ECOLOGY AND THE EVOLUTION OF ANTI-PREDATORY MORPHOLOGY WITHIN BUSYCONINE WHELKS: A PLIOCENE TO RECENT PERSPECTIVE A Dissertation Presented to the Faculty of the Graduate School Of Cornell University In Partial fulfillment of the Requirements for the Degree of Doctor of Philosophy By Mary Elizabeth Kosloski August 2012 © 2012 Mary Elizabeth Kosloski ABSTRACT ECOLOGY AND THE EVOLUTION OF ANTI-PREDATORY MORPHOLOGY WITHIN BUSYCONINE WHELKS: A PLIOCENE TO RECENT PERSPECTIVE Mary Kosloski, Ph.D. Cornell University 2012 My dissertation focuses on the ecological circumstances associated with the evolution of heavily ornamented morphologies within Busyconine whelks. Busyconine whelks display a variety of shell forms in the Recent and fossil record, with heavily ornamented shells concentrated in the southern part of the modern species Busycon carica’s range. In the fossil record, heavily ornamented shells recur in temporally disjunct populations over variable geographic extents from the Pliocene onwards. I investigated the function of shell sculpture (such as the tumid ridge, increased shell thickness, and spines), as well as fitness costs (such as reduced growth) associated with producing and maintaining heavily ornamented shells. I used stable isotopes to construct growth curves, and compared growth estimates to prior studies throughout B. carica’s range. In modern populations of B. carica, increased ornamentation confers a significant benefit when dealing with shell crushing predators. Growth curves constructed from stable isotopes show a latitudinal trend in growth rates, with slower growth in northern populations, and also revealed diminished growth in the south within populations for heavily ornamented individuals, as compared to weakly ornamented individuals. Some prior growth studies have ignored episodicity of growth in Busycon; this has led to inaccurate estimation of rates. Future work should focus on both incorporating intervals of non-growth into models derived from mark- recapture studies, and also on further examining growth costs associated with the development of heavily ornamented morphologies. This work also highlights the importance of standardizing for growth rates, body size, and degree of ornamentation when calculating repair frequencies. In the fossil record, adaptations are best developed in the Pliocene, and diminish sharply in abundance across the Plio-Pleistocene boundary coeval with a regional extinction event. The use of an ecometric approach, which advocates using the presence or absence of traits to assess environmental and ecological conditions, suggests that the maintenance of adaptations following the extinction event was diminished, likely as a combined response to both deteriorating environmental conditions and lower predation rates. Higher predation rates and more permissive environmental conditions in the late Pleistocene and Recent are correlated with increased abundance of defensive features. BIOGRAPHICAL SKETCH Mary was born in Buffalo, New York in 1984 and grew up in Tonawanda, New York, where she was privileged to have access at a young age to the abundant Devonian fossil fauna of the region. Her father, an avid fisherman, took Mary and her sisters Carol and Sarah on many fossil expeditions in Eighteen Mile Creek, where he divided his time between catching bass and helping the girls identify their fossils. At Eighteen Mile Creek, Mary learned to recognize both concretions (including western New York’s “turtle rocks”) and the brachiopod Mucrospirifer mucronatus, and spent many fruitless hours scanning the gorge walls in hopes of discovering the area’s first Tyrannosaurus rex skeleton. These trips fueled her childhood ambition of becoming a paleontologist. Mary initially started college at SUNY Geneseo in 2002 with the intention of pursuing a degree in Elementary Education with a French minor. After taking a course on Historical Geology during her first semester with Dr. D. Jeffrey Over, she became increasingly interested in Paleontology and Geology. Over the next few semesters, Mary took several more courses in Geology, and then switched to a Geology major at the end of her sophomore year. At Geneseo, she completed a senior Honors Thesis under Dr. Over’s advisement on a conglomeratic lag deposit in a local sandstone complex. In 2006, Mary began her pursuit of a PhD at Cornell University in Ithaca, New York. iii DEDICATION My dissertation is dedicated to my parents, Janet and Victor Kosloski, who have supported me in every sense of the word for the past 27 years. Thank you for telling me always that I could be anything I wanted, thank you for sharing your love of nature, thank you for taking me camping, and thank you for being not just my parents, but also my friends. You two are the very best. iv ACKNOWLEDGMENTS Financial support for my research has come from several sources: a Cornell Graduate School Travel Research Grant, a Lerner-Gray Grant for Marine Research from the American Museum of Natural History, a Conchologists of