Sand dollars are marine invertebrates with flat, disk-shaped shell. They are echinoderms and have spines when alive. Sand dollars are found in sandy sea floor and in shallow ocean waters.MSN Encarta: Sand Dollar
Classification
- Kingdom: Animalia
- Phylum: Echinodermata
- Class: Echinoidea
- Order: Clypeasteroida
- Type: Invertebrate