Introduction to Mammals
Endotherms Hair or Fur Feed Young with Milk
Phylogeny
• Separated into three groups
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Prototheria (before gestation) – egg laying mammals
Metatheria (middle gestation) – pouched mammals
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Eutheria (true gestation) – live birth from uterus
Milk Produced in mammary glands • May have been sweat glands • Feed young, increase success
Types of teeth
• Incisors – cutting • Canines – can be enlarged, piercing • Carnassal – shearing, remove meat from bones • Molars - grinding
Cardiovascular System
• Body temperature is internally regulated (endothermic) • Heart is 4-chambered • High metabolism • Heart rate – depends on size of animal (smaller = faster rate)
Excretory System
• Urinary bladder – need more water per day • Advanced kidneys – filter more blood
Reproductive System
Dioecious Highly variable in shape Placental mammals Nonplacental mammals
Digestive System
• Length differs based on diet
–Predators short –Herbivores very long –Omnivores medium length