Meeting Abstract
Cranial biomechanics are an understudied aspect of avian functional morphology despite numerous studies conducted on model organisms such as Darwin’s Finches and birds of prey. One of the most biomechanically understudied but widespread groups of birds are the parrots (Aves: Psittaciformes). Globally distributed and representing numerous ecological niches, parrots represent a diverse array of feeding biomechanics despite similar cranial morphology. This similar morphology is optimized to dissipate stresses and mobilize the craniofacial hinge to increase the gape size available to parrots. We biomechanically tested finite element models (FEM) of 7 genera of parrots (Strigops, Nestor, Melopsittacus, Psittacus, Deroptyus, Brotogeris) and an outgroup species (Falco) that exhibit disparate diets including: folivory, omnivory, frugivory and granivory, and carnivory. Our FEMs were constructed with individual palatal elements linked by joint materials, biomechanically relevant constraints, and forces estimated using BoneLoad workflow for individual muscles. Posterior bilateral bite points were used to produce maximum bite force and approximate parrot feeding behavior. We used the FEM results as benchmarks to analyze the environment of the extinct parrot Conuropsis carolinensis, which had a known diet consisting of mostly seeds and fruits. As the only parrot native to North America, we hypothesized that Conuropsis would exhibit a stress profile similar to those of Deroptyus and Brotogeris; South American fruit and seed eating parrots. We found that Conuropsis is morphologically similar to other parrots and biomechanically similar to other granivorous parrots, regardless of phylogenetic proximity. Our innovative modelling methods show that extant and extinct biomechanical environments can be accurately recreated, described, and compared.
