2026 - Congratulations to Dr. Alec Wilken!
We are so excited to announce Dr. Wilken's successful defense of his thesis, entitled "The Load Paths in the Jaws of Extant Mammals and Fossil Mammaliaforms and Their Significance for Mammal Jaw and Ear Evolution". We wish him luck as he moves on to his new job at the University of Missouri!
2025 - New paper out of the Ross and Zhe-Xi Luo labs!
Congratulations to Alec Wilken and Chelsie Snipes for publishing their new paper, "Biomechanics of the mandibular middle ear of the cynodont Thrinaxodon and the evolution of mammal hearing", along with Dr. Ross and frequent collaborator Zhe-Xi Luo! This paper uses finite element analysis to show that the 250-million-year-old synapsid Thrinaxodon already possessed tympanic hearing similar to modern mammals, relying primarily on a soft-tissue eardrum for airborne sound detection. The results indicate that the functional shift toward a mammalian middle ear—detached from the jaw and specialized for sensitive hearing—occurred very early in mammalian evolutionary history. This paper was covered in UChicago's Biological Sciences Division newsletter- see the coverage here! [DOI] [Article]
2025 - Congratulations to Dr. Kaleb Sellers on his new position!
Congratulations to Kaleb Sellers, former Ross Lab postdoctoral scholar, for his new position in the Oral Biology department at the University of Illinois: Chicago, where he is now a Clinical Assistant Professor! We are thrilled to continue to have Kaleb nearby, and hope to continue spending time with him and collaborating on projects.
2025 - Kaleb Sellers, Alec Wilken, and colleagues publish a new paper in Journal of Anatomy
Congratulations to Dr. Kaleb Sellers, Alec Wilken, and their colleagues at the University of Missouri on the publication of their new paper, "Quadrate orientation and joint reaction force underwent correlated evolution during suchian evolution", in the Journal of Anatomy! Using 3D biomechanical modeling of fossils and living crocodylians, the authors show that the orientation of the quadrate bone in the jaw closely matches the orientation of joint reaction forces (JRF) in the sagittal plane. These findings demonstrate that quadrate anatomy evolved in coordination with JRF during suchian evolution, providing a quantitative framework for studying evolutionary changes in jaw joint biomechanics. [DOI] [Article]
2025 - Peishu Li, Ross Lab, and collaborators publish tongue base retraction paper
Congratulations to Dr. Peishu Li and his collaborators within and outside the Ross Lab (including two undergraduate students and one high schooler working with the lab) for publishing a new paper in Integrative and Comparative Biology. The paper compares and contrasts mechanisms of tongue base retraction in macaques, opossums, and dogs to investigate hypotheses of their evolutionary conservation, concluding that the the biomechanics of TBR are functionally diverse and not strictly determined by anatomical variation, allowing for evolutionary flexibility in hyolingual morphology without compromising swallowing performance. [DOI] [Article]
2025 - Dr. Yeganeh Sekhavati publishes new hominin foot paper
Congratulations to Ross Lab postdoc, Yeganeh Sekhavati, for publishing a new paper in the Journal of Human Evolution! The paper examines the evolution of foot morphology in hominins, focusing on changes essential for bipedalism. Dr. Sekhavati and colleagues analyzed 62 foot-related traits and reconstructed ancestral characteristics to trace foot evolution from the last common ancestor of Homo and Pan. The results suggest a Pan-like ancestor, with early adaptations for foot eversion and midtarsal stability preceding other stability features. Additionally, arboreal traits were found in the Paranthropus and Australopithecus clades, indicating evolutionary adaptations from an African ape-like ancestor. [DOI]
2025 - Dr. Ross publishes 2 new papers with lab collaborators
Dr. Ross has published 2 new papers in April. The first, coauthored with lab alum Dr. Amanda Smith, along with many other collaborators, finds that Homo habilis, while exhibiting australopith-like facial strain during biting, was not adapted for forceful molar processing, suggesting that dietary or food processing changes were significant in the emergence of Homo. The second, with Ross Lab alum Dr. Katie Whitlow and UChicago researcher Dr. Mark Westneat, finds that that bowfin, similar to teleost fishes, adapt their jaw movements, hyoid arch depression, and pectoral girdle motions based on prey type and suggests that the ability to modulate feeding strikes evolved early in actinopterygian fishes and may be an ancestral trait for jawed vertebrates.
2025 - Alec Wilken, Kaleb Sellers, and colleagues publish a new paper!
