What is a list of animals that have a protective shell?

The animals that have shells are:

• Lobsters
• Turtles
• Crabs
• Snails
• Hermit Crabs
• Mussel [Sea Creature]
• Armadillos
• Northern Horse Mussel
• Northern Moon Snail
• Shrimps
• Wharf Crab
• Atlantic Horse Shoe Crab

Some of these animals might not have a protective shell.