Undergraduate Student Research
Theses — 2003-Present
Cortez, Karla – Joint morphology in turtles: implications for reconstructing joints in fossil sauropsids.
DeLuka, Jennifer – Investigation of uncinate process diversity and distribution in avian species: implications for uncinate process evolution.
Diedrick, Megan – Diversity of tooth shape in mustelids (co-advisor: Dr. Jessica White, Sociology / Anthropology)
Gardener, Christine – Long bone scaling across Afrotherian mammals: a geometric morphometric approach.
Kuberski, Melissa – Investigation of variability in living reptile sacra: implications for functional morphology.
McMinn, Kelly – Geometric morphometric analysis of otter teeth (co-advisor: Dr. Jessica White, Sociology / Anthropology)
Parks, Hillary – Anatomy of the first cervical vertebra and implications for the evolution of bipedalism (co-advisor: Dr. Jessica White, Sociology / Anthropology)
Reiss, Katie – Allometric growth of the caudal fin in Squalus acanthias (co-advisor: Dr. Tim Spier)
Schallhorn, Michelle – Ulna morphology and development of the olecranon process in mammals and reptiles.
Schuenman, Kim – Geometric morphometric scaling of felid (domestic and wild cat) limbs.
Smith, Amanda – The effect of epiphyseal cartilage loss on Trachemys scripta turtles and its implications for inferences of fossil reptile locomotion.
Sylvester, Mary Nikky – Geometric morphometric analysis of Colubroid snake head morphology: implications for phylogeny and ecology (co-advisor: Dr. Jessica White, Sociology / Anthropology)
VanBuren, Collin – Correlating radius bone shape with limb posture in mammals and reptiles.
Independent Study – 2003 to Present
Coghill, Lyndon – Morphometric variation in boiid and python skulls.
Hoskins, Aubrey – Clearing and staining small vertebrates and vertebrate embryos.
Lefever, Daren – Vertebrate skeletal reconstruction, Oppossum skeleton (Didelphys americanus).
Loeding, Erin – Metamorphosis in axolotl salamanders.
Long, Wes – Clearing and staining small vertebrates and vertebrate embryos.
Mescall, Kimberly – Osteology preparation, skeletal repair, laser scanning specimens, and cataloging of vertebrate specimens.
Muzzupappa, Giuseppe – Clearing and staining small vertebrates and vertebrate embryos.
Neeley, Emily – Clearing and staining small vertebrates and vertebrate embryos.
Perry, Nadia – Clearing and staining small vertebrates and vertebrate embryos.
Voss, Amanda – Clearing and staining small vertebrates and vertebrate embryos.
Worstell, Shannon – Clearing and staining small vertebrates and vertebrate embryos.
Graduate Student Research — 2003 to Present
Junkerman, Jamie – Anatomical study of archosaurian tibia, fibula, and mesotarsal joints: evolutionary implications for locomotion. (2004)
Jamie completed a master’s thesis under my direction studying crus shape and evolution in archosaurs, and its implications for inferring foot movements in fossil archosaurs such as dinosaurs. She attended Palmer chiropractic school and is now a licensed chiropractor.
Livingston, Victoria – Forelimb versus hindlimb differentiation in Alligator mississippiensis. (2007)
Vickie worked on understanding how the proportions of American alligator embryos change with increasing size. Archosauria is a collective term for the evolutionary clade consisting of crocodilians, dinosaurs, and birds with crocodilians being the most basal group. Several fossil members of the clade, such as dinosaurs, became bipedal, changing the function of their forelimb entirely and placing a complete locomotor emphasis on their hind limbs. But how was a bipedal stance initially achieved in dinosaurs, and was it influenced by pre-existing anatomical specializations and/or changes during growth? To test whether there is something about archosaur anatomy that pre-adapts them for bipedalism, Vickie charted changes in the limb proportions during growth of a living archosaur (Alligator mississippiensis) that retains the most primitive (and therefore originally inherited) features of dinosaurs. She was the lead author on a paper, along with Dr. Bonnan, Jen Sandrik, and colleagues recently published in the Anatomical Record on alligator limb growth.
Masters, Simon – Allometric growth of the humerus in Allosaurus: functional morphology or phylogeny? (2007)
Simon completed a Master’s Thesis under my direction, studying humerus scaling in a very common Late Jurassic theropod (predatory) dinosaur called Allosaurus. Predatory dinosaur forelimbs were fairly small for their body size and we don’t know precisely what they were doing with them. Simon’s research shed some light on changes in forelimb use as Allosaurus grew from a small juvenile to an adult nearly 30 feet long. Simon is currently employed as the Crew Supervisor for Intermountain Paleo-Consulting in Vernal, Utah. Simon was a co-author with Dr. Bonnan and Dr. James Farlow on a paper on sexing alligators (and its implications for fossil archosaurs) using femoral shape.
