Final answer:
Mammals are the vertebrate group characterized by internal fertilization, amniotic egg, skin that resists drying, and heavy bones.
Step-by-step explanation:
The vertebrate group that is characterized by internal fertilization, amniotic egg, skin that resists drying, and heavy bones is mammals. Mammals have evolved several adaptations to live on land, including the amniotic egg which allows them to reproduce away from water. Their skin is also covered in hair or fur, which helps in resisting drying and regulating body temperature. Lastly, mammals have heavy bones that provide support and protection.