How do mammals differ from birds and reptiles?

Mammals have eggs inside them, but without a shell since it is not necessary. Once the egg has developed into a finished creature, the mammal gives birth to a living baby. Birds and reptiles lay eggs that later hatch outside the womb.

Mammals differ from other animals in that they possess fur, lack feathers, and the majority of them cannot fly, with the exception of certain species like bats.

Dinosaurs are also the common ancestor of birds and reptiles.

Mammals have endoskeletons; all other non-mammal insects have exoskeletons, which are composed of skeleton and soft tissue inside the body instead of skin.

Mammals differ from birds and reptiles in several ways:

1. Body temperature regulation: Mammals are endothermic, meaning they can regulate their body temperature internally. Birds are also endothermic, while most reptiles are ectothermic, relying on external sources of heat to regulate their body temperature.

2. Reproduction: Mammals give birth to live young and typically nurse their offspring with milk produced by mammary glands. Birds lay eggs with hard shells, and reptiles also lay eggs, but their eggs have soft, leathery shells.

3. Hair or fur: Mammals have hair or fur covering their bodies, providing insulation and protection. Birds have feathers, and reptiles have scales or scutes covering their bodies.

4. Respiratory system: Mammals typically have a diaphragm for breathing, while birds have air sacs connected to their lungs for efficient respiration. Reptiles have a different lung structure compared to mammals and birds.

5. Skeletal system: Mammals have specialized skeletal features, such as different types of teeth, while birds have lightweight bones adapted for flight. Reptiles have skeletal characteristics suited for their various habitats, such as limbs for terrestrial movement or fins for swimming.