bird bones are smaller and light weight, and this is why they can fly easier. if a mammal tried to fly, with its thick bones, it might wind up with shattered ones
caca
there are nervous
Dinosaurs were endotherms
A placental Mammal is a mammal that keeps the young inside the body until it can function independently.
This might be a trick question, since mammals do NOT hatch their young in eggs - that woulde be birds and reptiles.
It depends upon type of mammal and age of fossil .
A mammal that keeps the baby inside the body until it can function independently, and is a predator.
it extracts food and oxygen from the uterine wall of the mother to the fetus.
The same as the penis of any other mammal; to pass urine and sperm.
Every mammal has nipples. It is through the nipples that newborn mammals access the milk their mothers produce for them (the perfect food for a newborn mammal).
A mammal's brain is about 15 times heavier than the brain of a similarly sized fish, amphibian, or reptile.
Mammals have a closed Circulatory system. Parts of the system include a heart and veins. It is complex.