Dinosaurs & Cavemen Open House 2020

Posted on January 28, 2020 by Casey

 

This February 28-29th, 2020, join us for a Special Dinosaurs & Cavemen Science Expo. Previously, we’ve brought our labs to you at Rock Bridge High School and elsewhere. This year, come visit us in our Integrative Anatomy labs in the University of Missouri School of Medicine for a special open house and speaker. We’re opening our doors so you can learn how discoveries are made and meet the scientists behind them. Come learn about Hominid fossils, Crocodile and Dinosaur skulls, 3D Imaging and Printing, Microscopy, Anatomy Education and more!

 Come hear our special guest speaker, Boonville, MO native, Professor David Polly (Indiana University) who is giving TWO talks about evolution, climate change, and giant snakes. DID I SAY GIANT SNAKES??? Talk #1 on Friday is geared towards a hard science audience and will discuss how animals modify their body shapes to cope with ecology and climate. Talk #2 on Saturday is a public talk that takes us into the world of giant snakes and reptiles in the greenhouse climate of the Paleocene , 60 million years ago.

 

Schedule

Friday February 28th:

12-3pm Open House: 3rd floor Anatomy wing of Medical Sciences Building  (see directions below)

3:30-4:30pm, Science Seminar: David Polly: Functional traits, environments, and clades: at the interface of climate, ecology, and evolution. Where? School of Medicine PCCLC Room LC230 (see directions below)

SMS Titanoboa

Titanoboa considers swallowing a local crocodile on the banks of a river during the Paleocene of what is now Colombia, South America. Art by Jason Bourque.

 

Saturday, February 29th:

10:30-11:30, Saturday Morning Science Public Talk: 

David Polly: Hip-Deep in giant snakes: Titanoboa and temperature in the Paleocene. Where?: School of Medicine PCCLC Room LC230 (see directions below)

 

12-3pm Open House: 3rd floor Anatomy wing of Medical Sciences Building  (see directions below)

 

 

About the Speaker

Polly

David Polly, Indiana University

David Polly is a vertebrate paleontologist and the Robert R. Shrock Chair in Earth and Atmospheric Sciences at Indiana University.  His research is on the evolution of mammals, responses of vertebrate communities to largescale environmental change, and processes of morphological evolution.  He grew up in central Missouri, received a BA from the University of Texas, Austin (1987) and a PhD from University of California, Berkeley (1993), which was followed by a postdoc at University of Michigan (1994-1996) and faculty position at the School of Biological Sciences and Bart’s and the London School of Medicine and Dentistry at Queen Mary, University of London (1997-2006).  He recently served as president of the Society of Vertebrate Paleontology.

DirectionsMap

Free weekend parking is available in University Avenue Parking Structure, Virginia Avenue Parking Structure and the Virginia Avenue Garage Surface Lot. 

Talks will be held in the PCCLC (Patient Care Centered Learning Center), the new School of Medicine building overlooking the west end of Stankowski field. You will be able to enter the building through its West Entrance off of Tiger Avenue,  from campus through the School of Medicine Atrium near the Health Sciences Library or through University Hospital (though its less recommended). Room LC230 is the large lecture hall on the North end of the building; You can’t miss it. Location: PCCLC is here

Like regular Saturday Morning Sciences, light refreshments will be available starting 10am Saturday Feb 29th. 

The Integrative Anatomy Open House will be on the 3rd floor of the Medical Sciences Building, which is attached to the PCCLC and Health Sciences Library. Follow the dinosaur footprints and signs up the stairs or elevators to the 3rd floor and onto the Anatomy Wing. Our labs will be open for you to get guided tours and discussions with resident scientists. There will be loads of interesting and fun activities and demonstrations for kids and adults.  See you there! 

Contact:

Casey M. Holliday, PhD: hollidayca@missouri.edu; 573-884-6599

Thanks to our hosts and sponsors the Department of Pathology and Anatomical Sciences, the Integrative Anatomy Program, The University of Missouri School of Medicine, Saturday Morning Science, and the National Science Foundation.

