Patrick O'Connor, Ph.D.

Professor of Anatomy and Neuroscience
Ohio University


Current Lab Members

Joe Groenke imageJoseph Groenke (B.S./B.A. University of Michigan)
Laboratory Technician/Coordinator (2017 - present)
Department of Biomedical Sciences, Heritage College of Osteopathic Medicine.

Joe focuses on the technical development of paleontological and neontological data through digital and mechanical preparation, as well as its replication through molding, casting, digital reconstructions, and prototyping. In the O’Connor lab he works principally with fossil material from the Late Cretaceous of Madagascar and Tanzania. He played a logistical coordinating role in several field seasons in Madagascar between 2005 and 2012, and has been a crew member of other work in eastern Africa and Western North America.

Selected Publications:
Krause, D. W., S. Hoffmann, J. R. Wible, E. C. Kirk, J. A. Schultz, W. v. Koenigswald, J. R. Groenke, J. B. Rossie, P. M. O’Connor, E. R. Seiffert, E. R. Dumont, W. L. Holloway, R. R. Rogers, L. J. Rahantarisoa, A. D. Kemp, and H. Andriamialison. First cranial remains of gondwanatherian mammal reveal remarkable mosaicism. Nature 515:512-517 (2014).

O’Connor, P. M., D. W. Krause, N. J. Stevens, J. R. Groenke, R. D. E. MacPhee, and D. Kalthoff. A new mammal from the Upper Cretaceous (Turonian - Campanian) Galula Formation, southwestern Tanzania. Acta Paleontologica Polonica. Accepted January 2019.


Sam Gutherz Image Sam Gutherz (B.S. Georgetown University)
Current Ph.D. Student (2016 - present)
Graduate Program in Biological Sciences
Ohio Center for Ecology and Evolutionary Studies

Sam is interested in the interactions between pulmonary tissue and the skeleton in birds. By studying the development of postcranial pneumaticity in living birds, he hopes to address questions regarding the evolution of the respiratory system in a range of archosaurs. His other research interest include studying ontogenetic changes in non-avian theropod dinosaurs. Past research has included neurobiological research in rat models and field work in North Dakota and Montana.

Selected Publications:
Gutherz, S.
and P. M. O'Connor. 2019. Postcranial skeletal pneumaticity in Cuclidae. Submitted for the 2019 annual conference of the Society of Integrative and Comparative Biology.

Eric Lund imageEric Lund (B.S./M.Sc. University of Utah)
Current Ph.D. Student (2014 - present)
Graduate Program in Biological Sciences and Geological Sciences
Individual Interdisciplinary Program, Ohio Center for Ecology and Evolutionary Studies
Lab Coordinator (2011-2016), Department of Biomedical Sciences


Eric is interested in the paleobiology and functional morphology of ceratopsian (horned) dinosaurs and faunal evolution in the Western Interior Basin during the Cretaceous Period. He received his MS degree from the University of Utah in 2010. He has had the opportunity to conduct paleontological field work in Utah, Wyoming, and around the world including Mexico, Tanzania and Madagascar. Eric first moved to Ohio University in late 2011 to work as a laboratory coordinator with the O'Connor lab. He later matriculated as a PhD student in the IIP, focusing his research around ceratopsid evolutionary morphology and functional anatomy. Eric is currently completing his Ph.D. while also serving as the Fossil Conservation Laboratory Manager at the North Carolina Museum of Natural Sciences working with Dr. Lindsay Zanno.

Selected Publications:
Lund, E. K.
, P. M. O’Connor, M. A. Loewen, and Z. A. Jinnah. A New Centrosaurine Ceratopsid, Machairoceratops cronusi gen et sp. nov., from the upper sand member of the Wahweap Formation (Middle Campanian), Southern Utah. PLoS ONE 11(5):e0154403 (2016) doi:10.1371/journal.pone.0154403. PDF available upon request

Sampson, S. D., E. K. Lund, M. A. Loewen, A. A. Farke, and K. E. Clayton. 2013. A remarkable short snouted horned dinosaur from the Late Cretaceous (late Campanian) of southern Laramidia. Proceedings of the Royal Society B: Biological Sciences 280 (1766):20131186.