America Student Research Grant, and a Paleontology Society Ellis L. Yochelsen Student Research Grant. At Cornell, I have been supported by a McMullen Fellowship, numerous TA appointments through the Department of Earth and Atmospheric Sciences, research assistantships through the Paleontological Research Institution, and through the Engineering Learning Initiatives program as a TA trainer and as the TA Fellow. Conference travel while at Cornell has been generously supported by the Department of Earth and Atmospheric Sciences Kaufmann Grant, the Paleontological Research Institution, and the Cornell Graduate School. I have also received support in my research from the University of Georgia’s Marine Extension Service, particularly Alan Power, Randal Walker, and Brian Corley. Brian took me out in the salt marshes to hunt for whelks on several occasions, and other members of the team provided both shells and data that I could not have completed my dissertation without, while additionally providing a long record of outstanding research on whelks. Jerry Harasewych at the Smithsonian National Museum of Natural History, Lauck Ward at the Virginia Museum of Natural History, Leslie Skibinski at the Delaware Museum of Natural v History, and Karen Walker and Irvy Quitmyer at the Florida Museum of Natural History all provided access to collections throughout my dissertation. The program PAST is freely available, and has been a great help in various statistical analyses carried out throughout this body of work. I have been incredibly fortunate in my mentors, educators, and friends over the past 27 years, and could not have gotten through the past six years without the tools and support that they have given me. In middle school, Grace Lawrence was both an excellent teacher, and a memorable example of a female naturalist. At Kenmore East High School, Ralph Critelli sparked my interest in the Earth Sciences by both creating engaging lectures, and by organizing a hundred- student plus earth-science and white water rafting weekend. I suspect strongly that his efforts at making science interesting, exciting, and fun are largely if not almost solely responsible for Kenmore East High School’s high output of geologists. At Geneseo, during Freshmen Orientation, William Edgar and his wife, Stacey Edgar, recommended that I take a course in Earth Sciences with D. Jeffrey Over to fulfill my sciences requirement. This course re-introduced me to Geology and Paleontology after a long gap, and I am so thankful that the Edgars pointed me towards it. Jeff has served as a wonderful mentor and advisor, both during my initial four years at Geneseo as an undergraduate as well as this fall, when I had the opportunity to return and teach as an adjunct. He has also demonstrated just how vi good a very well delivered lecture could be, and has been an excellent example of I aspire to be as a professor. Scott Giorgis, Dori Farthing, Amy Sheldon, Richard Hatheway, and Richard Young also provided really wonderful support and mentoring throughout my time at Geneseo. At Cornell, I am hugely indebted to Snee’s very excellent staff. Of particular import, Steven Gallow has more than once saved me from technological disasters of epic proportions, and Savannah has provided the logistic and emotional support necessary to get through a dissertation. Linda Tompkins and Teresa Jordan have also both been a constant source of encouragement and kind advice. My committee members, John Cisne and Catherine Drew Harvell, have helped me to think outside of the somewhat narrow scope of a dissertation, while providing feedback that improved hugely the quality of this manuscript. Greg Dietl introduced me to both Busycon and field work in the Coastal Plains, and has served as an incredible example of a scientist as well as a really wonderful mentor. Warren Allmon has provided energy and encouragement, and has always looked out for my best interests even when I had no idea what they were. He has also supported my pursuit of all sorts of teaching opportunities and experiences, and I could not have lucked into a better role model or a more supportive advisor for going into academia. I have been privileged to work with all of you, and have benefited greatly. I have also been privileged to be a part of the Snee student community, and am particularly grateful for the friendships of Tiffany Tchakirides, Greg Kirkpatrick, Steve Holtkamp, Sander Hunter, Gregg McElwee, Brita Lorentzen, and Veronica Prush. Steve vii Durham and Dana Friend have very kindly tolerated me as an office mate during the past year as I’ve written up, and have been very fun to work with. I’m excited that they will be carrying on the Paleontology tradition at Cornell—you two are great. Outside of the department, Sandy LaBuda and Sarah and Jake Clements have been some of my very best friends for a decade and more, and have been everything from great listeners to really fun breaks from work to second homes. I hope we remain friends for all of the rest of the decades, too.