BI2CV1 Week 4 Lecture 8 - The Movement of Vertebrates PDF

The Movement of Vertebrates Emily Willoughby (2022) BI2CV1: Comparative Vertebrate Biology Lecture 8 Dr Jacob Gardner [email protected] Biomechanics Study...

The Movement of Vertebrates Emily Willoughby (2022) BI2CV1: Comparative Vertebrate Biology Lecture 8 Dr Jacob Gardner [email protected] Biomechanics Study of animal movement “The mechanics of life” How animals navigate and adapt to their surroundings Biomechanics of extinct animals Insights into forms not found in present day Understand physical limits of animals Functional innovations (e.g., terrestrial movement, flight) Quetzalcoatlus (Pterosauria), Mark Witton Patagotitan (Sauropodomorpha), AMNH Wood mouse Elephant Skeletal adaptations to size Small animals do not scale-up proportionally Thinner bones Crouched posture Wood mouse Thicker, robust bones Straight, column-like posture Elephant  Posture Sprawling was ancestral to tetrapods Early tetrapod trackway, Valentia Island (Devonian) Early tetrapod Seymouria (Permian)  Posture Erect postures require special adaptations Open hip socket in dinosaurs  Quadrupedalism Movement on all four limbs Most tetrapods (ancestral) Offers stability Forward centre-of-mass Early tetrapod Seymouria (Permian)  Bipedalism Movement on two hind-limbs Obligate bipedalism in birds and humans Obligate bipeds have erect postures Ostrich Obligate bipedalism was ancestral to dinosaurs Silesauridae, close relatives of dinosaurs  Bipedalism Movement on two hind-limbs Obligate bipedalism enabled new innovations Flight in dinosaurs (birds) Increased manual dexterity, tool use in humans  Bipedalism Movement on two hind-limbs Occasional bipedalism in other mammals and lepidosaurs (lizards) Gibbon Kangaroos also stand tripodally (three limbs) Red kangaroo Basilisk lizard  NotablePostural Exceptions enigma Art by Mark Witton Spinosaurus (theropod dinosaur) Late Cretaceous (~95 Ma) Egypt and Morocco Baryonyx Other theropods can’t pronate wrists to support hands No hand fossils for Spinosaurus  Speed Record running speeds from living animals Measure stride length Formulate relationships using statistical analysis Dr Robert McNeill Alexander, CBE FRS (1934-2016) Professor of Zoology at the University of Leeds Fellow of the Royal Society (1987) Legendary biomechanicist Applied biomechanical insights from living species to dinosaurs Alexander demonstrating dinosaur size  Alexander’s dinosaur speed calculator Alexander (1976), Nature Predicted running speeds based on stride length and body size u = 0.25 * g0.5 * SL1.67 * h-1.17 u: speed (meters/sec) g: acceleration due to gravity (~9.8 m/s) SL: stride length (meters) h: hip height (meters)  How fast can dinosaurs run? Many small dinosaurs could run fast (>35 km/hr) Large theropods like T. rex were slow (