Turtles are extremely cute. I think we have probably all seen a turtle or even held one in our hands. But have you ever stopped to think about what makes their skin so tough?
Turtles are easily recognizable for their protective shells. But do turtles have scales in addition to their shells? As it turns out, most turtle species are covered in scales that provide an added layer of armor over their skin.
Turtle Shells vs. Scales
All turtles and tortoises have a shell made up of over 50 bones covered in interlocking plates called scutes. This top domed section is called the carapace, while the bottom is the plastron.
But the shell is not the only unique external feature of turtle anatomy. Most turtles are also covered in scales that protect their limbs, head, tail, and any exposed areas not covered by the shell.
Types of Turtle Scales
There are two main types of scales that form the exterior skin of most turtles:
- Scutes – The large, plate-like scales that cover the top and bottom shell.
- Plates – Smaller flat scales that cover legs, neck, heads, and tails.
The scutes overlaying the shell tend to be thicker and sturdier than the smaller plate scales on limbs and extremities. Both types provide external armor.
Benefits of Turtle Scales
A covering of external scales provides turtles with several advantages:
- Protection – Scales act as a shield against cuts, scrapes, bruises, and abrasions from terrain and predators.
- Moisture retention – Scales help lock in moisture and prevent dehydration.
- Thermoregulation – By absorbing or reflecting sunlight, scales aid temperature regulation.
- Hydrodynamics – Scales decrease drag and friction in water.
- Sensation – Scales contain nerve endings that provide sensory feedback.
The combination of shell and scales gives turtles tough, flexible, functional armor.
Turtles With Observable Scales
Here are some common turtle species where scales are clearly visible:
Box turtles |
Red-eared sliders |
Painted turtles |
Softshell turtles |
Snapping turtles |
You can easily view the scales on the limbs and head of terrestrial box turtles or colorful aquatic turtles like sliders and painteds. Scales are especially prominent on softshells with their leathery, scale-covered shells.
Exceptions – Turtles Without Scales
While having scales is the norm in most turtles, there are some exceptions:
- Sea turtles – Lack scales and have smooth skin and shells.
- Leatherback sea turtles – Shell is leathery without scutes.
- Mud & musk turtles – Have smooth, scale-free skin.
These specialized turtles evolved without scales to better suit their unique environments. But the vast majority of freshwater and land turtles retain protective scaling.
How To Care for Turtle Scales
Turtle scale health should be monitored and cared for by:
- Providing proper heat and UVB lighting.
- Ensuring adequate calcium and vitamins.
- Treating any fungal or bacterial shell infections.
- Filing down overgrown scutes if needed.
- Bathing regularly to hydrate scales.
Following proper turtle husbandry practices promotes smooth, healthy growth of scales.
Shedding in Turtles
Like other reptiles, turtles periodically shed their scales as they grow. During a molting cycle, scales flake off as new ones generate underneath.
Shedding allows the replacement of damaged scales and expansion to accommodate the turtle’s increasing size. It occurs naturally a few times per year.
Importance of Scales to Turtle Survival
The hardy scales of turtles played a key evolutionary role in their survival:
- Allowed adaptation from marine to freshwater and terrestrial environments.
- Provided defense against predators unable to penetrate tough shells and scales.
- Let turtles colonize habitats too harsh for exposed-skinned amphibians.
- Granted turtles great longevity by shielding them from weathering, injury, and elements.
Scales enable turtles to inhabit diverse ecosystems as well-protected, long-lived creatures.
Turtle Species With Modified Scales
Some turtles evolved highly specialized scales:
- Snapping turtles have saw-edged scales on their tails to ward off foes.
- Spiny softshells have cone-like points covering leathery shells.
- Matamatas have intricate scale-covered flaps that disguise their heads.
These unique variations enhance defense, blend into surroundings, or aid aquatic movement.
Modified scales demonstrate how evolution shaped turtle anatomy for survival.
The Distinctive Nature of Turtles
The combination of protective shells and armored scales sets turtles apart from all other animals. Their distinctive body covering allows turtles to inhabit environments too hazardous for most species. Turtles’ scaled exterior armor continues to help ensure their long-term success and longevity.
Fossil Evidence of Early Turtle Scales
Paleontologists have discovered fossil specimens showing that turtles developed their characteristic scales very early in their evolution:
- Odontochelys in 220 million year old Triassic sediments had a toothed beak and scales.
- Proganochelys fossils from 210 million years ago reveal fully developed turtle shells and scales.
- Primitive pre-turtle reptiles transitioned from lizard-like skin to scales and eventually full shells.
The fossil record indicates turtles were covered in protective scales alongside their shell armor even at their earliest stages.
Cultural Symbolism of Turtle Scales
The distinctive scales and shell of the turtle have made it culturally symbolic:
- In Native American mythology, the 13 scutes of the shell represent lunar months.
- Ancient Chinese tales portrayed a turtle’s 337 shell scutes as sacred numerology.
- Dream interpretation connects turtle shells and scales to emotional protection.
- Decorative mosaics use turtle shell and scale patterns in geometric designs.
Turtles’ unique armor has been inspirational in folklore, legends, art, and architecture around the world.
Turtle Scale Patterns and Colors
While the shapes are consistent, the colors and patterns of turtle scales vary greatly:
- Red-eared sliders have green scales with red and yellow eye patches.
- Box turtles display radiating stripes and spots on brown or yellow scales.
- Softshells have olive to tan soft leathery scales with dark blotched designs.
- Spider tortoises have intricate geometric black lines across their thick scutes.
There are over 300 turtle species with tremendous diversity in their scale colors, markings, and ornamentation.
Abnormalities in Turtle Scalation
In some cases, genetic mutations affect turtle scalation:
- Scute abnormalities where segments are fused or misaligned.
- Partial albinism where melanin in some scales fails to develop.
- Scales that are misshapen, overgrown, or asymmetrical.
- Partial or complete lack of scales resulting in smooth, exposed skin.
These conditions arise naturally from genetic variability or errors in embryonic development. But they do not affect turtle health or lifespan.
Want to learn more about turtles? Check out Small Types of Turtles
Threats to Turtles from Loss of Scales
While resilient, turtle scales can become damaged and detached:
- Injury from boats, motors, predators, falling, or being struck.
- Ulceration from poor water quality or malnutrition.
- Fungal or bacterial shell infections that penetrate layers.
- Parasitic infestations like leeches that weaken and separate scales.
Losing sections of shell and scales makes turtles vulnerable to pathogens, predators, and the elements. Proper handling and care minimizes these threats.
The Evolutionary Development of Turtle Scales
Primitive pre-turtle reptiles evolved scales and eventually full shells over millions of years:
-providing durable, lightweight armor
-enabling adaptation to new ecological niches
-transforming hydrodynamics for improved swimming
-allowing colonization of rivers, lakes, and land
This incremental development of rigid dermal scales and plates gave rise to the most distinctive characteristic of the ancient chelonian lineage.
Anytime I see a turtle, I can’t help but get excited. If they are small I want to pick them up, if they are large, I watch to scratch their underbellies!
Tell us what your favorite thing about turtles is in the comments below.
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