A new large-bodied species of Bothriolepis (Antiarchi) from the Upper Devonian of Ellesmere Island, Nunavut, Canada

ABSTRACT

New material from the Upper Devonian (Frasnian) Nordstrand Point Formation of Ellesmere Island, Nunavut, Canada, represents the largest known species of antiarch and the first described from the Nordstrand Point Formation. Bothriolepis rex, sp. nov., is additionally remarkable for the thickness and compactness of its dermal skeletal plates. The new species is diagnosed by a preorbital recess with a horizontal rostral margin; the presence of a wide unornamented border surrounding the infraorbital sensory line; central sensory lines that meet the margin of the nuchal close to the lateral corners; a supraotic thickening that does not extend caudal to a transverse crista of the nuchal; and a tall lateral lamina of the anterior dorsolateral. The thick and compact armor of Bothriolepis rex, sp. nov., recalls that of the co-occurring Perscheia pulla and gives occasion to a physical and ecological review of dermal skeletal mass and density in large-bodied, bottom-dwelling organisms in nonmarine ecosystems during the Late Devonian.

http://zoobank.org/urn:lsid:zoobank.org:pub:DA3A922A-4C77-4AA8-8EB7-2774333A5E96

Citation for this article: Downs, J. P., E. B. Daeschler, V. E. Garcia, and N. H. Shubin. 2016. A new large-bodied species of Bothriolepis (Antiarchi) from the Upper Devonian of Ellesmere Island, Nunavut, Canada. Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2016.1221833.

ACKNOWLEDGMENTS

The authors recognize F. A. Jenkins Jr. for his many and varied contributions to the Nunavut Paleontological Expeditions (1999–2011). The authors thank C F. Mullison and A. Visco for fossil preparation, K. Luckenbill for illustrations, J. Nark and J. Stefl for curatorial support, and K. Soldner for catalog support and German translation. S. Desbiens and J. Kerr provided collections access at the Musée d'Histoire naturelle de Miguasha. The Nunavut Ministry of Culture, Language, Elders and Youth, the Grise Fiord Hamlet, and HTA provided permits that made this research possible. The Polar Continental Shelf Project provided logistical support, and the Canadian Museum of Nature provide collections support. The authors recognize everyone who has provided field assistance on the Nunavut Paleontological Expeditions: W. Amaral, B. Atagootak, J. Conrad, R. Dahn, M. Davis, S. Gatesy, A. Gillis, B. Kilbourne, S. Madsen, K. Middleton, J. Miller, K. Monoyios, C. Schaff, M. Shapiro, R. Shearman, C. Sullivan, and M. Webster. The manuscript was improved by the comments of two reviewers, J. Long and E. Lukševičs. This research was supported by two anonymous donors; the Academy of Natural Sciences of Philadelphia; the Putnam Expeditionary Fund (Harvard University); the University of Chicago; Swarthmore College; the National Science Foundation grants EAR 0207721 (E.B.D.), EAR 0544093 (E.B.D.), EAR 0208377 (N.H.S.), and EAR 0544565 (N.H.S.); the National Geographic Society Committee for Research and Exploration grants 7223-02, 7665-04, 8040-06, and 8420-08; and Howard Hughes Medical Institute.