Many animals have spines or spine-like structures:
- Mammals: Hedgehogs, porcupines, echidnas, and tenrecs have modified hair or skin spines for defense.
- Fish: Sharks, rays, lionfish, and others have fin-associated spines.
- Amphibians: Some frogs and salamanders have bony skin protrusions.
- Invertebrates: Sea urchins, sea stars, and some insects and spiders have spines or thorn-like projections.
- Others: The spiny anteater and several spined lizard species also feature protective spines.
The term "spine" may refer to the vertebral column or to various hard, pointed surface structures depending on context.