 

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2018 Midwest Regional SICB Meeting

Posted on September 10, 2018 by Casey

Hey!! The 2018 Midwest Regional SICB Meeting is happening here, Saturday October 6, 2018. Come check it out!! http://anatomy.missouri.edu/SICB/SICB MIZZOU LOGO_Draft_tony

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NSF Summer Research Experience for STEM Teachers in Comparative Biomechanics, Paleontology and Evolution

Posted on March 2, 2016 by Casey

Inside_Dinosaurs_RET 2016Research Experience for STEM Teacher position is available at the University of Missouri Integrative Anatomy program for the summer of 2016. The teacher will design and conduct studies that explore the anatomy and biomechanics of birds, dinosaurs, and crocodilians as part of the NSF-sponsored Inside Dinosaurs program to better understand the evolution of vertebrate feeding biomechanics and the origins of avian cranial kinesis. The teacher will work under the supervision of Drs. Casey Holliday and Kevin Middleton, alongside postdocs, graduate students and undergraduates. We are particularly interested in teachers interested in helping translate research in biomechanics, vertebrate paleontology and bone biology into grade 6-12 classroom activities and/or web modules that foster the understanding of physics, biology and evolution in line with NGSS. The teacher will be involved in all components of their project as well as a variety of related projects being conducted in the department.

Candidates should be available for May 31-July 30th or thereabouts. We will provide parking and a stipend of $4000 for ~20/hrs a week for 8 weeks of the summer.

The ideal candidate should be interested in developing and promoting new curricular materials for local and online STEM students based on their experiences in the program. The position is renewable for 2 additional summers and resources are available to aid in dissemination of findings and materials at national conferences as well as the development of teacher workshops to test and evaluate the new curricular materials. Individuals should be creative, industrious, detail-oriented and comfortable working as part of a team. Experience in biology, anatomy, physiology, physics, mathematics, or geology is required. Experience with field, collections, or laboratory work in these areas is a plus but not necessary.

Application deadline: April 10, 2016

Applications should include: Contact information for two professional references, CV/resume and a one page statement that describes your interest in the position, goals and any previous research-teaching experiences.

Applications should be sent to Dr. Casey Holliday at hollidayca@missouri.edu with ‘2016 RET application” in the subject line. Please feel free to contact me if you have any questions.

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NSF Summer Research Experience in Comparative Biomechanics, Paleontology and Evolution

Posted on January 15, 2016 by Casey

Inside_Dinosaurs REU 2016Research Experience for Undergraduate positions are available at the University of Missouri Integrative Anatomy program for the summer of 2016. THE REU students will design and conduct studies that explore the anatomy and biomechanics of birds, dinosaurs, and reptiles as part of the NSF-sponsored Inside Dinosaurs program to better understand the evolution of vertebrate feeding biomechanics and the origins of avian cranial kinesis. The REU students will work with a team of researchers under the supervision of Drs. Casey Holliday and Kevin Middleton. We are particularly interested in students interested in conducting projects in comparative biomechanics, vertebrate paleontology and skeletal tissue biology. The REU students will be involved in all components of their project as well as a variety of related projects being conducted by other researchers.

The REU students will join a broader summer internship program through the University of Missouri. In addition to a full-time faculty-mentored research experience, students engage in educational programming including professional development, topical small group seminars, 14 evening lectures given by University of Missouri faculty and staff, and social activities. All students participating in the Summer Program develop a research abstract and create a poster to present at the Summer Forum.

Candidates must be available for May 31-July 30th. We will provide transportation fees, room and board at University of Missouri dormitory and dining facilities, transportation fees, support for their research and a $3500 stipend.

The ideal candidate should be interested in pursuing a career in anatomy, paleontology or biomechanics, creative, industrious, detail-oriented and comfortable working as part of a research team. Experience with field, collections, or laboratory work in these areas is a plus but not necessary. Background or at least coursework in biology, anatomy, physiology, mathematics, or geology is required. To be eligible you must not have received your degree before January 2016.

