A New Lower Permian Trematopid (Temnospondyli: Dissorophoidea) from Richards Spur, Oklahoma by Brendan Polley A thesis submitted in conformity with the requirements for the degree of Master of Science Department of Ecology and Evolutionary Biology University of Toronto © Copyright by Brendan Polley 2009 A new Lower Permian trematopid (Temnospondyli: Dissorophoidea) from Richards Spur, Oklahoma Brendan Polley Master of Science Department of Ecology and Evolutionary Biology University of Toronto 2009 Abstract A new trematopid amphibian, Acheloma dunni, is reported based on excellently preserved cranial and postcranial elements recovered from the Lower Permian fissure fill deposits of the Dolese Brothers Co. limestone quarry near Richards Spur, Oklahoma. The new taxon is characterized by distinct lateral exposures of the palatine (l.e.p.) and ectopterygoid (l.e.e.) completely enclosed within the suborbital elements. This large, terrestrial adapted carnivore may represent the top predator of the Richards Spur assemblage. A phylogenetic analysis including 11 ingroup taxa and 54 cranial characters yielded a single most parsimonious tree, placing A. dunni within the monophyletic Trematopidae as the sister taxon to Acheloma cumminsi. Furthermore, the analysis supports including the enigmatic Ecolsonia and Actiobates within Trematopidae, forming a clade with the Upper Pennsylvanian Anconastes and the Lower Permian Tambachia. The study is the first to comprehensively analyze all valid and aberrant forms of Trematopidae within the context of broader dissorophoid phylogeny. ii Acknowledgments I am indebted to the many individuals whose support and guidance truly enriched this challenging and rewarding year. Thank you to my supervisor, R. Reisz for being an unwavering source of encouragement and direction. As you did for me, I will be sure to have faith in my own students, treat them with respect, and push them to realize their potential. I am grateful to D. Scott for her invaluable technical training, for photographing specimens, and for, of course, her friendship. Thank you to my friends in the Reisz lab, N. Campione, J. Fröbisch, N. Fröbisch, J. Hawthorn, D. Mazierski, and N. Wong Ken for all their advice and support. Also, many thanks to my advisors D. Evans and D. Walsh for your guidance and constructive feedback. Special thanks to B. Dunn and M. Feese for their continuing efforts to collect fossils from Richards Spur. This project, among countless others, would not have been made possible without their generous donations to the Sam Noble Oklahoma Museum of Natural History. I am grateful to D. Berman of the Carnegie Museum of Natural History, Pittsburgh, PA; R. Ethington of the University of Missouri, Columbia, MO; M. Norell of the American Museum of Natural History, New York, NY; and M. Ryan of the Cleveland Museum of Natural History, Cleveland, OH for allowing me access to various trematopid specimens for study. Finally, thank you to my family, friends, and especially J. Cawaling for their unconditional love and support throughout the course of this project and beyond. iii Table of Contents Acknowledgments.......................................................................................................................... iii Table of Contents........................................................................................................................... iv List of Figures................................................................................................................................ vi List of Appendices ....................................................................................................................... viii 1 Introduction................................................................................................................................ 1 2 Materials..................................................................................................................................... 4 3 Abbreviations ............................................................................................................................. 6 3.1 Institutional Abbreviations.................................................................................................. 6 3.2 Anatomical Abbreviations .................................................................................................. 6 4 Systematic Paleontology ............................................................................................................ 7 4.1 Type Specimen.................................................................................................................... 7 4.2 Referred Specimens ............................................................................................................ 8 4.3 Diagnosis............................................................................................................................. 8 4.4 Occurrence .......................................................................................................................... 8 4.5 Etymology........................................................................................................................... 8 5 Description ................................................................................................................................. 8 5.1 General................................................................................................................................ 8 5.2 Skull Roof ........................................................................................................................... 9 5.3 Palate................................................................................................................................. 13 5.4 Braincase........................................................................................................................... 15 5.5 Lower Jaw......................................................................................................................... 16 5.6 Axial Skeleton................................................................................................................... 17 5.7 Appendicular Skeleton...................................................................................................... 18 6 Discussion ................................................................................................................................ 20 iv 6.1 Phylogenetic Analysis....................................................................................................... 20 6.2 Habits and Lifestyle .......................................................................................................... 23 References..................................................................................................................................... 26 Figures and Captions..................................................................................................................... 35 Appendix 1.................................................................................................................................... 65 Appendix 2.................................................................................................................................... 67 v List of Figures Figure 1. Reconstruction of skull of Acheloma dunni in A, dorsal view; B, ventral view; C, right lateral view. Scale = 50 mm Figure 2. Skull of Acheloma dunni, holotype (OMNH 73281) in dorsal view. Scale = 50 mm Figure 3. Skull of Acheloma dunni, holotype (OMNH 73281) in right lateral view. Scale = 50 mm Figure 4. Acheloma dunni, referred specimen (BMRP2007.3.4) in left lateral view. Scale = 10 mm Figure 5. Acheloma dunni, referred specimen (BMRP2007.3.1) in right lateral view. Scale = 10 mm Figure 6. Acheloma dunni, referred specimen (OMNH 52365). Partial right upper jaw articulation in dorsal view. Scale = 10 mm Figure 7. Skull of Acheloma dunni, holotype (OMNH 73281) in ventral view. Scale = 50 mm Figure 8. Skull of Acheloma dunni, holotype (OMNH 73281) in occipital view. Scale = 50 mm Figure 9. Partial left lower jaw of Acheloma dunni, holotype (OMNH 73281) in A, lateral view; B, medial view; C, dorsal view; D, ventral view. Scale = 10 mm Figure 10. Partial right lower jaw of Acheloma dunni, holotype (OMNH 73281) in A, lateral view; B, medial view; C, dorsal view; D, ventral view. Scale = 10 mm Figure 11. Acheloma dunni, referred specimen (OMNH 52365). Partial right lower jaw articulation in A, lateral view; B, posterior view. Scale = 10 mm Figure 12. Atlas-axis complex and associated cervical vertebrae of Acheloma dunni, holotype (OMNH 73281) in A, right lateral view; B, left lateral view; C, anterior view. Scale = 10 mm vi Figure 13. Acheloma dunni, referred specimen (OMNH 52545). Right humerus in A, posterior view; B, extensor view; C, anterior view; D, flexor view; E, proximal view; F, distal view. Scale = 50 mm Figure 14. Acheloma dunni, referred specimen (OMNH 73514). Partial pelvic girdle and hindlimb. Scale = 5 mm. Illustration by Heidi Richter. Figure 15. Single most parsimonious tree of dissorophoid relationships derived from cladistic analysis using PAUP 4.0b10 with A, relevant synapomorphies mapped on (* indicates a synapomorphy that supports the clade, but appears elsewhere in the tree); B, bootstrap (bold) and Bremer decay (italics) values calculated for the analysis; TL, tree length; CI, consistency index; RC, rescaled consistency index vii List of Appendices Appendix