Welcome to Dr. Sheil's Lab

Observatory Park, Geauga Co.

Academic Background

Intensive Spanish Curriculum, La Universidad del Pacifico, AsunciĆ³n, Paraguay. 1994

B.Sc. Systematics and Ecology, The University of Kansas, Lawrence (Advisor: Dr. William E. Duellman). 1995

Ph.D. Ecology & Evolutionary Biology, The University of Kansas, Lawrence (Advisor: Dr. Linda Trueb). 2002
Dissertation: Skeletal Development in Turtles: Patterns of Ossification Through Ontogeny in Apalone spinifera, Chelydra serpentina, Macrochelys temminckii, and Eretmochelys imbricata (Reptilia: Chelonii).

Research: Formation & ossification of limb elements in turtles

Though sequences of formation and ossification of bony elements have been described for many taxa, controversy surrounds the formation of limb elements turtles. Three hypotheses for patterns of formation of autopodial elements have been proposed, differing primarily in the origin of Distal Carpal/Tarsal 3, the digital arch, and Centrale 4 (Figure 1).

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Patterns of formation and ossification of limb elements were described from embryos of the Red-Eared Slider, Trachemys scripta. Cleared and double-stained embryos provided the primary source of original data for this study (Figure 2),

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and these patterns of were compared to similar data for representatives of four families of turtles (Cheloniidae, Chelydridae, Emydidae, and Trionychidae), and included the Common Snapping Turtle (Chelydra serpentina), Alligator Snapping Turtle (Macrochelys temminckii), Painted Turtle (Chrysemys picta), Black-knobbed Map Turtle (Graptemys nigrinoda), Spiny Softshell Tutle (Apalone spinifera), Loggerhead Sea Turtle (Caretta caretta), and the Green Seaturtle (Chelonia mydas). Hypotheses of limb formation were compared in the context of new and published data, and shed some light on how the elements of the hands and feet of turtles arise developmentally. Data from Trachemys scripta, Chrysemys picta, and Chelydra serpentina suggest that Distal Carpal 3 forms by branching from the ulnare, whereas data from Macrochelys temminckii and Chelonia mydas suggest that Distal Carpal 3 may branch from Distal Carpal 4. Data from Graptemys nigrinoda, Apalone spinifera, and Eretmochelys imbricata did not provide evidence for the origin of Distal Carpal 3. Centrale 4 was not observed to branch from the ulnare and apparently arises by de novo condensation. Distal Carpal 4 did not branch from Centrale 4 in any species. Until the developmental origin of Distal Carpal 3 and Centrale 4 are better understood, interspecific variation in the origin of these elements remains as a primary suspect in explaining much of the observed differences. Trends of ossification in the fore- and hind limb autopodium also are summarized were identified and it seems that though the proximal bones ossify in a proximal-to-distal pattern (similar to the pattern of formation), many of the distal elements (primarily the phalanges) ossify in a distal-to-proximal pattern (opposite of their patterns of formation). The previous observations demonstrate that formation and ossification of these elements are decoupled developmental events—this is a question that I would love to have a student working on in my lab. Finally, this study afforded an excellent opportunity to assess the homology of elements in pedal Digit V, and we suggest that the hooked proximal element of Digit V in the foot should be recognized as Distal Tarsal 5. In short, we suggest that the hooked proximal element of Digit V is a distal tarsal element, not a metatarsal. Though this may seem to be a trivial point, the hooked fifth “tarsal” has been considered one of the few synapomorphies of a clade known as the Sauropsida.

Research: Development of Cranium in Turtles

Section under construction.

Research: Ecology of Turtles in Northeast Ohio

I have advised several Master's students on projects that cover aspects of the ecology of turtles in Norteast Ohio. These projects have focused on the Spotted Turtle (Clemmys guttata) and the Blanding's Turtle (Emydoidea blandingii). Though I am a morphologist, I have a passion for studying turtles, and will consider advising students on any project that involves these fine animals!

Genetic Algorith for Rule Set Prediction (GARP) is an ecological niche-modeling package that allows an investigator to correlate points of known locality data for a species with GIS variables (such as terrain aspect, maximum and minimum temperatures, precipitation, etc) to generate predictive models of suitable habitat for the species. We performed several GARP analyses to generate models of suitable habitat for the Spotted Turtle in North America and Ohio. The ultimate objective of this project was to assist the Geauga County Park District in identifying suitable habitat for this species on their land holdings. Both the national- and state-wide models identified broad ranges of over- and underprediction of suitable habitat, but the state-wide model appeared to perform much better on the scale of county-predictions.

