My PhD thesis research focuses on the dynamic interaction between foot and ground, and understanding how foot movement, foot morphology, and substrate properties ultimately influence how animals move in their environment and the tracks they leave behind.

As PhD thesis work continues to progress, I have had the opportunity to collaborate on some exciting projects:

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It’s in the loop: shared sub-surface foot kinematics in birds and other dinosaurs shed light on a new dimension of fossil track diversity.

The feet of ground-dwelling birds retain many features of their dinosaurian ancestry. Experiments with living species offer insights into the formation of fossil footprints. A key aspect of the track-making process, sub-surface foot movement, is hidden by substrate opacity. Here we use X-rays to image and measure 3-D foot motions of guineafowl walking through a variety of substrates. Despite substantial step-to-step variability, the foot consistently moves in a looping pattern below the ground. Examination of Early Jurassic tracks reveals dinosaurs shared an equivalent looping response to soft substrates ~200 million years ago.

Contrast-enhanced XROMM of alligator hip soft tissue interactions

Tsai HP, Turner ML, Manafzadeh AR, Gatesy SM. (2019). Contrast-enhanced XROMM reveals in vivo soft tissue interactions in the hip of Alligator mississippiensis. Journal of Anatomy. (doi:10.1111/joa.13101)

Virtual reality (VR) visualization development for dinosaur track formation

Novotny J, Tveite J, Turner ML, Gatesy SM, Drury F, Falkingham P, Laidlaw DH. (2019). Developing Virtual Reality Visualizations for Unsteady Flow Analysis of Dinosaur Track Formation using Scientific Sketching. IEEE Transactions on Visualization and Computer Graphics.

As part of an ongoing 4+ year collaboration with Brown computer scientists/visualization/VR experts (David Laidlaw, Johannes Novotny, Joshua Tveite), a Rhode Island School of Design illustration professor (Fritz Drury), and Brown dinosaur footprint researchers (Stephen Gatesy, Peter Falkingham, and myself), we have developed new and insightful ways of visualizing complex 3D simulations of dinosaur footprint formation. Weekly immersive meetings in the YURT (virtual reality theater), along with collectively leading two courses on VR Design for Science, have made the process of developing visualizations for our datasets just as valuable as exploring the data using our the newly developed tools.

Footfall analysis from drone footage of a bottom-walking crocodile

Farlow JO, Robinson NJ, Turner ML, Black J, Gatesy SM. (2018). Footfall Pattern of a Bottom-Walking Crocodile (Crocodylus acutus). Palaios 33(9):406-413.  

James Farlow presented a fun and interesting challenge: build a bottom-walking crocodile footfall map from drone footage. Steve Gatesy and I sat down in Autodesk Maya and developed a method of tracking seashells and rocks (circles above) on the ocean floor to reconstruct drone position, then subsequently identified coordinated puffs of sand with limb movement to establish footfall locations. The resulting underwater footfall map and step length measurements are the first of it’s kind, and important for comparison to that on dry land for interpreting questionably aquatic crocodilian fossil trackways.


Prior to my thesis work at Brown, I studied pareiasaurs, an extinct clade of robust herbivorous early amniotes that thrived during the Middle to Late Permian (272-252 Ma). They were among the largest terrestrial animals to have evolved at the time, and lived alongside many of the early ‘mammal-like reptiles’. Pareiasaurs were very successful and their fossils are found distributed across Pangea in what is modern-day Europe, Asia, South America and Africa. Under the advisement of my undergraduate advisor, Christian Sidor at the University of Washington, I wrote two papers on fossil material from this fascinating clade.

Turner ML, Sidor CA. (2017). Pathology in a Permian Parareptile: Congenital Malformation of Sacral Vertebrae. Journal of Zoology. DOI:10.1111/jzo.12519.
Turner ML, Tsuji LA, Ide O, Sidor CA. (2015). The vertebrate fauna of the Upper Permian of Niger—IX. The appendicular skeleton of Bunostegos akokanensis (Parareptilia: Pareiasauria). Journal of Vertebrate Paleontology 35, e994746.