BIO 1130 Lecture Notes - Lecture 2: Shoulder Girdle, American Cheetah, Digitigrade

• School: University of Ottawa
• Department: Biology
• Course: BIO 1130
• Professor: Jon Houseman

Document Summary

Retractable claws: 25myr: all big cats have retractable claws. Protects nails from being worn out too quickly. Oldest species of cats we have now is about 25 mill years old. Cheetah have semi-retractable claws: 5. 5myr: only a part of its claw will go back into the foot, more blunt, gives more grip when running/turning direction, unique to the cheetah (evolved in cheetah) Hindlegs of a cheetah: the result of 440 mill years of evolution. Adaptation of vertebrates in cheetahs: locomotion organs (fins or limbs) Adaptations of terrestrial tetrapods in cheetahs: pectoral girdle (scapula) detached from skull. Pectoral girdle is fused from the cranium in fish (fish"s environment never caused it to evolve a neck) As animals moved to the land, they evolved to remove the fusion of the pectoral girdle to the cranium (allowed formation of neck: pelvic girdle (pelvis) fused to the vertebral column. Adaptations of mammals in cheetahs: rotation of the knees and elbows under the body (support/speed)