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[This figure shows the predicive model of suitable habitat for the Clemmys guttata in Ohio. Darkest purple indicates that 10 of 10 models predicted suitable habitat in this area; yellow dots represent known localities of this species]

Areas of potential habitat for the Spotted Turtle were identified and a list of suggestions was provided to GCPD to assist in the conservation of this species on their lands.

For additional information on this project, please contact me or Lara Roketentz, MSc.

The Blandings Turtle (Emydoidea blandingii) is a SINC species in Ohio. Though this species exhibits a relatively broad geographic range over much of North America, it is a habitat specialist that in reality can be found in very few patches of remaining habitat that are broadly separated from one another. Northeast Ohio has several remaining populations of this species, and relatively little is known about their populations in this state. Jim Spetz conducted an autecological study to describe and document the seasonal diet, movement, and reproduction of this species. Adult and hatchlings were trapped, tracked with radiotelemetry, and studied for over two years.

Results of this study are still being analyzed, but it seems that this species is an opportunist in terms of diet, and feeds on a variety of seasonally-available invertebrates, ranging from crayfish, insects, and molluscs (native and introduced). Females seem to exhibit some fidelity to nesting sites, and nest success and juvenile recruitment into the population is extremely low.

Study Abroad in Costa Rica

JCU Center for Global Education and I have begun a semester-long study abroad program in Costa Rica. This program is designed for JCU students that want spend a semester in beautiful, tropical Central America while fulfilling several core credit requirements. This study abroad experience is attractive because the climate, people, food, and culture of Costa Rica are so welcoming, the biodiversity of this region of Central America is so unique!

This slide show will give you a little bit of an idea of what to expect during the biology courses.


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In one semester, students enrolled in this course will fulfill their core requirements for 2 semesters of a language (in this case Spanish), a 3 credits of Social Science, and either elective credits in biology (for biology majors) or their Division III lab science course. JCU Biology Majors will find this study abroad experience best fits their schedules during their sophomore or junior years, during the Fall Semester--just think, while your friends and classmates are freezing their toes off in Cleveland, you'll be soaking up the tropical sun, meeting cool people, and drinking fresh fruit juices! Biology Majors who want to take this during their sophomore year DEFINITELY need to talk with me about how to make this work around your course requirements for organic chemistry.

Non-biology majors will find that this program is idealy suited for completing your Division III lab science course. I can guarantee that you will get more out of this experience than just about any on-campus science class.

If you're interested in the program and want to know more, please contact me directly, or speak with the folks in the Center for Global Education.


(Interested in getting reprints? Please email csheil@jcu.edu)

2009. Faivovich J, Celio FB, Haddad CFB, Baeta D, Jungfer KH, Roldao Avarez GF, Brandao RA, Sheil CA, Barrientos LS, Barrio-Amoros CL, Cruz CAG, and Wheeler WC. The phylogenetic relationships of Phyllomedusinae (Anura, Hylidae): A group of poster frogs. Cladistics 25:1-35.

2009. Sanchez-Villagra MR, Muller H, Sheil CA, Scheyer, TM, Nagashima H, and Kuratani S. Skeletal Development in the Chinese Soft-Shelled Turtle Pelodiscus sinensis (Testudines: Trionychidae). Journal of Morphlogy 270(11):1381-1399.

2008. Sheil CA. and Portik D. Formation and ossification of limb elements in Trachemys scripta and a discussion of autopodial elements in turtles. Zoological Science 25:622-641.

2008. Jorgensen M and Sheil CA. Effects of temperature regime through Premetamorphic ontogeny on shape of the chondrocranium in the American Toad, Anaxyrus americanus. Anatomical Record 291:818-826.
2006. Tulenko, F.J., and C.A. Sheil. Formation of the chondrocranium of Trachemys scripta (Reptilia: Testudines: Emydidae) and a comparison with other described turtle taxa. Journal of Morphology 268:127–151.

2005. Sheil, C.A. Osteology and skeletal development of Macrochelys temminckii (Reptilia: Chelonii: Chelydridae). Journal of Morphology. 263:71–106.

2005. Sheil, C.A., and H. Alamillo. Osteological and skeletal development of Phyllomedusa vaillanti (Anura: Hylidae: Phyllomedusinae) and a comparison of this arboreal species with a terrestrial member of the genus. Journal of Morphology. 265:343–368.

2005. Sheil, C.A., and E. Greenbaum. Reconsideration of skeletal development of Chelydra serpentina (Reptilia: Testudinata: Chelydridae): evidence for intraspecific variation. Journal of Zoology, London. 265:235–267.

2005. Mendelson, J.R. III, B.L. Williams, C.A. Sheil, and D.G. Mulchay. Systematics of the Bufo coccifer Complex (Anura: Bufonidae) of Mesoamerica. Scientific Papers, Natural History museum, The University of Kansas. 38:1–27.

