Investigating jaw muscle mechanics of birds and dinosaurs with a team of peers, Ian N. Cost, Ph.D., assistant professor of biology at Albright College has published new research that explores relationships in evolution using ternary diagrams and 3D modeling.
Published in the February 2022 Journal of Experimental Biology, Cost’s “2D and 3D visualizations of archosaur jaw muscle mechanics, ontogeny and phylogeny using ternary diagrams and 3D modeling” shows examples of how 3D structures can be represented in 2D graphics.

Whle ternary diagrams are not new, using them to investigate relationships in evolution, changes muscles make when animals bite down on things, and show changes over an animal’s lifetime are new uses of the tool.
“One thing that is very interesting about this is that we can map changes in the directions that muscles are oriented in within the head over time,” says Cost. “So, we can see what changes animals like alligators (they hatch with little boxy heads and grow up to have really long flat heads) go through during their lifetime.”
Cost’s team also used ternary diagrams to compare the same muscles with alligators, Tyrannosaurus rex, and three birds. “They’re all related, so it’s really interesting to see how they evolved different muscle orientations that do similar things, like bite really hard,” says Cost.
Funded by the National Science Foundation and the University of Missouri, the project’s research team members include Ian Cost (Albright College), Kaleb Sellers (Rocky Vista University), Rachel Rozin (Florida Aquarium), Anthony Spates (Aspen Dental), Kevin Middleton (University of Missouri) and Casey Holliday (University of Missouri).