Application deadline: March 1, 2016

Applications should include: copy of unofficial transcripts, contact information for two academic references, CV/resume and an one page statement that describes your interest in the REU position, academic goals and any previous research experiences.

Applications should be sent to Dr. Casey Holliday at hollidayca@missouri.edu with ‘2016 REU application” in the subject line. Please feel free to contact me if you have any questions.

 

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Postdoctoral Fellow Position Open: Evolution of Dinosaur Jaw Musculature and the Origins of Avian Cranial Kinesis.

Posted on March 2, 2015 by Casey

POSTDOCTORAL FELLOW POSITION Spring 2015

Position Details:

Project title: Evolution of Dinosaur Jaw Musculature and the Origins of Avian Cranial Kinesis. Postdoctoral Fellow, University of Missouri, Columbia, MO.

The Department of Pathology and Anatomical Sciences at the University of Missouri School of Medicine invites applications for a postdoctoral research associate. The position is for one year and is renewable up to 3 years. The successful applicant will work under the supervision of Drs. Casey M. Holliday and Kevin M. Middleton on a National Science Foundation-funded program in 3D Cranial Biomechanics and Morphometrics. The position is 80% Research and 20% Outreach (allocation is negotiable) and offers a competitive salary plus benefits. Review of applications will begin March 1, 2015 and remain open until filled with an anticipated start date of August 1, 2015.

Responsibilities:

1) The candidate will work directly with PIs Holliday and Middleton to develop and conduct analyses of cranial biomechanics and morphometrics of fossil and extant dinosaur species. They will also interact with coPIs Julian Davis and Lawrence Witmer on occasion.

2) The candidate will help develop 3D anatomical and biomechanical visualizations and mobilize these data to appropriate online databases and outreach locations.

3) The candidate will present findings in collaboration with project leaders and associated students. The candidate will develop and participate in the Inside Dinosaurs education and outreach program at University of Missouri. Funds for research expenses and travel are available.

Qualifications

By the start date, all elements of the PhD, including the dissertation, must be completed and the degree conferred in biological, earth sciences, engineering or similar field, with an emphasis on vertebrate biomechanics and paleobiology.

Additional qualifications include demonstrated experience in one or more of the following: 3D computational biology, Morphometric analysis, and/or 3D anatomical visualization such as experience working with CT image data and with 3D model rendering software (Amira, Maya), MATLAB, and R; demonstrated experience managing personnel and leading research projects; and demonstrated ability to publish in English-language peer-reviewed journals.

Prefernce will be given to individuals with interests in morphology-based research and whose interests complement those of current faculty in the Integrative Anatomy group (http://anatomy.missouri.edu) will be given priority. The Integrative Anatomy Group provides a collegial environment with substantial opportunities for intellectual creativity and diverse research.

Application Materials

To apply please submit (1) cover letter including contact information for three references; (2) curriculum vitae; and (3) a research statement including previous experience and future plans

University of Missouri web site is hrs.missouri.edu/find-a-job/academic/.  At the top of the webpage, select ‘prospective employees’ and search for ‘pathology’ to reach the link for the position.  The Job ID number is 15786.

Benefit Eligibility

This position is eligible for University benefits. The University offers a comprehensive benefits package, including medical, dental and vision plans, retirement, and educational fee discounts.  For additional information on University benefits, please visit the Faculty & Staff Benefits website at http://www.umsystem.edu/totalrewards/benefits.

Equal Employment Opportunity

The University of Missouri is an equal access, equal opportunity, affirmative action employer that is fully committed to achieving a diverse faculty and staff. The university will recruit and employ qualified personnel and will provide equal opportunities during employment without regard to race, color, religion, national origin, sex, sexual orientation, age, status as a protected veteran or status as a qualified person with a disability. For more information, call the Associate Vice Chancellor of Human Resource Services/Affirmative Action officer at 573-882-4256. To request ADA accommodations, please call the Director of Accessibility & ADA Education at 573-882-5835.

