Lawrence M. Witmer, PhD
Professor of Anatomy
Chang Ying-Chien Professor of Paleontology
OU Presidential Research Scholar 2004-2009

Dept. of Biomedical Sciences
College of Osteopathic Medicine
Life Science Building, Rm 123
Ohio University
Athens, Ohio 45701 USA

Phone: 740 593 9489
Fax: 740 593 2400
Email: witmerL@ohio.edu

 

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Research &

Laboratory

 

Research Statement

  Research in the Witmer Lab at Ohio University proceeds along a number of directions, but the overarching theme is functional morphology of the heads of vertebrates. A major focus for years has been the reconstruction of soft tissues (e.g., muscles, blood vessels, nerves, air sinuses, skin, etc.) in dinosaurs. Thus, vertebrate paleontology and the study of dinosaur fossils is an important activity. But, since fossils tend to preserve only hard parts like bones and teeth, much of the effort in the lab is devoted to studying modern animals. As a result, the projects are very diverse ranging from studies of the nasal apparatus of Diplodocus to the brain and ear of Tyrannosaurus rex to the horns of rhinos and giraffe to the air sinuses of alligator heads to the snouts of moose, and so on. We use traditional techniques (such as dissection and vascular injection), as well as the latest high-tech imaging and 3D-visualization techniques. The details of anatomical structure are our stock and trade. These anatomical details, played out over the course of  phylogeny, record the evolution of adaptation, and their study provides a better understanding of the vertebrate head: how it works—from physiology to biomechanics—and how it evolves.
   
 

WitmerLab News!

Tobin Hieronymus has two papers published on aquatic birds in the Thewissen & Nummela volume.

• Hieronymus, T. L. 2008. Comparative anatomy and physiology of chemical senses in aquatic birds. In: Thewissen, J.G.M., and S. Nummela (eds), Sensory Evolution on the Threshold, Adaptations in Secondarily Aquatic Vertebrates. University of California Press.

• Thewissen, J. G. M., and T. L. Hieronymus. 2008. Evolutionary relationships of aquatic birds. In: Thewissen, J.G.M., and S. Nummela (eds), Sensory Evolution on the Threshold, Adaptations in Secondarily Aquatic Vertebrates. University of California Press.

(2008-01-24)

Dave Dufeau successfully passed his Comprehensive Qualifying Examinations, and has now fully advanced to PhD candidacy.   (2007-12-06)
Paper on the African sauropod dinosaur Nigersaurus published in PLoS ONE (2007-11-15)

• Sereno, P. C., J. A. Wilson, L. M. Witmer, J. A. Whitlock, A. Maga, O. Ide, and T. A. Rowe. 2007. Structural extremes in a Cretaceous dinosaur. PLoS ONE 2(11): e1230. doi:10.1371/journal.pone.0001230.

• PLoS Supplementary Information

• PLoS tabulation of media response

• NPR Morning Edition interview with Sereno & Witmer (3.6 MB MP3) (web)

• Nigersaurus main page on Project Exploration site Skull and Brain page

• Nigersaurus page on DigiMorph site

• movies generated by Witmer & Ridgely for the Nigersaurus project
• rotating skull in natural alert posture (4.6 MB) (13 MB)
• rotating skull in intermediate posture (4.4 MB) (13 MB)
• brain endocast and inner ear (roll) (2.8 MB) (32 MB)
• brain endocast and inner ear (yaw) (2.8 MB) (32 MB)
• brain endocast and inner ear (tumble) (2.6 MB) (29 MB)
• rotating maxilla with tooth battery (6 MB)
• rotating premaxilla with tooth battery (6 MB)

The abstracts of presentations at the 8th International Congress of Vertebrate Morphology (ICVM 8) in  Paris were recently published in the Journal of Morphology. WitmerLab abstracts are below. (2007-11-15)

• Hieronymus, T. L. and L. M. Witmer. 2007. Turtle beaks, bird beaks, croc beaks? Parallel evolution of rhamphothecae in Sauropsida. Journal of Morphology 268(12):1083–1084.

• Holliday, C. M. and L. M. Witmer. 2007. Cranial kinesis in dinosaurs: significance for functional inferences and evolution. Journal of Morphology 268(12):1085–1086.

• Ridgely, R. C. and L. M. Witmer. 2007. Gross Anatomical Brain Region Approximation (GABRA): a new technique for assessing brain structure in dinosaurs and other fossil archosaurs. Journal of Morphology 268(12):1124.

• Tickhill, J. and L. M. Witmer. 2007. The Virtual Pig Head: digital imaging in cephalic anatomy. Journal of Morphology 268(12):1141.

• Tsuihiji, T., M. Kearney, and O. Rieppel. 2007. Dissociation between the axial myology and osteology in the anterior precloacal region of limb-reduced squamates including snakes. Journal of Morphology 268(12):1142.

• Witmer, L. M. and R. C. Ridgely. 2007. Evolving an on-board flight computer: brain, ears, and exaptation in the evolution of birds and other theropod dinosaurs. Journal of Morphology 268(12):1150.

