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The Pennsylvania State University Schreyer Honors College THE PENNSYLVANIA STATE UNIVERSITY SCHREYER HONORS COLLEGE DEPARTMENT OF SCIENCE EARLY CAMPANIAN ELASMOBRANCH ASSEMBLAGE FROM NORTH CAROLINA WITH PALEOECOLOGICAL AND PALEOBIOGEOGRAPHICAL IMPLICATIONS TAYLOR A. KIGHTLINGER SPRING 2017 A thesis submitted in partial fulfillment of the requirements for a baccalaureate degree in General Biology with honors in Biology Reviewed and approved* by the following: Todd Cook Professor of Paleontology Thesis Supervisor Michael Campbell Professor of Cell Biology Honors Adviser * Signatures are on file in the Schreyer Honors College. i ABSTRACT Recently, a new sclerorhynchid sawfish, Borodinopristis shannoni, was described from an early Campanian (± 80 million years ago) fossil site near Elizabethtown, Bladen County, North Carolina, USA. At the time of recovery, a large assemblage of additional elasmobranch remains, mostly teeth, was also collected. Preliminary examination of the fossil material revealed a rich diversity of shark and ray species in this region of the eastern seaboard, pertaining to this particular stage of the Cretaceous period, that had not been previously well-assessed. By comparing this Elizabethtown assemblage to slightly younger assemblages, changes in regional faunal composition over a relatively short amount of geological time were inferred. These Elizabethtown fossils were also evaluated with contemporaneous assemblages from Europe, northern Africa, and Australia to determine whether a species had cosmopolitan or regional ranges. ii TABLE OF CONTENTS LIST OF FIGURES .................................................................................................... iii ACKNOWLEDGEMENTS ......................................................................................... v Chapter 1 Introduction ................................................................................................. 1 Sub-Chapter 1 Geology ........................................................................................ 2 Sub-Chapter 2 Materials & Methods .................................................................... 3 Chapter 2 Systematics ................................................................................................. 4 Lonchidion babulski .............................................................................................. 4 Hybodus sp. ........................................................................................................... 4 Squantina hassei ................................................................................................... 4 Plicatoscyllium globidens ..................................................................................... 5 Scapanorhynchous texanus ................................................................................... 5 Cretalamna appendiculata ................................................................................... 6 Archeolamna kopingensis ..................................................................................... 6 Squalicorax kaupi ................................................................................................. 6 Squalicorax pristidontis ........................................................................................ 7 Ischyrhiza mira ..................................................................................................... 7 Pseudohypolophus ellipsis .................................................................................... 7 Rhombodus laevis ................................................................................................. 8 Brachyrhizodus wichitaensis ................................................................................ 8 Chapter 3 Discussion .................................................................................................. 12 LITERATURE CITED ................................................................................................ 14 iii LIST OF FIGURES Figure 1. Stratigraphy of Black Creek ................................................................................... 2 Figure 2. Elasmobranchs ....................................................................................................... 9 Figure 3. Lamniformes ........................................................................................................... 10 Figure 4. Batoids ..................................................................................................................... 