Former Students & Lab Associates

Ryan Felice imageRyan Felice
Former PhD Student, Completed Ph.D. 2015
Graduate Program in Biological Sciences (2009 - 2015)
Ohio Center for Ecology and Evolutionary Studies

Current Position: Lecturer in Anatomical Sciences, Department of Cell and Developmental Biology, University College London

Ryan's Research Website

Ryan is interested in the paleobiology, evolution, and functional morphology. His dissertation was entitled: Evolution and Integration of Avian Caudal Skeletal Morphology. Other research efforts included field work in Wyoming, Utah and Tanzania and a study of synapsid locomotion. After completing his PhD in 2015, Ryan moved to the UK to complete a postdoctoral research fellowship in the lab group of Dr. Anjali Goswami at UC London/Natural History Museum-London. Ryan and Pat currently collaborate on analyses of cranial shape dispartiy and evolution in birds and crocodyliforms.

Selected Publications from PhD:

Felice, R.N., and P. M. O'Connor. 2016 Function drives caudal skeletal variation in sexually dimorphic passeriforms. Journal of Avian Biology: 47:371-377. doi: 10.1111/jav.00801

Felice, R.N. 2014 (early view). Coevolution of Caudal Skeleton and Tail Feathers in Birds. Journal of Morphology. doi: 10.1002/jmor.20321

Felice, R. N., and P. M. O’Connor. 2014. Ecology and caudal skeleton morphology in birds: The convergent evolution of pygostyle shape in underwater foraging taxa. PLoS One 9(2): e89737. doi:10.1371/journal.pone.0089737.


Eric Gorscak Image Eric Gorscak
Former Ph.D. Student, Completed Ph.D. 2016
Graduate Program in Biological Sciences (2010-2016)
Ohio Center for Ecology and Evolutionary Studies

Current Position: Assistant Professor in Anatomical Sciences, Midwestern University-Chicago College of Osteopathic Medicine

Eric's Research Website


Research Interests:
Eric is interested phylogenetics, biogeography, and the evolution of African dinosaurs and other vertebrates during the Cretaceous Period. His dissertation was entitled: Descriptive and Comparative Morphology of African Titanosaurian Sauropods: New Information on the Evolution of Cretaceous African Continental Faunas. After completing his PhD in 2016, Eric undertook a postdoctoral research fellowship at the Field Museum of Natural History (Chicago) with Dr. Peter Makovicky. A portion of his research falls under the larger Rukwa Rift Basin Project of southwestern Tanzania. During his PhD, Eric participating in number field expeditions, including those associated with ongoing field research in Tanzania, Antarctica, Utah, and Madagascar.

Selected Publications from PhD:

Gorscak, E., P. M. O’Connor, N. J. Stevens, and E. M. Roberts. 2017. The second titanosaurian (Dinosauria: Sauropoda) from the middle Cretaceous Galula Formation, southwestern Tanzania with remarks on African titanosaurian diversity. Journal of Vertebrate Paleontology 37: available upon request

Gorscak, E. and P. M. O’Connor. 2016. Time-calibrated models support congruency between Cretaceous rifting and titanosaurian evolutionary history. Biology Letters 12:20151047 PDF available upon request

Gorscak, E., P. M. O'Connor, N. J. Stevens, and E. M. Roberts. 2014. The basal titanosaurian Rukwatitan bisepultus (Dinosauria, Sauropoda) from the middle Cretaceous Galula Formation, Rukwa Rift Basin, southwestern Tanzania. Journal of Vertebrate Paleontology 34:1133–1154. PDF available upon request


Waymon Holloway Waymon Lewis Holloway
Former Ph.D. Student, Completed Ph.D. 2018
Graduate Program in Biological Sciences (2013 - 2018)
Ohio Center for Ecology and Evolutionary Studies

Current Position: Postdoctoral Researcher, Department of Anatomical Sciences, Stony Brook School of Medicine, Stony Brook, NY, USA (2018 - present).

Waymon is interested in the functional anatomy of the head and sensory system evolution of archosaurs. His dissertation was entitled: Comparative Cranial Ecomorphology and Functional Morphology of Semiaquatic Faunivorous Crurotarsans. His past research has included invertebrate and microfloral surveys and a digital phytosaur endocast reconstruction, the latter as part of his MS project at Marshall University.