Congrats to Alec Wilken and Kaleb Sellers on their new publication in Proceedings of the National Academy of Sciences! The paper uses 3D muscle modeling and linkage analysis to shed light on the origin of powered cranial kinesis in avian dinosaurs. [DOI]
2024 - Congratulations, Peishu Li, PhD!
We are excited to announce Dr. Peishu Li's successful defense of his PhD dissertation, titled Evolutionary Morphology of the Mammalian Hyoid Apparatus: Form, Function and Diversity. We wish him luck in his new position as faculty at Ohio University!
2024 - Alec Wilken, Julia Schultz, Zhe-Xi Luo, and Callum Ross publish new paper on load path analysis
Members of the Ross Lab and collaborators have published a new paper in Journal of Experimental Biology. The paper describes using opossum mandible models to compare with in vivo data and calculate load paths, highlighting this method as a way to understand form-function relationships in the skeleton. [DOI]
2024 - Emily McParland, Dr. Ross, and colleagues publish a new paper on rat chewing kinematics
Emily McParland, Dr. Ross and colleagues, including lab alumni JD Laurence-Chasen and Kazutaka Takahashi, have published a new paper on the kinematics of chewing in the Wistar brown rat (Rattus norvegicus). This paper arose out of the fruitful collaboration between Dr. Ross's lab at the University of Chicago and Dr. Nicholas Gidmark's lab at Knox College. Because this species has an unfused mandibular symphysis, the kinematics are quite complex. The paper finds that due to the complexity, the rat is an unsuitable species in many cases for studying general mammalian chewing evolution or human chewing. [DOI]
2024 - Dr. Ross publishes paper on primate muscle fiber measurement with Dr. Andrea Taylor and colleagues
Dr. Ross is a coauthor on Dr. Andrea Taylor's new paper on muscle fiber measurement techniques in strepsirrhine and platyrrhine primates. Evidence from this paper suggests that different techniques produce different results, and therefore the purpose of the study should be considered when considering which technique to use. [DOI]
2023 - Alec Wilken co-authors a new paper on prokinesis in the feeding and locomotor systems of parrots
Alec Wilken is on a new paper from Michael Grantosky's Comparative Animal Motion Lab at NYIT. The paper describes how rosy-faced lovebirds use prokinesis during tripedal climbing and mandibular/maxillary adduction, i.e., biting. They report that the maxilla is primarily responsible for generating force during locomotion and the mandible is primarily responsible for generating force during jaw adduction. It suggests that these parrots can alter prokinetic function using modulation of neuromuscular control. [Article]
2023 - New paper from Ross-Hatsopoulos Lab Collaboration
Multiple regions of primate orofacial sensorimotor cortex encode bite force and gape.
This paper just out from the Ross-Hatsopoulos collaboration funded by R01 "Neuroplasticity and the role of sensorimotor cortex in control of orofacial function”. R01DE023816-01. [Article]
2023 - Ontogenetic changes in bite force and gape in tufted capuchins
Laird MF, Kanno CM, Yoakum, CB, Fogaça, MD, Taylor AB, Ross, CF, Chalk-Wilayto, J, Holmes, MA, Terhune, CE, de Oliveira, JA. (2023) Journal of Experimental Biology jeb.245972.
2023 - New paper from the Panagiotopoulou/Reid/Ross collaboration
The biomechanics of chewing and suckling in the infant: A potential mechanism for physiologic metopic suture closure.
Pranav N. Haravu, Miguel Gonzalez, Shelby L. Nathan, Callum F. Ross, Olga Panagiotopoulou, Russell R. Reid [Article]
2023 - Dysphagia Review: Biomechanical and Cortical Control of Tongue Movements During Chewing and Swallowing
Biomechanical and Cortical Control of Tongue Movements During Chewing and Swallowing
Callum F. Ross, J. D. Laurence-Chasen, Peishu Li, Courtney Orsbon & Nicholas G. Hatsopoulos
This review of biomechanical and cortical control of the tongue is just out in Dysphagia! Based in part on dissertation work by JD Laurence-Chasen, Courtney Orsbon, and Peishu Li, this is another output from the Ross/Hatsopoulos collaboration on neural control of orofacial behaviors. [DOI]
2023 - Ross-Hatsopoulos Lab paper
Robust cortical encoding of 3D tongue shape during feeding in macaques
This new paper from the long-standing Ross-Hatsopoulos Lab collaboration was based on JD Laurence-Chasen's dissertation. This is the first evidence that the brain encodes shape dynamics of a muscular soft-body. Great work, JD! [Article]
2023 - New Ross Lab paper on macaques as models for human mandibular fracture fixation
Macaca mulatta is a good model for human mandibular fixation research
This paper is a product of our collaborations with Dr. Russell Reid MD, PhD at University of Chicago, Olga Pangiotopoulou, PhD at Monash. Two Pritzker School of Medical Medicine students worked on this paper, with Pranav Haravu leading the charge. Thanks to all involved. [Article]
2023 - New Ross Lab paper on sagittal suture strain in capuchins
Thanks to Craig Byron for leading the charge on this great paper reporting in vivo bone strain from multiple sites across the sagittal suture in capuchins. These are important data on the variation in strain along the suture and across different behaviors.
