You can tell if a turtle is a sea turtle primarily by its streamlined shell, non-retractile head and limbs, and flipper-like appendages.
Identifying Characteristics of Sea Turtles
Several key characteristics distinguish sea turtles from other types of turtles:
- Shell Structure: Sea turtles have a large, streamlined shell, which is adapted for swimming efficiently in the ocean.
- Non-Retractile Limbs and Head: Unlike land turtles or freshwater turtles, sea turtles cannot pull their head or limbs inside their shell for protection.
- Flipper-Like Limbs: Sea turtles have flippers instead of feet. These flippers are perfectly adapted for swimming, but make them awkward and vulnerable on land.
Sea Turtle vs. Other Turtles
| Feature | Sea Turtle | Land/Freshwater Turtle |
|---|---|---|
| Shell | Streamlined, relatively flat | Domed, varies in shape |
| Limbs | Flippers | Legs with claws |
| Retractability | Cannot retract head/limbs | Can retract head/limbs |
| Habitat | Primarily marine | Terrestrial or freshwater |
Vulnerability on Land
Because their flippers are designed for swimming and they cannot retract into their shells, sea turtles are particularly vulnerable to predators and other dangers when they are on land, such as during nesting season.
