All mammals __________.

Unlike eutherians, both monotremes and marsupials

a. Lack nipples

b. Have some embryonic development outside the uterus

c. Lay eggs

d. Are found in Australia and Africa

What two major lineages make up the living Amniota?

Which statement is true about endothermy in mammals and birds?

a. They both inherited this trait from a common ancestor.

b. Birds are more closely related to mammals than to reptiles.

c. Endothermy arose independently in these two lineages.

d. Birds are reptiles and all reptiles are ectothermic.