Selected Publication from PhD:
Holloway, W. L., K. M. Claeson, H. M. Sallam, J. J. W. Sertich, and P. M. O’Connor. 2017. A new species of the neopterygian fish Enchodus from the Duwi Formation, Campanian, Late Cretaceous, Western Desert, central Egyptr. Acta Palaeontologica Polonica 62:603-611. doi: PDF available upon request

Holloway, W.L., K.M. Claeson, and F.R. O’Keefe. 2013. A virtual phytosaur endocast and its implications for sensory system evolution in archosaurs. Journal of Vertebrate Paleontology 33:848-857. PDF available upon request


Liva Ratsimbaholison image Nirina (Liva) Ratsimbaholison
Former Ph.D. Student, Completed Ph.D. 2016
Biological Anthropology and Paleontology, University of Antananarivo, Madagascar
Affiliated Student, Ohio Center for Ecology and Evolutionary Studies

Liva completed a Ph.D. in 2016 entitled: Ontogenetic Trends in the Craniomandibular Skeleton of Abelisauridae. He has conducted field research along with the MBP field teams since 2005. Since completing his Ph.D. he has returned to Madagascar, completed a research visit in India, and is continuing to work on publishing dissertation chapters with P. O'Connor and T. Hieronymus.

DEA [Masters Degree] in Paleontology, Université d’Antananarivo, Madagascar. Project Title: Ontogenie Craniofaciale de Majungasaurus crenatissimus (Theropode: Abelisauridae) du Cretace Superieur de Berivotra-Mahajanga. Thesis Defended: April, 2008.

Project Title: Ontogenetic variability of cranio-mandidular system in Majungasaurus crenatissimus.

Selected Publications from PhD:
Ratsimbaholison. N. O.
, R. N. Felice, and P. M. O’Connor. 2016. Ontogenetic changes in the craniomandibular skeleton of Majungasaurus crenatissimus from the Late Cretaceous of Madagascar. Acta Palaeontologica Polonica 61:281-292 (2016). PDF available upon request


Kerin Claeson ImageKerin M. Claeson, Ph.D.
Postdoctoral Researcher April 2010-June 2012
Department of Biomedical Sciences, Anatomy Instructor
Ohio Center for Ecology and Evolutionary Studies
Current Position: Philadelphia College of Osteopathic Medicine

Kerin’s research combines the disciplines of paleontology, comparative anatomy, and development to formulate and test phylogenetic hypotheses of interrelationships of several groups of fishes, and occasionally other vertebrates. She makes extensive use of worldwide museum collections but has also had the opportunity to conduct field work in Argentina, Pennsylvania, Texas, and Wyoming. She received her PhD in Geological Sciences from The University of Texas at Austin in 2010 and her Masters in Organismic and Evolutionary Biology from the University of Massachusetts at Amherst in 2005. Kerin started a position as an Assistant Professor of Anatomy at the Philadelphia College of Osteopathic Medicine in July 2012.

Selected recent publications
Claeson, K. M.
, J. T. Eastman, and R. MacPhee. 2012. Definitive specimens of Merlucciidae (Gadiformes) from the Eocene of Isla Marambio (Seymour Island), Antarctic Peninsula. Antarctic Science 24:467-472..

Aschliman, N.C., Claeson, K. M., and J. D. McEachran. 2012. Phylogeny of Batoidea. In: Biology of Sharks and Their Relatives 2nd Edition, J. C. Carrier, J. A. Musick, and M. R. Heithaus (eds.), CRC Press. pp. 57-96.


Erin L. (Rasmusson) Simons
Ph.D. Department of Biological Sciences (2004 - 2009)
Ohio Center for Ecology and Evolutionary Studies

Project Title: Evolution of the avian wing skeleton: Integrating whole bone morphology, cross-sectional geometry, histology, and mechanical testing for evaluating the relationship between form and function in the forelimb of birds.

Current Position: Associate Professor of Anatomy, Midwestern University (Glendale, AZ).

Selected Publications from PhD:
Simons, E. L. R. and P. M. O’Connor. Bone laminarity in the avian forelimb skeleton and its relationship to flight mode: Testing Functional Interpretations. Anatomical Record 295:386-396 (2012).

Simons, E. L. R., T. L. Hieronymus, and P. M. O’Connor. Cross sectional geometry of the forelimb skeleton and flight mode in pelecaniform birds. J Morphology 272(8):958-971 (2011).


Sarah Gutzwiller
Honors Tutorial College Senior Thesis (2009)
Department of Biological Sciences

Thesis Title: Postcranial skeletal pneumaticity, bone structure, and foraging style in two clades of neognath birds.

Current Position: Ph.D. student in the Department of Evolution, Ecology, and Organismal Biology at The Ohio State University. Current advisor: John Hunter, Ph.D.

Publication from Senior Thesis:
S. Gutzwiller,
A. Su, and P. M. O’Connor. Postcranial pneumaticity and bone structure in two clades of neognath birds. Anatomical Record 296:867-876 (2013)