THE ANIMAL FILES

Leatherback sea turtle

Dermochelys coriacea

A leatherback’s flexible back still contains tiny bones.

Leatherback sea turtles travel through the ocean using large front flippers. Their backs lack the large scutes familiar on many turtles, instead bearing leathery skin and embedded small bones. Feeding on soft-bodied prey and retaining heat are central to their ocean-going life.[1]

Follow the evidence ↓
Leatherback sea turtle
Image: Julien Renoult · Commons · CC BY 4.0
Back
Leathery covering with embedded osteoderms[1]
Food emphasis
Jellyfish and other soft-bodied prey[1]
Propulsion
Large front flippers[1]

A different kind of turtle back

Seven longitudinal ridges run along the back. The covering lacks broad horny scutes, but small osteoderms remain embedded within the skin. “No hard plated shell” should therefore not become “no bone anywhere in the back.” Researchers have proposed that the flexible covering accommodates changes in fat reserves used for insulation and long migrations.[1]

Holding slippery food

Jellyfish are major prey, with other soft-bodied animals also eaten. Backward-pointing structures in the throat help keep food from escaping as it is swallowed. The animal has no chewing teeth. Soft prey does not imply that capturing and transporting it into the digestive tract requires no specialised structures.[1]

Keeping muscle heat

Active swimming produces heat, while large body size, insulating fat and countercurrent heat exchangers help retain it. Studies do not require an exceptionally high resting metabolism to explain warm adult bodies. Heat production and heat conservation work together, allowing a moving turtle to remain warmer than surrounding water.[1]

A COMMON MIX-UP

Does its leathery back contain no bone?

No. Small osteoderms are embedded in the skin even though large scutes are absent.[1]

TRY A LITTLE REASONING

Why does insulation help only by retaining heat, rather than creating it?

Reveal the explanation

Swimming muscles produce heat; fat and heat exchangers reduce its loss to the water. The two roles are distinct.[1]

Sources & editorial notes

Adapted and translated from the cited Wikipedia revisions, with source-linked reasoning. Image credit and licence are listed separately above.

Adapted and translated from Wikipedia contributors; exact revisions are linked below. CC BY-SA 4.0

  1. Wikipedia contributors — Dermochelys coriacea (adapted and translated; exact revision)
  2. NCBI Taxonomy — Dermochelys coriacea (identity and game lineage)

Last fact check:

One discovery leads to another

Loggerhead sea turtleStrong jaws meet a life that begins among floating weeds.Caretta caretta ↗Green sea turtleThe green in the name is not a promise about the shell.Chelonia mydas ↗Hawksbill sea turtleA narrow hooked beak reaches food among reef structures.Eretmochelys imbricata ↗