversity patterns reveal a high diversity of species in shallow- to deep-water depths, and a low diversity of species in very deep-water depths, as well as a low similarity of species through time across the different paleoenvironmental settings. An R-mode hierarchical cluster analysis illustrates two major clusters that were based mostly on the different paleoenvironments in which these species lived, while a Q-mode cluster analysis shows two major clusters, one consisting mostly of mollusk and the other of corals. Finally, a detrended correspondence analysis indicates higher species richness in intermediate-water depths and lower species richness in very deep-water depths. In total, these results indicate faunal instability though changing habitats across time in this study system.
Abdollahian, Nina, "Diversity and Community Structure of Marine Invertebrate Fossil Assemblages from the Neogene of the Dominican Republic" (2015). Master's Theses. 4616.