Birds still share many traits with their dinosaur ancestors, making them the best living group to reconstruct certain aspects of non-avian theropod biology. Bipedal, digitigrade locomotion and parasagittal hindlimb movement are some of those inherited traits. Living birds, however, maintain an unusually crouched hindlimb posture and locomotion powered by knee flexion, in contrast to the inferred primitive condition of non-avian theropods: more upright posture and limb movement powered by femur retraction.
Walking Like Dinosaurs: Chickens with Artificial Tails Provide Clues about Non-Avian Theropod Locomotion. Bruno Grossi, José
Ink and Posca paint pen on paper, 6”x6”.