11 iv ACKNOWLEDGEMENTS I express my utmost gratitude to Gerard Case for providing the fossil specimens, to Jerome Magraw of Penn State Behrend for his assistance with the SEM imaging, and to Dr. Michael Campbell of Penn State Behrend, my honors advisor, for reviewing an early draft. The completion of this thesis would not have been possible without Dr. Todd Cook, my research advisor. He has continually offered encouragement toward my success on this project, my education, and overall career goes. I bestow my sincerest appreciation for the learning and publication opportunities that the Penn State Behrend 2016 Undergraduate Student Research Grant has given me. I am grateful for the supportive School of Science staff at Penn State Behrend, as well. 1 Chapter 1 Introduction Chondrichthyans (cartilaginous fishes) include the elasmobranchs (sharks, rays, skates, and sawfish) and holocephalans (chimaeras). The fossil record of this group is well-known but is largely restricted to hard elements that preserve readily, such as teeth, scales, and spines. The dental morphology of elasmobranchs is species specific and is used in identification process and to provide paleoecological and paleobiogeographical insights. Recently, a new sclerorhynchid sawfish, Borodinopristis shannoni, was recovered from a productive early Campanian (ca. 80 Ma) fossil site near Elizabethtown, Bladen County, North Carolina, USA (Case et al., 2012). At the time of recovery, a large assemblage of additional elasmobranch remains (largely teeth) was also collected. Very little is known of shark and ray diversity in this region of the Eastern seaboard during this particular stage of the Cretaceous period. Cicimurri (2007) described a late Campanian (ca. 76 Ma) assemblage from South Carolina that included species belonging to 18 different genera. By comparing the latter assemblage with the recovered assemblage from Elizabethtown, we will examine the changes in regional faunal composition over a relatively short amount of geological time. By comparing the occurrence of species at Elizabethtown with contemporaneous assemblages from Europe, northern Africa, and Australia, we will be able to determine whether species had cosmopolitan or regional ranges. 2 Sub-Chapter 1 Geology The elasmobranch assemblage was recovered from the Bladen Formation in an exposed landfill pit near Elizabethtown, Bladen County, North Carolina, USA. This formation, which overlies the Tar Heel Formation and underlies the Donoho Creek Formation, represents a delta-shelf system and largely consists of feldspathic quartz sandstone and dark clay (Sohl and Owens 1991). Based on palynological data, the Bladen Formation is likely middle Campanian in age (Prowell et al. 2003). Figure 1. Geographical and stratigraphic map of the Elizabethtown site (image taken from Case et al., 2012) 3 Sub-Chapter 2 Materials & Methods Teeth and rostral spine specimens were collected by sieving and handpicking. To dissolve remaining sediment or matrices, they were immerse in an acetic acid solution. Considerably small teeth were gold-coated and imaged using a Hitachi S-2500 Scanning Electron Microscope. Larger specimens were coated with ammonium chloride and photographed using a Canon EOS Rebel T6 50mm compact- macro lens camera. 4 Chapter 2 Systematics Chondrichthyes Huxley, 1880 Elasmobranchii Bonaparte, 1838 Euselachii Hay, 1902 Hybodontiformes Maisey, 1975 Lonchidion Estes, 1964 Lonchidion sp. (Fig. 2; A1, A2) The crown mesodistally elongated and labiolingually flat. Both labial and lingual crown faces are smooth. There is a moderate central protuberance on the labial crown face. The root is missing. Hybontidae Owen, 1846 Hybodus Agassiz, 1837 Hybodus sp. (Fig. 2; B1, B2) The crown consists of a tall median cusp and a two pairs of small lateral cusplets. Both labial and lingual faces are convex and separated by a smooth cutting edge. Strong enameloid folds extend from the base to approximately half the median cusp height. Folds associated with the lateral cusplets extend to the apex. The root is missing. Neoselachii Compagno, 1977 Squalomorphii Compagno, 1973 Squantiformes Buen, 1926 Squantinidae Bonaparte, 1838 Squantina Dumeril, 1806 Squantina hassei Leriche, 1929 5 (Fig. 2; C1, C2) The crown contains a triangular median cusp with a sharp apex and a wide base. The labial and lingual crown faces are smooth and separated by a cutting edge. The heels are oblique and separated from the cusp. The base of the labial crown has a well-developed apron. The lingual crown face has a lingual protuberance. The root is damaged but is relatively triangular basally and has a large central foramen. Orectolobiformes Applgegate, 1972 Ginglymostomatidae Gill, 1862 Plicatoscyllium Case and Cappetta, 1997 Plicatoscyllium globidens Capetta and Case, 1975 (Fig. 2; D1, D2) The crown contains a lingual directed median cusp and one pair of short lateral cusplets. The labial face contains enameloid folding and has a broad apron basally. The lingual face is smooth and has a medio- lingual protuberance. The root
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