Copyright by Nina Elise Triche 2007 The Dissertation Committee for Nina Elise Triche certifies that this is the approved version of the following dissertation: Systematics, Biogeography, and Evolutionary History of Fossil and Extant Penguins (Aves: Sphenisciformes) Committee: Timothy B. Rowe, Supervisor Christopher J. Bell Julia A. Clarke Ernest L. Lundelius, Jr. James T. Sprinkle Systematics, Biogeography, and Evolutionary History of Fossil and Extant Penguins (Aves: Sphenisciformes) by Nina Elise Triche, B.S.; B.A.; M.S. Geo. Sci. Dissertation Presented to the Faculty of the Graduate School of The University of Texas at Austin in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy The University of Texas at Austin December, 2007 Dedication To my mother, without whom I would probably not know a penguin from a pear tree. “It’s amazing, the human capacity to not notice things that you’re not interested in” —Bram Gunther, Deputy Director of Forestry and Horticulture, New York City Acknowledgements I thank my husband Eddie for keeping to a minimum his exasperation with the elaborate process of my obtaining a Ph.D., and all my friends, fellow graduate students, and family for their support. I also acknowledge all the people and institutions that helped fund my graduate career, including Ann Molineux for continual opportunities to work with fascinating though invertebrate fossils, the Jackson School of Geosciences for the equally interesting prospect of influencing the youth of our nation and for off-campus research support, summer fellowships, and matching research funds, the American Museum of Natural History (AMNH) for both a research and a collections visitation grant, and the Geological Society of America and the American Ornithologists’ Union for additional research grants. A number of museum personnel facilitated my collection visits and loans, including Joel Cracraft, Paul Sweet, Shannon Kenney, and Carl Mehling (AMNH), Sandra Chapman and Stig Walsh (Natural History Museum, London), Alan Tennyson (Museum of New Zealand, Te Papa Tongarewa), Ewan Fordyce and Tatsuro Ando (University of Otago), Sue Heath (Otago Museum), Judy St. Leger (Sea World San Diego), and Tom Webber (Florida Musem of Natural History). Thanks also to Matt Colbert and Jesse Maisano for the CT scanning and data processing of my specimens. Finally, I am grateful to my dissertation committee, Drs. Tim Rowe, Chris Bell, Julia Clarke, Ernie Lundelius, and Jim Sprinkle, for their support, their critical review, and for signing off on this work. v PREFACE The following dissertation covers the evolutionary history of penguins: their systematics, taxonomy, biogeography, and history of radiations and extinctions. Although written as a dissertation, I intend to immediately submit each chapter as a separate publication, which affects the organization of the work as a whole. Because each chapter will stand alone as a separate work, there is considerable overlap between the introductions for each chapter. Additionally, some figures and appendices, although slightly different, may present the same information from chapter to chapter. Work performed in any chapter that is cited in another appears as (Triche, Chp. X). For example, conclusions from Chapter 3, such as figured systematic hypotheses, are discussed parenthetically as (Triche, Chp. 3) in Chapter 1. The first chapter presented here is a survey of penguins in time and space, with an evolutionary overview of penguin history. Much of this chapter is excerpted for inclusion within the introductions to the remaining chapters. The second chapter describes the osteology of fossil and living penguins from the evolutionary perspective gained in Chapter 3. This third chapter comprises a phylogenetic analysis of penguin taxa and therefore uses the data presented in Chapter 2 as material but also provides the evolutionary context for interpreting the anatomy described in the second chapter. Finally, Chapter 4 is an analysis of the biogeographic and evolutionary history of penguins based on the hypothesis of phylogenetic relationships presented in Chapter 3. vi Systematics, Biogeography, and Evolutionary History of Fossil and Extant Penguins (Aves: Sphenisciformes) Publication No._____________ Nina Elise Triche, Ph.D. The University of Texas at Austin, 2007 Supervisor: Timothy B. Rowe The excellent penguin fossil record is temporally long, among the oldest of modern birds, and contains fossils on every Gondwanan continent except India. However, most of fifty-nine named taxa are isolated skeletal elements, many of which are non- comparable. Fossil diversity is highest in New Zealand, with additional Antarctic and Patagonian faunas and fewer remains from Australia and South Africa. Phylogenetic hypotheses place penguins within Aves and Neornithes, but further relationships remain contentious. Recent work clarified living species’ phylogeny, but none examined all fossil taxa. I describe penguin skeletal anatomy using CT scans and museum specimens, providing the first such description for all living and extinct species in an explicitly phylogenetic framework. All elements are phylogenetically variable, intergeneric variation is large, and extinct taxa are more variable than extant. I recommend that future systematic works include all elements for extinct species diagnoses, osteology for living vii species, and discussions of intraspecific variation. This description grounds my phylogenetic analysis, based on a 503-character matrix of osteological, myological, integumentary, and behavioral characters. This greatly expands previous datasets, and allows recovery of a highly resolved phylogeny, including monophyly of two extinct clades and the crown-group. Data partitions support different levels of relationship, whereas missing data and outgroup choice drastically affect recovered topology. Incorporating the maximum amount of data gives the highest resolution by recovering all relevant character states. I propose the first formal phylogenetic nomenclature for sphenisciforms, and define and diagnose previously used terms such as Panspheniscidae (total group), Sphenisciformes (known penguins), Spheniscidae (crown-group), Palaeeudyptidae and Paraptenodytidae (two extinct clades). I coin Spheniscoidea (Spheniscidae + Paraptenodytidae) and Australodyptinae (Aptenodytes + Pygoscelis). After calibration with geologic time, I calculate the completeness of the pencuin record and determine confidence intervals to estimate a Cretaceous origin and an Eocene crown-clade origin. These dates and the derived phylogenetic placement of penguins suggest that numerous extant bird lineages may also have Cretaceous origins. I recover a New Zealand origin for penguins and a West Antarctic origin for the crown-group and extinct clades. Correlating penguins with tectonic and climatic data indicates an Eocene adaptive radiation, probably related to latest-stage Gondwanan breakup and associated global cooling. viii Table of Contents List of Figures...................................................................................................... xiv Chapter 1 The Last Sixty-three Million Years of Penguins....................................1 Abstract ..........................................................................................................1 Introduction ....................................................................................................2 First Discoveries ............................................................................................7 Further Discoveries.......................................................................................13 South America ....................................................................................13 Antarctica.............................................................................................14 South Africa.........................................................................................18 Australia...............................................................................................19 New Zealand ........................................................................................19 Recent Finds..................................................................................................22 South America .....................................................................................22 Antarctica.............................................................................................25 New Zealand ........................................................................................29 Macroevolution.............................................................................................30 Phylogenetic Hypotheses.....................................................................30 Relationships of Sphenisciformes...............................................31 Extant Species.............................................................................34 Fossil Species..............................................................................36 Biogegraphic Hypotheses ....................................................................43 Other Patterns.......................................................................................49 Conclusions...................................................................................................57 Acknowledgements.......................................................................................58 References.....................................................................................................60