What has a spine but no bones?

How to think about it

1. A spine with no bones is a spine in name only, so look for objects with a part called that.
2. Think of the narrow edge you see when something stands on a shelf.
3. That edge is where the title is printed so you can find it.
4. A book has a spine and not a single bone.

Why “a book” is the answer

The spine of a book is the bound edge that faces out on a shelf, where the title and author usually appear. It holds the pages together the way a backbone holds a body, which is how it got the name, but it contains paper and glue, not bone. The riddle lives on that borrowed word.

Common wrong answers

• A jellyfish. A jellyfish has no bones and no spine either, so it fails the first half.
• A cactus. Cactus spines are sharp needles, and a cactus has many of them, not one.