ZOO 2090 Lecture Notes - Lecture 10: Cursorial, Thermoregulation, Concertina

• School: University of Guelph
• Department: Zoology
• Course: ZOO 2090
• Professor: Jinzhong Fu

Document Summary

Amniote tree (amniota is the most common ancestor for modern mammals and reptiles. Early amniotes evolved in the early/mid-carboniferous and show affinities with anthracosaurs. The earliest amniotes were often small (~20cm long) and had a slight but highly ossified skeleton (cid:894)(cid:862)liza(cid:396)d-like(cid:863)(cid:895) Jaws, teeth and neck are modified for improved predation. Two species hylonomus (left) and paleothyris (right) were found inside fossilized hollow tree stumps in nova scotia. Amniote key features: cleidoic egg(cid:198)means there is a shell, most defining characteristic of amniotes. Amphibian egg (right: a(cid:373)(cid:374)iote egg has , a semi-permeable shell which allows gases to pass (o2, co2) but keeps fluids inside. Here, ligaments joining shoulder neural spines to skull and neck vertebrae help support heavy head of the bison: tendons distribute the forces of muscle contractions to sites distant from the muscle itself, change in limb posture. Long necks are beneficial in humans because we have rib cages (ventilation)