BIOL 111 Lecture 22: Mammals

• School: McGill University
• Department: Biology (Sci)
• Course: BIOL 111
• Professor: Rudiger Krahe

Document Summary

~ 5,000 species: sweat glands, insulation, camouflage, sensory & defence, mammary glands, milk production. Skull morphology differences in amniotes: skull types of amniotes, anapsids (turtles, synapsids (incl. Therapsids & mammals: euryapsids (extinct marine reptiles, diapsids (incl. dinosaurs & birds, key difference between skulls is presence, size & number of temporal fenestrae leads to holes that provide more surface area for muscle attachment. ~225 mya (triassic: early mammals were small, arboreal, shrew-like insectivores, nocturnal, hadrocodium wui. ~195 mya (jurassic: found in china, size: 32mm, 2g, significantly larger brain for its size, has middle ear bones derived from jaw. 1. 5 mya to 11,000 yrs (pleistocene: contemporary with humans, mammoths and giant ground sloths. Mammalia other features: endothermic, advanced nervous system. Internal fertilization: unlike reptiles and fish, mammals also show heterodonty, different teeth specialized for different tasks, specialization in teeth among species reflects varied diets. Sexual dimorphism: sexes appear different, size, color, morphology.