Ryan Ridgely - Research

Research publications and abstracts:

Tsuihiji, T., M. Watabe, K. Togtbaatar, T. Tsubamoto, R. Barsbold, S. Suzuki, A. H. Lee, R. C. Ridgely, Y. Kawahara, and L. M. Witmer. 2011. Cranial osteology of a juvenile specimen of Tarbosaurus bataar from the Nemegt Formation (Upper Cretaceous) of Bugin Tsav, Mongolia. Journal of Vertebrate Paleontology 31:497–517.

Zelenitsky, D. K., F. Therrien, R. C. Ridgely, A. R. McGee, and L. M. Witmer. 2011. Evolution of olfaction in non-avian theropod dinosaurs and birds. Proceedings of the Royal Society B.

Witmer, L. M. and R. C. Ridgely. 2010. The Cleveland tyrannosaur skull (Nanotyrannus or Tyrannosaurus): new findings based on CT scanning, with special reference to the braincase. Kirtlandia 57:61–81.

Ridgely, R.C., Witmer, L.M., James, H., Olson, S., Iwaniuk, A. 2010. Whatever fits the bill: Novel digital techniques for reconstructing skull and eyeball anatomy in the extinct Hawaiian duck, Talpanas lippa. Journal of Vertebrate Paleontology. (abstract)

Snively, E., Witmer, L., Ridgely, R., Wroe, S., Ryan, M. 2010. Impact and scythe-like jaw function in large Cretaceous theropods: Majungasaurus, Tyrannosaurus, and Giganotosaurus compared. Journal of Vertebrate Paleontology. (abstract)

Witmer, L., Ridgely, R., James, H., Olson, S., Iwaniuk, A. 2010. Neuroanatomy, skull morphology, and behavioral implications for the remarkable, recently extinct "platypus-duck" Talpanas lippa (Aves: Anseriformes) from Kauai, Hawaii. Journal of Vertebrate Paleontology. (abstract)

Holliday CM, Ridgely RC, Sedlmayr JC, Witmer LM. 2010. Cartilaginous Epiphyses in Extant Archosaurs and Their Implications for Reconstructing Limb Function in Dinosaurs. PLoS ONE 5(9): e13120. doi:10.1371/journal.pone.0013120

O’Connor, P.M., Sertich J.W., Stevens, N.J., Roberts E.M., Gottfried M.D., Hieronymus T.L., Jinnah Z.A., Ridgely, R.C., Ngasala, S.E. and J. Temba. 2010. The evolution of mammal-like crocodyliforms in the Cretaceous Period of Gondwana. Nature 466:748-751

Witmer, L.M. and R.C. Ridgely. 2009. New insights into the brain, braincase, and ear region of tyrannosaurs, with implications for sensory organization and behavior. Anatomical Record 292:1266–1296.

Evans, D., L. M. Witmer, and R. C. Ridgely. 2009. Endocranial anatomy of lambeosaurine dinosaurs: a sensorineural perspective on cranial crest function. Anatomical Record 292:1315–1337.

Witmer, L.M. and R.C. Ridgely. 2008. The Paranasal Air Sinuses of Predatory and Armored Dinosaurs (Archosauria: Theropoda & Ankylosauria) and their Contribution to Cephalic Structures. The Anatomical Record 291:1362–1388.

Witmer, L.M. and R.C. Ridgely. 2008. Structure of the brain cavity and inner ear of the centrosaurine ceratopsid Pachyrhinosaurus based on CT scanning and 3D visualization. Pp. 117–144 in P. J. Currie (ed.), A New Horned Dinosaur From an Upper Cretaceous Bone Bed in Alberta. National Research Council Research Press, Ottawa.

L.M. Witmer, R.C. Ridgely, D Dufeau, and M. Semones. 2008. Using CT to peer into the past: 3D visualization of the brain and ear regions of birds, crocodiles, and nonavian dinosaurs. in H. Endo and R. Frey. Anatomical Imaging: Towards a New Morphology. (Book Chapter)

R.C. Ridgely and L.M. Witmer. 2008. Gross Anatomical Brain Region Approximation: A new technique for assessing brain structure in dinosaurs and other fossil archosaurs. Journal of Vertebrate Paleontology. (abstract)

Witmer, L.M. and R.C. Ridgely. 2008. Air spaces within the heads of dinosaurs and their contribution to cephalic structure. Journal of Vertebrate Paleontology. (abstract)

Smith, D., D. Dufeau, R. Sanders, R.C. Ridgely and L.M. Witmer. 2008. The cranial endocast of Eutretauranosuchus delfsi (Crocodyliformes, Goniopholididae) and its relationship to other cephalic spaces. Journal of Vertebrate Paleontology. (abstract)

Evans, D., L.M. Witmer, R.C. Ridgely and J Horner. 2008. Endocranial anatomy of lambeosaurine dinosaurs: Implications for cranial crest function and evolution. Journal of Vertebrate Paleontology. (abstract)

R.C. Ridgely and L.M. Witmer. 2007. Gross anatomical brain region approximation (GABRA): A new technique for assessing brain structure in dinosaurs and other fossil archosaurs. ICVM-8/Journal of Morphology. (abstract)

Holliday, C. M., R. C. Ridgely, L. M. Witmer and A. Balanoff. 2006. Cephalic Vasular Anatomy in Flamingos (Phoenicpoterus ruber) Based on Novel Vascular Injection and Computed Tomographic Imaging Analyses. The Anatomical Record.