2003. Sheil, C.A. Osteology and skeletal development of Apalone spinifera (Reptilia: Chelonii: Trionychidae). Journal of Morphology 256(1):42–78.

2001. Sheil, C.A., and J.R. Mendelson III. A new species of Hemiphractus (Anura: Hylidae: Hemiphractinae), and a redescription of H. johnsoni. Herpetologica 57(2):189–202.

2001. Sheil, C.A., J.R. Mendelson III, and H.R. da Silva. Phylogenetic relationships of the species of Neotropical horned frogs, genus Hemiphractus (Anura: Hylidae: Hemiphractinae), based on evidence from morphology. Herpetologica 57(2):203–214.

2001. Sheil, C.A., and T.A. Grant. A new species of Synophis (Colubridae: Xenodontinae) from Colombia. Journal of Herpetology 35(2):204–209.

1999. Sheil, C.A. Osteology and skeletal development of Pyxicephalus adspersus (Anura: Ranidae: Raninae). Journal of Morphology 240:49–270.

1999. Seigel, R.A., and C.A. Sheil. Population viability analysis: applications for the conservation of Massasaugas. In: Proceedings, 2nd International Symposium and Workshop on the Conservation of the Eastern Massasauga Rattlesnake Sistrurus catenatus catenatus. 17–22.

1998. Himes, J.G., and C.A. Sheil. Amphiuma means (Two-toed Amphiuma). Herpetological Review 29(2):105–106.

1998. Sheil, C.A. Emmochliophis miops (Colubridae: Xenodontinae): Redescription of Synophis miops (Boulenger, 1898). Journal of Herpetology. 32(4):604–607.

1998. Seigel, R.A., C.A. Sheil, and J.S. Doody. Long-term changes in population of an endangered rattlesnake (Sistrurus catenatus) subjected to a severe flood. Biological Conservation 83(2):127–131.


Marcelo Sanchez-Villagra - Zurich, Switzerland.
Joseph Mendelson III - Zoo Atlanta, Georgia.
Hugo Alamillo - Washington State University, Pullman, WA.
Eli Greenbaum - Villanova University, Villanova, PA.

Graduate Students in the Sheilonia Lab

Current Students:
Tim Krynak (Student 010): M.S. Thesis: Roosting Ecology of Bats in Northeaster Ohio.

Jason Cotter (Student 011): M.S. Thesis: Nest Site Selection
and Temperature-Dependent Sex Determination in Chrysemys picta.

Sharon Turk (Student 012): M.S. TBA.

Past Students:
Lara Roketenetz (Student 001): M.S. Thesis: Ecological Niche Modeling in the Spotted Turtle, Clemmys guttata.

Frank Tulenko (Student 002): M.S. Thesis: Formation of the Crista Sellaris of the Red-Eared Slider, Trachemys scripta
(Reptilia: Testudinata: Emydidae). Currently a Ph.D. Candidate at Wesleyan University, under mentorship of Dr. Anne Burke.

Michael Jorgensen (Student 004): M.S. Thesis: Effects of Temperature on Phenotypica Plasticity in Anuran Larvae. Currently a Ph.D. Candidate at Ohio University under the mentorship of Dr. Steve Reilly.

James Spetz: (Student 005) M.S. Thesis: Diet, Movement, and Nesting Ecology of Blanding's Turtle, Emydoidea blandingii in Northeast Ohio. Currently working as a Naturalist for Cuyahoga County Park District.

Undergraduate Students in the Sheilonia Lab

Current Students:

Past Students:
Daniel Portik (Student 003) B.S. JCU. Honors Thesis: Formation and Ossification ofthe Autopodial Elements of Trachemys scripta. Graduated May 2007. Completed M.S. at Villanova University under mentorship of Dr. Aaron Bauer (Thesis title:XXX). Currently at the University of California, Berkeley, under the mentorship of Dr. McGuire. Dissertation Topic:

Billy DePetro (Student 004) B.Sc. JCU. Graduated May 2008.

Megan Kolupski. (Student 005) B.S. JCU. Graduated May 2007. Currently an M.S. student at the University of San Diego in the Department of Marine Science; estimated graduation May 2010.

Scott Owen (Student 008) B.S. intending to graduate May 2010. Studying formation of the chondrocranium and orbitotemporal region of Eretmochelys imbricata. Currently: TBA.

Sarah Kleinsorge (Student 009) B.S. intending to graduate May 2090. Studying formation of the chondrocranium and orbitotemporal region of Eretmochelys imbricata. Currently: TBA.

Courses Taught

BL159/160 - Principles of Biology III: Biodiversity & Evolution.
BL250/L - Comparative Anatomy of the Vertebrates
BL479 - Systematic Biology
BL405 - Scientific Illustration

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