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W. David Liddell






Preparing to dive in Nekton Gamma at Lee Stocking Island, the Bahamas

Stalked crinoids and sediment traps at 300m, Jamaica

Pisces submersible on a dive at Jamaica


Research Interests


Within the broad field of sedimentary geology and paleoecology my research interests have largely centered on modern carbonate environments, Paleozoic hard substrata communities, taphonomy and sequence stratigraphy.


My studies on carbonate environments have been directed toward the following: (1) evaluating the physical and biological factors influencing reef and adjacent deep-water hard substrata community structures; (2) developing models for the evaluation of change in reef communities and documenting long-term trends in such communities; (3) developing microfacies models for Holocene environments (fringing reef, lagoon and basin settings) which utilize macrofaunal, microfaunal, taphonomic, and sedimentologic data; and (4) determining the food and habitat requirements of certain extant marine groups (e.g. crinoids), which may aid in understanding the paleobiology of their fossil counterparts.


My studies of hard substrata communities have been focused on delineating diversity patterns throughout the Paleozoic and have included studies of Cambrian and Ordovician hardground communities, competition for space between Silurian epizoans, and cryptic communities inhabiting Silurian and Devonian bioherms. Ultimately, such studies may extend into the Mesozoic and Cenozoic Eras in order to compare the temporal patterns (diversifications, extinctions) displayed by these evolutionarily-conservative communities to those of other marine benthos.





Modern stromatolites at 3m, Lee Stocking Island, the Bahamas

Azooxanthellate (ahermatypic) coral Tubastrea aurea at 20m, Rio Bueno, Jamaica.

Foraminifera in thin section of deep sea sediment sample



My taphonomic studies have largely examined foraminifera and the effects of transportation and test destruction upon preserved foraminiferal biofacies.


My students and I are currently working on the sequence stratigraphy of Middle Cambrian rocks in Utah (especially the Spence and Wheeler Shales). We are examining the effect of sea-level oscillations on litho-, bio- and taphofacies.


Another new area of research is the influence of stratigraphy and geologic structures on the formation of alpine cave systems.


In the above research endeavors, I have attempted to fully involve my graduate students in all aspects of the research, from planning and initial field work to ultimate publication. In addition, I have included undergraduates in several of my research projects (note student-authored articles in Publications).






Soft-sediment deformation in slope sediments, Cambrian Wheeler Fm, House Range, Utah

Zacanthoides liddelli Cambrian trilobite from the Spence Shale, Utah

Cambrian Wheeler and Pierson Cove Fms in the Drum Mts, Utah




Giant stromatolite in the Cambrian Wheeler Fm, Drum Mts, Utah

Measuring strike and dip on bedding and joints in BRG Cave, Tony Grove area, northern Utah