Animal Skeletons: How Animals Move

Year 3 Science Exploring Different Types of Skeletons How Skeletons Help Animals Survive

Learning Objectives

Identify three types of animal skeletons Explain how skeletons help animals move Give examples of animals with different skeleton types Understand how skeletons help animals survive

What Do You Think?

Do all animals have the same type of skeleton? How do you think a fish's skeleton is different from a crab's? What helps an octopus move without any bones?

Three Types of Skeletons

Endoskeleton - Bones Inside

Bones are inside the body Made of hard bone material Grows as the animal grows Examples: fish, birds, mammals, reptiles

Exoskeleton - Hard Shell Outside

Hard covering on the outside of the body Like wearing armor all the time Must shed and grow new shells Examples: insects, crabs, lobsters, spiders

Hydrostatic Skeleton - Water Power

No hard bones or shells Uses water pressure to move Muscles squeeze water to create movement Examples: octopus, jellyfish, worms, slugs

How Skeletons Help Animals Move

{"left":"Endoskeleton: Muscles pull on bones to create movement, like levers\nExoskeleton: Muscles attach to inside of shell, joints bend like hinges","right":"Hydrostatic: Muscles squeeze water to extend and contract body parts"}

Mission Assignment: Animal Skeleton Detectives

Work in pairs to research one animal Find out what type of skeleton it has Discover how its skeleton helps it move Prepare to share your findings with the class

Plenary: What Have We Learned?

Can you name the three types of skeletons? Which animals have bones inside their bodies? How does an octopus move without bones? Why do crabs need to shed their shells?