Constraining Morphologies of Soft Tissues in Extinct Vertebrates Using Multibody Dynamic Simulations: A Case Study on Articular Cartilage of the Sauropod Dreadnoughtus

Rarity of soft tissue preservation, including articular cartilage, in the fossil record hinders creation biologically-realistic mechanical models. Previous studies cartilage extant taxa have documented important aspects shapes and thicknesses, but these insights remain generalized yet to see systematic implementation biomechanical modeling. Herein, we present a new method for modeling joints that allows testing hypotheses about morphology extinct taxa. Our case study examines left elbow joint sauropod dinosaur Dreadnoughtus schrani using reconstructions constrained by phylogenetic bracketing (EPB). EPB investigations alligator chicken revealed presence spherical anterior projection on distal humerus which articulates with radius during flexion. Importantly, this shape does not directly mirror underlying bone. Using multibody dynamic models created Adams™ without priori restrictions degrees freedom, simulated effects three alternative based findings differ mediolateral placement sphere its anteroposterior thickness, encompassing range possibilities condition . Bone kinematics contact area (calculated Geomagic ® ) were tracked. Additionally, modeled an turkey same methodology compared results XROMM (X-ray Reconstruction Moving Morphology) analysis limbs. Each model produced distinct generally similar supporting our methodology. Based findings, predict , presumably other archosaurs, had face end articulation radius. Though many valuable been gained existing methodologies, chose different approach focused surfaces. Moreover, applying methods within quantitative hypothesis-testing framework can advance field paleobiology relating are possible prescribed motions.