Morhardt, Ashley – Functional implications of the texture and morphology of the premaxilla, maxilla, and dentary bones in archosaurs. (2009)
Ashley worked with me exploring what the texture and morphology of the anterior jaw bones in archosaurs can tell us (if anything) about the overlying soft tissues, and she expanded her research to implications involving dinosaurs. She collected data from the Field Museum of Natural History in Chicago and at the Carnegie Museum of Natural History in Pittsburgh. Ashley presented her research in an oral presetnation at the Society of Vertebrate Paleontology meeting in Bristol, England, in September 2009. In her research, she found a correlation between the number of neurovascular canals in the jaw bones (regions that allow blood vessels and nerves to reach the soft tissues around the mouth) and the presence of lips, beaks, and cheeks. She defended her thesis and graduated in summer 2009. She was accepted into the Larry Witmer program of functional morphology for her Ph.D. research at the University of Ohio beginning in Fall 2010.
Nishiwaki, Takahiko – The effect of epiphyseal cartilage loss in the appendicular skeleton of galliform and ratite birds. (2009)
Taka had been working in my lab originally as an undergraduate independent study project, and elaborated that project into his Masters Thesis. Modern birds are descendants of dinosaurs called saurischian dinosaurs. Saurischian dinosaurs include two major lineages with bipedal members: the predatory theropods and the herbivorous sauropodomorphs. Taka examined the limbs of modern birds to infer how the loss epiphyseal cartilage may effect our interpretation of saurischian dinosaur locomotion. For his project, Takal examined epiphyseal cartilage loss in the long bones of domestic chickens (Gallus domesticus), ostrich chicks (Struthio camelus), and an ontogenetic series of helmeted guinea fowl (Numida meleagris). His data, along with that of Jen Sandrik, formed the basis of two peer-reviewed presentations (one invited) at the Society of Vertebrate Paleontology meetings, and a peer-reviewed paper in submission to the Anatomical Record. Taka was recently accepted into a Ph.D. program for paleontology in his home country of Japan.
Parks, Hillary – Influence of the first cervical vertebra (atlas) morphology on posture in extant and extinct primates (co-advisor, Dr. Jessica White, Sociology/Anthropology).
Hillary worked with Dr. White and I on an honors research project as an undergraduate to study the morphological link between bipedalism and the shape of the first cervical vertebra (the atlas) in humans and other primates. Because the atlas holds up and orients the head, the shape of this vertebra should have morphological signals that show us how a primate’s skull was oriented in relation to its body. After collecting data at the Field Museum of Natural History in Chicago, and at the Smithsonian in Washington, D.C., she found that a combination of phylogenetic, postural, and locomotor pressures effect the shape of the atlas in primates. Her research with us as a graduate student led her to the Natural History museum in Paris, France, and she expanded her data set to include some extinct primates. She defended her thesis in Spring 2012 and is currently working at the Burpee Museum of Natural History as part of their educational staff.
Sandrik, Jennifer – The effect of epiphyseal cartilage loss in the appendicular skeleton of Alligator mississippiensis.
Jennifer’s thesis focused on understanding the effect of epiphyseal cartilage loss in the appendicular skeleton of American alligators on their long bone dimensions. Understanding dinosaur locomotion is very difficult, and requires knowledge of the cartilage at either end of the limb to properly understand how the limbs move, but this is missing in fossils. It is unknown if the absence of the cartilage significantly affects the dimensions of the underlying calcified cartilage/bone, and consequently it not known if the motion of the limb can be reliably measured in the absence of cartilage in fossil archosaurs. Dinosaurs are archosaurs, with their living relatives being birds and crocodilians. Therefore, comparing what happens to the dimensions and shape of the limb in crocodilians and birds when the cartilage is removed might offer a general idea on how much cartilage was lost in dinosaur fossils. Her study tested the hypothesis that a significant difference in Alligator mississippiensis limb joint dimensions occurs when the epiphyseal (joint) cartilage is removed. Her results support this hypothesis, but she also found that a suprising amount of shape data is preserved after cartilage removal. Jen has published with Dr. Bonnan on alligator limb growth, and her data, along with that from Taka Nishiwaki, formed the basis of two presentations and a peer-reviewed paper in submission to the Anatomical Record.
Tuttle, Kristy – Geometric morphometric analysis of long bone allometry in Euarchontoglire mammals and its relationship to arboreality. (2009)
Kristy worked with me exploring the allometric changes in long bones of the Euarchontoglire mammals (rodents, rabbits, primates, tree shrews, dermopterans) and their potential relationship to body mass and arboreal habits. She collected a large data set of humerus and femur shape data from the Field Museum of Natural HIstory, Chicago for her thesis, which she completed and defended summer 2009. She and I are currently preparing a paper on her thesis for peer-review.