1. Exoskeleton: Arthropods have an exoskeleton made of chitin, which provides support, protection, and waterproofing. This allowed them to retain moisture and survive in drier environments than mammals.
2. Jointed Appendages: Arthropods have jointed appendages that allow for a wide range of movements and functions, such as walking, climbing, burrowing, and grasping. This versatility allowed them to adapt to different habitats and food sources.
3. Tracheal System: Arthropods have a tracheal system that allows for efficient respiration on land. This system consists of tiny tubes that carry oxygen directly to cells throughout the body.
4. Smaller Size: Arthropods are generally smaller than mammals, which allowed them to find shelter more easily and exploit smaller food sources.
5. Earlier Evolutionary History: Arthropods appeared on Earth much earlier than mammals, giving them more time to adapt and diversify into different forms.
As a result of these advantages, arthropods were able to successfully colonize land and become the most diverse animal group on Earth.