PennsylvaniaPennsylvaniaMammalsMammals

Mr. DistasioMr. DistasioPVHSPVHS

Mammal Characteristics –

Introductory video

Mammal Characteristics• Female has milk-secreting mammary

glands. • When an animal is weaned it must

seek out food other than mother’s milk.

Most are born alive.• viviparousviviparous: internal nourishment via the placenta

• oviviparousoviviparous: eggs hatch outside

Covered with hair.

All mammals are vertebrates.

• Two occipital condyles.

• Seven (7) cervicalcervical vertebrae.

• Diaphragm separates body cavity.

Homeothermic / Endothermic

•Four (4) chambered heart

All mammals have sweat glands.

All mammals have fat producing glands.

Mammal Classification• Tooth structure

incisorsincisorsmolarsmolarscaninescaninespremolarspremolars

• Foot structure

“Flat-footed” “Walks on toes”

Gastrulation

Mammalian Evolution

• Cenozoic Era: “the age of mammals”

over 70 million years

Three major groups:

Monotremes: egg laying

Marsupials: pouched

Placental mammals

Other Important Mammal Terms

Albino BrowserHibernation Home RangeMange MastOmnivore RabiesRut CarnivoreDelayed Implantation FeralGestation HeatGrazer HerbivoreOpportunist r/K selective