INTEGBI N33 Lecture Notes - Lecture 13: Crurotarsi, Euparkeria, Neoteny
31 Mar 2018
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Crurotarsal ankle - from need of strong and stable ankle. Less flexible than ancestral condition and has diagonal plane of flexion; allows for semi-erect posture. Femur attached to acetabulum at an angle. Allows for different gaits of posture and faster locomotion when needed. Have s-shaped femur (femur at an angle and curved) and solid. Crocodiles have sprawling and semi-erect (high walk) gait acetabulum for supporting weight. More than 1 mode of locomotion; way of moving based on speed (eg. speed, foot pattern, sprawling, semi-erect) Primitive crurotarsi small animal that likely resembled ancestral archosaurs. Have a little bit of dermal armour and is likely a facultative biped (could walk on two feet if wanted; long tail keeps from being top heavy) Strong jaws to bite and spin underwater. Use broad tails to propel through water. Modern crocodiles secondarily evolved sprawling posture because of the aquatic lifestyle; but newborn crocs have more erect posture " example of neoteny.