• Dufeau, D. L. and L. M. Witmer.  2007.  Ontogeny and phylogeny of the tympanic pneumatic system of crocodyliform archosaurs. This abstract was somehow and regrettably omitted from the Journal of Morphology abstract volume.

Taka Tsuihiji published a very important paper in the Journal of Morphology (2007-11-15):

• Tsuihiji, T. 2007. Homologies of longissimus, iliocostalis, and hypaxial muscles in the anterior presacral region of extant Diapsida. Journal of Morphology. 268:986–1020.

The WitmerLab traveled to Austin, Texas, for the annual meeting of the Society of Vertebrate Paleontology, and it was a very successful meeting. Our abstracts are below. (2007-10-23)

• Daniel, J. and L. M. Witmer. 2007. The role of soft tissues in sediment infilling and patterning: an actualistic study with ostrich heads. Journal of Vertebrate Paleontology 27(Supplement to 3):65A.

• Dufeau, D. L. and L. M. Witmer. 2007. Ontogeny and phylogeny of the tympanic pneumatic system of crocodyliform archosaurs. Journal of Vertebrate Paleontology 27(Supplement to 3):70A.

• Hieronymus, T. L. and L. M. Witmer. 2007. Skinning dinosaurs: bony correlates and patterns of cephalic skin evolution in Archosauria. Journal of Vertebrate Paleontology 27(Supplement to 3):89A.

• Holliday, C. M. and L. M. Witmer. 2007. The epipterygoid of crocodyliforms and its significance in the evolution of the orbitotemporal region of eusuchians. Journal of Vertebrate Paleontology 27(Supplement to 3):90A.

• Tsuihiji, T., M. Watabe, L. M. Witmer, T. Tsubamoto, K. Tsogtbaatar. 2007. A juvenile skeleton of Tarbosaurus with a nearly complete skull and its implications for ontogenetic change in tyrannosaurids. Journal of Vertebrate Paleontology 27(Supplement to 3):160A.

Justin Tickhill successfully defended his masters thesis—"The Virtual Pig Head: digital imaging of cephalic anatomy"—on 02 August 2007. Justin's thesis took the unique form of a website. Justin will remain here in Athens for the next year or so before striking out for his next endeavor. (2007-08-29)

• Visit the Virtual Pig Head website!

• At the 8th International Congress of Vertebrate Morphology in Paris, France, 16–21 July, 2007, it was announced that Witmer was elected President-Elect of the International Society of Vertebrate Morphology. He will remain President-Elect and a member of the Executive Committee until the next ICVM (Uruguay 2010) at which point he will become President. (2007-08-03)
• Skull of Majungasaurus paper published as a Journal of Vertebrate Paleontology Memoir: Sampson & Witmer

Click the link to view a lay abstract, images, and other links and to download the paper (2007-06-29)

Newly available PDFs of older but often requested papers. All are fully searchable, and some have had better versions of the original illustrations inserted.

• Witmer 1999 The phylogenetic history of paranasal air sinuses. in The Paranasal Sinuses of Higher Primates. (4 MB)
• Witmer 1997 The evolution of the antorbital cavity of archosaurs... JVP Memoir 3. (24 MB)
• Witmer 1997 Craniofacial air sinus systems. in The Encyclopedia of Dinosaurs. (4 MB)
• Witmer 1995 Homology of facial structures in extant archosaurs... Journal of Morphology. (5.5 MB)
• Witmer 1995 The Extant Phylogenetic Bracket... in Functional Morphology in Vertebrate Paleontology (4 MB)
• Witmer 1987 The nature of the antorbital fossa of archosaurs... in SMTE4 Short Papers. (1.2 MB)

see Publications or CV for full citations. (2007-06-16)

• Archosaur jaw muscle homology paper published in the Journal of Morphology: Holliday & Witmer

Click the link to view a lay abstract, images, and other links and to download the paper (2007-06-10)

• Rhino horn growth paper published in the Journal of Morphology: Hieronymus, Witmer, & Ridgely

Click the link to view a lay abstract, images, and other links and to download the paper (2006-10-31)

• Flamingo vasculature paper published in the Anatomical Record: Holliday, Ridgely, Balanoff, & Witmer

Click the link to view a lay abstract, images, movies, and other links and to download the paper (2006-10-30)

• Casey Holliday finishes doctorate and takes tenure-track job at the Joan C. Edwards School of Medicine at Marshall University

Perspectives (Nov. 2001) published a nice overview of the philosophy, goals, approaches, and history of research in the Witmer lab. 

 

Funding for projects in the Witmer Lab derive primarily from grants to Witmer from the National Science Foundation (NSF) with important support from Ohio University and the OU College of Osteopathic Medicine

 

   
  note: Research in the Witmer lab does not involve experimentation on live animals.  Specimens of modern animals used in research are salvage specimens, obtained legally from commercial or governmental sources.
  Ohio University
College of Osteopathic Medicine
Irvine Hall, Athens, Ohio 45701
740-593-2530 740-597-2778 fax
 

Last updated: 01/24/2008