The Mammals
endothermy -- mammals are homeotherm
hair -- even “naked” mammals such as whales have sensitive bristles on their snouts
claws and fingernails are made of keratin as hairs
hooves are special keratin pads on the toes
- in contrast: horns = bone core attached to the skull, covered with skin and hair
mammary glands in females in all mammals
head on flexible neck with typically 7 cervical vertebrae
heterodont teeth, i.e. differently shaped teeth
heart 4-chambered; red blood cells lack nucleus
diaphragm separates thorax and abdomen
placenta -- except in the most primitive mammals