Meeting Abstract
Many lizards, birds and other vertebrates exhibit cranial kinesis or movement among skull bones. Although the skeletal anatomy of some cranial joints are understood, how these joints are built histologically and how they are loaded during feeding remains poorly understood. To determine the impact of soft, connective tissues in the skulls of kinetic vertebrates we developed a Finite Element model of Varanus exanthematicus that mimics different types of kinetic linkages including fused, synovial and ligamentous joint types. Muscle force magnitudes were calculated from physiological cross-sectional area estimates, muscle attachments were mapped and several muscle force load patterns were created using Boneload computational methods. These load cases allowed us to better elucidate the role of the protractor and pterygoideus musculature in the palate as well as the skull in general. These load cases were applied to models with different soft tissue linkages to better learn the role of soft tissues and the protractor musculature in cranial kinesis. Modeling joints as non-bony soft tissues produced deformations that more closely approximated known in vivo feeding kinematics. This concordance affirms the model’s ability to mimic feeding mechanics; therefore, the methods used to develop the varanid model can be used to test hypotheses about the functional and evolutionary variation of cranial kinesis in not only lepidosaurs but also other vertebrates.
