Date of Degree
MS (Master of Science)
First Committee Member
Second Committee Member
Third Committee Member
Fourth Committee Member
Recent inquiry into the nomenclature of several species within Spinocyrtia has led to questions concerning name applicability and validity, particularly whether Delthyris granulosa and Spinocyrtia (Spirifer) granulosa are synonymous. This study utilized two-dimensional outline landmark analysis, a form of geometric morphometric analysis, to evaluate interspecific variation among these species. I took over a thousand photographs of over a hundred specimens of brachiopods belonging to the family Spinocyrtiidae. Ninety-six specimens originated from the Givetian outcrop belt of New York state, three were from northwestern Ohio, there was single Canadian specimen, and there was a single German specimen. The results from these analyses indicate that the mophospaces of Spinocyrtia (Spirifer) congesta, S. (Spirifer) granulosa, and S?. (Spirifer) marcyi are statistically (p < 0.05) distinct from one another.
Brachiopoda, Devonian, Geometric Morphometrics, Landmarks, Principal Component Analysis, Spinocyrtid
ix, 46 pages
Includes bibliographical references (pages 20-23).
Copyright © 2017 Alexander Patrick Layng
Layng, Alexander Patrick. "Two-dimensional landmark analysis of Spinocyrtid brachiopods of Euramerica during the Givetian." MS (Master of Science) thesis, University of Iowa, 2017.
Additional FilesMakeFan_Images.zip (28658 kB)
Specimen_labels.zip (173288 kB)
tps_landmark_files.zip (118 kB)
Dorsal.zip (435042 kB)
Stackshot Images Dorsal
Test Images (42-45).zip (186829 kB)
Stackshot Images Test Images
Ventral.zip (614830 kB)
Stackshot Images Ventral