Brain Pop Jr. does a great job of introducing Animal Classification. Lucky for us, their video on Animal Classification is one of the FREE videos. By watching this video the kids will learn about Vertebrates (animals that have a backbone) and Invertebrates (animals that do NOT have a backbone) followed by the characteristics of the 5 Vertebrate classes.
There are lots of other links on Brain Pop Jr. that correlate with this topic.
Talk About It
Another Vertebrate Video can be found here.
Here's another video on Vertebrates with Tim and Moby found here.
Here's a cool slide show and quiz on Scholastic's Study Jams website found here.
If you'd like some Vertebrate Printouts, you can visit visit Enchanted Learning's Website here.
Here's a model of a backbone!
Here is a diagram of a backbone.