BISC 316 Lecture Notes - Lecture 13: Shoulder Girdle, Occipital Condyle, Synapsid

• School: Simon Fraser University
• Department: Biological Sciences
• Course: BISC 316
• Professor: T M

Document Summary

Evolved from lineage synapsida: first fossils are reptiles, synapsid contains ancestor mammal like reptile and mammals, mammal like reptile syanodont 18-3, pelacasaurs, therapsids. Morphological changes from therapsid to mammal: simplification of skeletal system fewer bones in pectoral girdle and skull. Hair present in some stage of all mammals. Endothermic think fast, move fast: first radiation. Triassic to cretaceous: stem mammals, docodonths, trichondontia, monotramatic. First monotreme fossil in early cretaceous deposists: marsupial + true placentals, separate fom other lineages since beginning of jurassic, jaw articulation. Quadroarticular = therapsid: middle ear bones. Scapes, incus and mallus is in ear: mammals have two occipital condyle, secondary pallet chew and breathe at same time, separation from nasal and oral. Range of motion from atlas and axis articulating with occipital condyle cavity. Premaxilla, maxilla, bones: single cusped teeth, pleurodont, behind skull bones are different, legs are closer to body, changes under body rotation in elbows and knees, change position, anatomy .