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Looking for a Postdoc Fall 2015

Posted on December 23, 2014 by Casey

As part of our NSF grant on Avian Cranial Kinesis, we’ll be looking to fill a 3yr Postdoc at University of Missouri, Summer/Fall 2015.

The official ad won’t come out for a while, but any interested parties should contact me (Casey Holliday). I’ll be at SICB and EB/AAA this Spring to chat.

In general, we’re looking for someone with skills and interests to help develop 3D computational modeling, musculoskeletal biomechanics, morphometrics and 3D viz associated with testing patterns of skull form & function across phylogenies. Experience and vision with Strand7, Maya, Matlab, R, Avizo, and/or similar software packages is highly favorable. Some background in reptile and avian cranial anatomy is very helpful but not required.

Feel free to distribute widely.

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We’re Back

Posted on December 22, 2014 by Casey

Poor neglected blog page! The lab is bustling!

1620531_10204546420236421_3261568282529368030_nSome big news: We’ve been funded by NSF to pursue a project on the biomechanical and evolutionary patterns underlying the origins of avian cranial kinesis. We’ll be developing a series of 3D computational, morphometric, and visualization tools to better understand the relationships between muscle forces, joint shape, loading, feeding function and cranial evolution along the line to birds. We’re collaborating with Kevin Middleton (Mizzou), Larry Witmer (Ohio University) and Julian Davis (University of Southern Indiana).

We’ve got 5 presentations at SICB 2015 in lovely West Palm Beach: sicb2_01

The Functional and Evolutionary Significance of the Crocodyliform Pterygomandibular Joint HOLLIDAY, CM*; SELLERS , KC; VICKARYOUS, MK; ROSS, CF; PORRO, LB; WITMER, LM; DAVIS, JL; University of Missouri; University of Missouri; University of Guelph; University of Chicago; Bristol University; Ohio University; University of Southern Indiana

More than one way to be a giant: convergence and disparity in saurischian dinosaur hip joints during body size evolution TSAI, H.P.*; MIDDLETON, K.M.; HOLLIDAY, C.M.; University of Missouri; University of Missouri; University of Missouri

Material properties of the mandibular symphysis in Alligator mississippiensis SMOLINSKY, AN*; MIDDLETON, KM; PFEIFFER, F; HOLLIDAY, CM; University of Missouri; University of Missouri; University of Missouri; University of Missouri

Ontogeny and complexity of the mandibular symphysis of crocodylians. JACOBY, MJ*; GANT, CA; SELLERS, KC; HOLLIDAY, CM;  University of Missouri-Columbia

Estimates of Three-Dimensional Cranial Joint Forces in the American Alligator SELLERS, KC*; DAVIS, JL; MONGALO, M; JACOBY, MJ; HOLLIDAY, CM; Univ. of Missouri; Univ. of Southern Indiana; Univ. of Missouri; Univ. of Missouri; Univ. of Missouri

 

Stay tuned for updates on a search for a postdoc and more.

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ICVM-10 Symposium on Reptile Skeletal Biology

Posted on July 5, 2013 by Casey

ICVMInterested in the latest research on reptile development, biomechanics and evolution? Come to our symposium at the International Congress of Vertebrate Morphology in Barcelona next Tuesday (July 9, 2013). If not, be sure to catch some of the other outstanding talks held in the neighboring rooms. 

Symposium 7: Reptile Skeletal Biology: Investigations Into Tissue Morphology, Development, and Evolution

Organizers: Casey Holliday, University of Missouri; Matthew Vickaryous, University of Guelph

Reptiles are one of the most ancient and morphologically diverse radiations of tetrapods.  An important feature underpinning this diversity is the skeleton. While the reptilian skeleton has a long history of appreciation by palaeontologists, morphologists and ecologists, it is now emerging as an important model for many developmental and biomedical biologists.  Furthermore, the adoption of various cutting edge approaches in molecular, imaging, and experimental techniques is leading to major revisions and re-interpretations of several longstanding ideas.  This symposium will focus on exploring some of the most intriguing and fundamental questions in evolutionary developmental biology from a uniquely reptilian perspective.  Our participants will bring forward important advancements in the study of the origin and evolution of body plans, morphogenesis and regeneration, and physiology and functional morphology . The goal of our assembled international panel (including participants from Japan, Germany, UK, France, Canada and the US) is to provide a productive and collaborative forum to share, critique and exchange approaches, techniques and species-specific expertise.  Building on the recent publication of the Anolis genome and recent funding to complete the Alligator genome, reptilian biology is undergoing an unparalleled renaissance and our symposium will highlight the latest research using turtles, lepidosaurs, crocodylians, and their fossil ancestors.  ICVM-10 presents an exceptional opportunity to highlight this next generation of reptilian skeletal biology, and its ever growing potential for the broader study of development, evolution, and functional morphology.

09:30

S-036 SKELETAL REGENERATION FOLLOWING TAIL LOSS IN LIZARDS

Vickaryous, Matt; Coates, Helen; Delorme, Steph University of Guelph, Guelph, Canada

10:00

S-037 SQUAMATE VERTEBRAL HISTOLOGY AND MICROANATOMY -DEVELOPMENT AND EVOLUTION

Houssaye, Alexandra Steinmann Institut für Geologie, Paläontologie und Mineralogie, Universität Bonn, Bonn, Germany

10:30

S-038 COMPARATIVE SKULL MECHANICS OF THE LIZARDS TUPINAMBIS MERIANAE AND VARANUS ORNATUS

Gröning, Flora (1); Jones, Marc (2); Curtis, Neil (1); O’higgins, Paul (3); Evans, Susan (2); Fagan, Michael (1) (1) University of Hull, Hull, United Kingdom; (2) University College London, London, United Kingdom; (3) University of York, York, United Kingdom

11:00

S-039 A COMPARISON OF TURTLE AND CHICKEN ONTOGENY REVEALS THE BASIS FOR DIVERGENT HARD PALATE MORPHOLOGY

Richman, Joy; Abramyan, John; Leung, KelvinLife Sciences Centre, University of British Columbia, Canada

12:00

S-040 HOW DID ENAMEL MATRIX PROTEINS EVOLVE IN REPTILE TEETH AND ARE THEY PRESENT IN OSTEODERMS?

Sire, Jean-Yves (1); Gasse, Barbara (1); Silvent, Jérémie (1); Delgado, Sidney (1); Belheouane, Meriem (1); De Buffrénil, Vivian (2) (1) Université Pierre et Marie Curie, Paris, France; (2) Muséum national d’Histoire naturelle, Paris, France

12:30

S-041 DEVELOPMENTAL PLAN OF THE AMNIOTE SHOULDER GIRDLE AND ITS EVOLUTIONARY DIVERSITY

Nagashima, Hiroshi (1); Hirasawa, Tatsuya (2); Sugahara, Fumiaki (2); Takechi, Masaki (3); Sato, Noboru (1); Kuratani, Shigeru (2) (1) Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan; (2) RIKEN Center for Developmental Biology, Kobe, Japan; (3) Iwate Medical University, Yahaba-cho, Japan

14:30

S-042 MORPHOLOGY AND FUNCTION OF THE REPTILE MANDIBULAR SYMPHYSIS

Holliday, Casey (1); Hieronymus, Tobin (2); Nesbitt, Sterling (3); Vickaryous, Matthew (4) (1) University of Missouri, Columbia, United States; (2) Northeastern Ohio Medical University, Kent, United States; (3) Field Museum of Natural History, Chicago, United States; (4) University of Guelph, Guelph, Canada

15:00

S-043 DEVELOPMENT AND EVOLUTION OF MESOPODIALIZATION IN THE ICHTHYOSAURIAN LIMB SKELETON

Maxwell, Erin (1); Scheyer, TorstenM. (1); Fowler, Donald (2) (1) Universität Zürich, Paläontologisches Institut und Museum, Switzerland; (2) McGill University, Department of Biology, Canada

15:30

S-044 FRONTIERS IN THE EVOLUTION AND DEVELOPMENT OF THE REPTILIAN SKULL

Bhullar, Bhart-Anjan (1); Marugan-Lobon, Jesus (2); Racimo, Fernando (3); Bever, Gabe (4); Rowe, Timothy (5); Norell, Mark (6); Abzhanov, Arhat (1) (1) Harvard University, Cambridge, United States; (2) University of Madrid, Madrid, Spain; (3) University of California, Berkeley, United States; (4) New York College of Osteopathic Medicine, Old Westbury, United States; (5) The University of Texas at Austin, Austin, United States; (6) American Museum of Natural History, New York, United States

16:00

S-045 CONSERVATION OF PRIMAXIAL REGIONALIZATION IN THE EVOLUTION OF THE SNAKE BODY FORM INDICATES HOMOPLASY IN HOX GENE FUNCTION

Head, Jason (1); Polly, P.David (2) (1) University of Nebraska-Lincoln, Lincoln, United States; (2) Indiana University, Bloomington, United States

17:00

S-046 IN VIVO CRANIAL BONE STRAINS DURING FEEDING IN THE LIZARDS TUPINAMBIS AND UROMASTYX

Porro, Laura (1); Ross, Callum (2); Herrel, Anthony (3); Evans, Susan (4); Fagan, Michael (5); O’Higgins, Paul (6) (1) University of Bristol, Bristol, United Kingdom; (2) University of Chicago, Chicago, United States; (3) CNRS/Muséum National d’Histoire Naturelle, Paris, France; (4) University College London, London, United Kingdom; (5) University of Hull, Hull, United Kingdom; (6) University of York, York, United Kingdom

 17:30

S-047 ARCHOSAUROMORPH BONE HISTOLOGY REVEALS EARLY EVOLUTION OF ELEVATED GROWTH AND METABOLIC RATES

Werning, Sarah (1); Irmis, Randall (2); Nesbitt, Sterling (3); Smith, Nathan (4); Turner, Alan (5); Padian, Kevin (1) (1) University of California, Berkeley,CA, United States; (2) Natural History Museum of Utah & University of Utah, Salt Lake City, UT, United States; (3) The Field Museum, Chicago, IL, United States; (4) Howard University, Washington, DC, United States; (5) Stony Brook University, Stony Brook, NY, United States

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It’s a Veggie-raptor, Lex! Veggi-raptor!

Posted on May 30, 2013 by Ally McEntire

A discussion by Henry Tsai

Most dinosaur fans would agree that theropods are among the best characterized of dinosaurs. From agile speedsters like Velociraptor to lumbering powerhouses like Tyrannosaurus, these bipedal beasts appear to the public as ideal killing machines, with jaws full of sharp teeth and the legwork to keep up with their prey.

However, recent studies of maniraptorans, the theropod group that included both dromaeosaurs like Velociraptor and modern birds, have revealed a variety of odd theropods that seem to have abandoned the predatory way of life. Therizinosaurs, a group of pot-bellied, long-necked theropods, possessed leaf-shaped teeth and slightly curved claws. Since none of these features appear useful for predation, popular hypotheses suggest ground sloth-like herbivory for these animals.

Oviraptors add to the puzzle with sharp, recurved claws at the end of powerful forelimbs and robustly built, yet toothless, beaks. This mishmash of seeming carnivorous and herbivorous traits has led to hypotheses of oviraptor diets ranging from leaves, fruits, shellfish, nuts, and even the eggs of other dinosaurs.

Finally, troodonts, the closest relatives of the obviously carnivorous dromaeosaurs, appear to have had teeth more suitable for dicing plants than for ripping meat. These lines of evidence suggest herbivory either evolved multiple times independently; or that herbivory was primitive to the entire Maniraptora, with the carnivorous dromaeosaurs as the odd-‘saurs out. Future studies on bite mechanics and tooth wear will certainly be necessary for uncovering more about the behavior and ecology of these mysterious plant-eating “raptors.”

Figure. Feeding strategy of various maniraptorans. A) The herbivorous therizinosaur Nothronychus. (picture credit: Victor Leshyk) B) The oviraptor Gigantoraptor, whose diet is still under dispute. (picture credit: Nobu Tamura) C) The carnivorous dromaeosaur Deinonychus, shown feeding on a hapless Zephyrosaurus. (picture credit: Emily Willoughby)

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Towards Finding Invisible Whiskers in Fossil Crocs

Posted on April 4, 2013 by Casey

Our paper on Alligator Trigeminal Nerve Scaling and Significance is out in Anatomical Record:

http://onlinelibrary.wiley.com/doi/10.1002/ar.22666/pdf

You can catch University of Missouri’s press release here:

https://nbsubscribe.missouri.edu/news-releases/2013/0404-new-measurement-of-crocodilian-nerves-could-lead-to-better-understanding-of-ancient-animals%E2%80%99-behavior-mu-researcher-finds/

and a snazzy video describing the research here:

http://vimeo.com/user2631252

 

This was all part of a lab rotation project by Grad Student and Life Sciences Fellow Ian George. Ian tried his hand at a Blog Post too, take it away Ian:

Croc brains and ganglia

Croc brains and ganglia

How is it that alligators are deadly accurate hunters, even on the darkest nights when their prey makes no sounds? The answer to that are dome pressure receptors, highly sensitive small black dots that pepper the sides of their face, first described by Von During (1974), which act much in the same way as whiskers do on a cat (Soares, 2002; Leitch & Catania, 2012). As soon as an unsuspecting animal disturbs the water to get a drink, these invisible whiskers detect the tiny waves they create and the alligator can strike having neither seen nor heard the animal. While we can see and count these dots in living alligators, what about in their ancestors? When did this specialized sense first appear?

Before we can determine if fossil crocodyliforms may have had these dome pressure receptors (DPRs), which are a soft tissue structure, we first need to look for some feature on the skull associated with them. Just like in humans, the face of the alligator gets its sensation from the trigeminal nerve (CNV). This nerve supplies sensation to the face of all vertebrates and evidence suggests that it is larger when there are specialized receptors present like whiskers or DPRs. This large nerve also has a large hole in the skull associated with it, the trigeminal fossa, which we can measure in living alligators and fossil crocodyliforms. Therefore this hole in the skull is an excellent place to measure the nerve that supplies the DPRs because it is present in both living alligators as wells preserved in fossils.

Alligator trigeminal nerve

Alligator trigeminal nerve

Our recent article in the Anatomical Record explores the trigeminal DPR system through an anatomical investigation of a range of different sized alligators, a few crocodiles and some fossil crocodyliforms. We CT scanned alligator heads to get volumetric measurements, dissected them to better understand the anatomy of the trigeminal nerve, and finally histologically sampled the nerve to measure how many fibers were in it. This latter part helped distinguish the relative contributions of motor versus sensory portions of the nerve. Our findings show that the trigeminal nerve scales with skull size in the alligator as well as with brain size, an important factor when measuring nervous tissue. Together with data we took from the skulls of fossilized crocodyliforms comparing the relative size of the trigeminal fossa and the maxillomandibular foramen in the skull to the overall size of the skull and brain, we can now get a good idea of relative face touch. Integrating these data with perhaps integumentary osteological correlates may then give us a good idea about DPR evolution.

This important new tool can give us new information about the habitat these extinct crocodyliforms may have lived in. If the trigeminal fossa in an extinct croc is substantially smaller than that of a living crocodylian, it may not have had DPRs or at least have had a less-sensitive face. This has bearing on the animal’s relationship with its environment and certainly can be applied to other taxa that have well encrusted trigeminal fossae.

Leitch DB, Catania KC. 2012. Structure, innervation and response properties of integumentary sensory organs in crocodilians. Journal of Experimental Biology 215:4217–4230.

Soares D. 2002. An ancient sensory organ in crocodilians. Nature 417:241–242.

von During M. 1974. The ultrastructure of the cutaneous receptors in the skin of Caiman crocodilus. Abhandlungen Rhein.-Westfal. Akad 53:123–134.

 

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