Sagittal suture strain in capuchin monkeys (Sapajus and Cebus) during feeding
Craig Byron | David Reed | Jose Iriarte-Diaz | Qian Wang | David Strait | Myra F. Laird | Callum F. Ross [Article]
2023 - New Ross Lab paper
Callum signed onto an important statement about personal autonomy and self-determination in health care. Thanks to Jason organ and colleagues for getting this important statement out.
Personal Autonomy and Self-Determination are Crucial for Professionalism in Healthcare [Article]
2023 - AAA Meeting in DC
The Ross Lab was represented at American Association of Anatomy conference in Washington DC with great podium presentations by:
Alec Wilken on Using Load Path Theory to Understand the Role of Trabecular Bone in Mandibles
Kaleb Sellers on The Effects of Skull Flattening on Crocodylian Cranial Biomechanics
Felippe Prado on Biomechanics of Pierre Robin Mandibular Distraction Osteogenesis.
Callum Ross presented a poster on why 2D FEA of vertebrate mandibles is flawed, based on our recent paper by Amanda Smith et al in Journal of Royal Society Interface.
Great work by the Ross Lab Crew. [Article]
2023 - Ross Lab postdoc Kaleb Sellers wins Early Career Anatomist Publication Award
Congratulations, Kaleb! Great work.
2023 - Midwest Regional SICB
2022 - Evan Johnson-Ransom joins Ross and Sereno Labs
The Ross Lab is excited to have Evan as a colleague and team member. Evan received his Bachelor’s from DePaul University (2018) and his Master’s from Oklahoma State University (2021). He was a summer graduate fellow at the Smithsonian National Museum of Natural History (2022). He works on dinosaur skulls! Welcome, Evan!
2022 - Alec Wilken in Neuroscience Training Program!
Alec Wilken has been admitted into the Neural, Computational, and Neuromechanical Approaches to Motor Control Training Program, funded by a T32 training grant at University of Chicago. Congratulations to Alec!
2022 - Great Lakes Student Paleoconference
Ross Lab student Peishu Li joined Isaac Magallanes, Caroline Abbott, Laura Hunter, Broc Kokesh and Rachel Laker in organizing The Great Lakes Student Paleoconference, a student-lead effort to connect and share research in paleontology around the Great Lakes region. GLSP is a great place for students to gain confidence in promoting their work in a low stress setting, network among their peers, and experience world-class collections and facilities at neighboring institutions. This year, the 4th iteration of this conference took place both on the UChicago campus and at the Field Museum on Oct 21-23, 2022. Graduate students, undergraduates, and postdocs attended and presented. The meeting was a great success.
2022 - South Side Science Fair
The science festival was a great success! Peishu, Isaac Magallanes from the Luo Lab, and Alec created displays to show off inner ear and jaw evolution and presented 3-D models of teeth. The jaw display included models of fossils loaded with rubber band "muscles" that festival attendees could use to close the jaw after pulling it down.
They also brought force gages so attendees could measure the "bite force" of the jaw. They then used videos of their XROMM, FEA, and CT work to show how 21st century paleontologists tackle problems. They inspired many little therians to consider pursuing a passion in paleontology and got an invite to present these outreach tools for an event at Rush in the spring!
2022 - SICB 2023
Members of the Ross Lab/UChicago IB Program will be presenting their work at SICB 2023.
- Hannah Farrell: Cortical bone distribution in the hominoid clavicle during ontogeny
- Samantha Gartner: Elastic skull ligaments and the biomechanics of the parrotfish bite.
- Peishu Li: XROMM reveals tongue base retraction mechanism during swallowing in Didelphis virginiana.
- Alec Wilken: The effect of trabecular bone on force transfer in the jaws of mammals.
