National Geographic UK - 10.2019

Shell length: about 7 ft

Weight: up to 2 tons

Stomach

300 ft

3 ft

2.3 ft

835 ft

Brain

Salt

glands

Skin Bone

Lungs

Liver

6 ft

4,000 ft

3 in Fat

Esophagus

Ribs

Scute

Vein

cool

blood

Artery

warm

blood

INDIANOCEAN

PAC.OC.

ATL.OC.

SOUTHAMER.

EUROPE NORTHAMERICA

ANTARCTICA

AUS.

ASIA

AFRICA

OREGON, U.S.

NEW GUINEA

12 ,^774 mi

documentedLongest

sea turtlemigration

MAP SOURCES: SCOTT BENSON, SOUTHWEST FISHERIES SCIENCE CENTER, NOAA; STATE OF THE WORLD’S SEA TURTLES (SWOT), OBIS-SEAMAP

FLEXIBLE SHELL

Leatherbacks are the only living

species with unfused ribs, rubbery

skin over layers of connective tissue,

and a flexible shell of bony plates.

The hawksbill is

the only turtle with

overlapping scutes

and serrated edges

on its shell.

HAWKSBILL

Eretmochelys imbricata
Hawksbills’ intricately patterned, trans-
lucent scutes have long been used to
decorate jewelry and luxury items.

OLIVE RIDLEY

Lepidochelys olivacea

The most abundant species exits

the sea en masse to nest, a safety-in-

numbers strategy against predators.

LEATHERBACK

Dermochelys coriacea

The largest and deepest diving

turtle makes the longest migrations

and can weigh up to 2,000 pounds.

Slippery diet

A long, barbed esoph-

agus traps jellyfish and

keeps them moving

into the stomach.

Migration cue

Pale skin lets light into

the pineal gland, which

can track day length

and spur migration.

Archelon (extinct)
This giant that roamed the
seas 75 million years ago had
unfused ribs, like its close rela-
tive, the modern leatherback.

Waxy skin covers a shell

of coin-size bony plates

that can withstand the

pressure of deep dives.

Transferring heat

Blood flowing to flippers

warms returning cold blood,

maintaining a warmer core

than hard-shell turtles have.