Ridgely, R.C. and L.M. Witmer. 2006. Dead on Arrival: Optimizing CT data Acquisition of fossils using modern hospital CT scanners. Journal of Vertebrate Paleontology (abstract).

O'Connor, P., Stevens, N., Gottfried, M., Ridgely, R., Roberts, E. 2006. New archosaur discoveries from the Cretaceous Red Sandstone Group of the Rukwa Rift Basin, southwestern Tanzania. Journal of Vertebrate Paleontology (abstract).

Hieronymus, T.L., Witmer, L.M., and R.C. Ridgely. 2006. Structure of White Rhinoceros (Ceratotherium simum) Horn Investigated by X-ray Computed Tomography and Histology With Implications for Growth and External Form. Journal of Morphology.

Ridgely, R.C. and L.M. Witmer. 2006. Braincase morphology in tyrannosaurs using computed tomography and 3D visualization, with special reference to the cerebral endocast and ear region. 2006 Annual meeting of the Society and Comparative Biology (abstract).

Witmer, L.M. and R.C. Ridgely. 2005. Tyrannosaur brain and ear structure: Ontogeny and implications for sensory function and behavior. Journal of Vertebrate Paleontology (abstract).

Ridgely, R.C. and L.M. Witmer. 2004. New applications of CT scanning and 3D modeling for dinosaur visualization. Journal of Vertebrate Paleontology (abstract).

Witmer, L.M., Ridgely, R.C., and S. Sampson. 2004. The ear region, cerebral endocast, and cephalic sinuses of the abelisaurid theropod dinosaur Majungatholus. Journal of Vertebrate Paleontology (abstract).

Witmer, L.M., Ridgely , R.C., Mayle, H., and D. Adams. 2004. The best of both worlds: integrating CT and MR in a study of pig knees. RT Image August 9, 2004

Ridgely, R.C. and L.M. Witmer, 2004. Beyond imaging: using 3D datasets in comparative morphology. 7th International Congress of Vertebrate Morphology. Journal of Morphology (abstract).

Witmer, L.M., Chatterjee, S., Franzosa, J., Rowe, T., Ridgely, R. 2004. Neuroanatomy and vestibular apparatus of pterosaurs: Implications for flight, posture, and behavior. 2004 Annual Meeting of the Society of Integrative and Comparative Biology (abstract).

Witmer, L. M., C. M. Holliday, P. M. O’Connor, A. B. Clifford, R. C. Ridgely, and T. L. Hieronymus. 2003. Anatomical study of wild and zoo animals using medical imaging and diverse anatomical methods. Annual Meeting for the American Zoo and Aquarium Association (abstract).

Bennett, G. E., III, D. J. Main, and R.C. Ridgely. 2003 Preliminary report of new microvertebrate localities in the latest Maastrichtian Hell Creek formation near Brownie Butte, Garfield County, Montana. Geological Society of America Abstracts with Programs. 35(1) (abstract).

Witmer, L., Holliday, C., O’Connor, P., Clifford, A., Sedlmayr, J., Ridgely, R., Beatty, B., and T. Hieronymus. 2002. New approaches for the study of skeletal and soft-tissue anatomy in modern and extinct vertebrates. OU-COM Research Day, 2002 (abstract).

Holliday, C. M., R. C. Ridgely, J. C. Sedlmayr, and Witmer, L. M. 2002 The articular cartilage of extant archosaur limb bones: implications for dinosaur functional morphology and allometry. Annual Meeting of the Society of Integrative and Comparative Biology, Anaheim, California. American Zoologist. 41(6) (abstract).

Holliday, C. M., R. C. Ridgely, J. C. Sedlmayr, and Witmer, L. M. 2001. The articular cartilage of extant archosaur limb bones: implications for dinosaur functional morphology and allometry. Journal of Vertebrate Paleontology. 21 (3:Suppl.) (abstract).

Holliday, C. M., J. C. Sedlmayr, R. C. Ridgely, and L. M Witmer. 2001. The articular cartilage of extant archosaur long bones: implications for dinosaur functional morphology and allometry. Journal of Morphology. 248(3):241-242 (abstract).

Funding:

Witmer, L.M., Hurlburt, G.R., and R. C. Ridgely. Brain evolution in archosaurs: new implications for scaling, function, and the evolution of the modern conditions in birds and crocodilians. National Science Foundation, 2005-2008

Other publications: