Taxonomy And Biostratigraphy Of Devonian And Carboniferous Conodonts And Their Applications In Geologic Studies Of Timescale Revision, Correlations, And Depositional Environments



Journal Title

Journal ISSN

Volume Title



Conodonts are one of the most abundant and geographically widespread microfossil groups within Ordovician through Triassic sediments. Conodont biozones are some of the most precise during this interval of time and many conodonts represent stage boundary markers. Conodont biostratigraphy supports other research for correlation, stratigraphy, and the Paleozoic timescale. The publications that comprise this dissertation can be divided into two primary research themes. The first theme is advancing our understanding of conodonts and the geological timescale. Research in this theme focuses on taxonomy, ontogeny, phylogenesis, morphometrics, and biostratigraphy. The second theme is advancing our understanding of the biological, environmental, and sedimentological history of the Earth during the Paleozoic. Research in this theme uses multidisciplinary techniques to create detailed historical records of past events. Chapter 1 introduces fundamentals of conodont paleobiology and summarizes the scientific questions discussed in each published paper. Chapter 2 systematically describes the conodonts and biostratigraphy of the Englewood Formation in South Dakota, U.S.A. Four lithologic members are diagnosed and correlated to the organic-shale deposits of the Williston Basin. Chapter 3 provides a revised Tournaisian zonation and conodont range chart for North America. Chapter 4 addresses conflicting paleoclimate interpretations of petrographic data and conodont assemblages. Conodont biostratigraphy was used to revise the local correlations of carbonate packages that resolved the conflicting petrographic data. Chapter 5 advances the understanding of a historically confusing group of Late Pennsylvanian conodonts called idiognathodids. The ontogeny, taxonomy, and phylogeny of a distinct clade within this group are summarized. This work incorporated a relatively new morphometric technique specifically designed to study the shapes of Idiognathodid conodonts. These morphometric techniques continue to be used by subsequent workers and have proven helpful in taxonomic studies of conodonts.



Conodont, Biostratigraphy, Morphometrics, Paleozoic, Devonian, Carboniferous, Idiognathodus, Englewood


Portions of this document appear in: Hogancamp, Nicholas J., and Aaron P. Rodriguez. "Conodont biostratigraphy and stratigraphic framework of the Englewood Formation, Black Hills, South Dakota, USA." Stratigraphy 17, no. 2 (2020): 65-119; and in: Hogancamp, N. J., B. M. Stolfus, B. D. Cramer, and J. E. Day. "A revised conodont zonation of the Tournaisian (Kinderhookian to lower Osagean) and implications for stratigraphic correlations in North America." The Devonian-Carboniferous Boundary in the type area of the Mississippian. Iowa Geological Survey Guidebook 30 (2019): 11-17; and in: Hogancamp, N. J., and V. P. Wright. "Elucidating hydrological complexity and climate-influenced diagenesis during the early Carboniferous of South Wales." Proceedings of the Geologists' Association 132, no. 1 (2021): 93-101; and in: Hogancamp, Nicholas J. "P1 element morphological variability within the Late Pennsylvanian asymmetrical Idiognathodus clade from the Midcontinent, USA and implications for ontogeny, taxonomy, phylogeny, and function." Palaeogeography, Palaeoclimatology, Palaeoecology 549 (2020): 109090.