AT A GLANCE
- Common Name: Leatherback Sea Turtle
- Scientific Name: Dermochelys coriacea
- Category: Reptiles
- Subcategory: Sea Turtles
- Size: Carapace length: 4.5–6.0 ft (1.4–1.8 m); Total length: 6–7 ft (1.8–2.2 m); Flipper span: 8.5–10.0 ft (2.6–3.0 m)
- Weight: 550–1,500 lb (250–700 kg); verified maximum weight 2,019 lb (916 kg); largest extant turtle on Earth
- Lifespan: 45–50+ years in the wild; precise longevity remains under scientific investigation
- Diet: Carnivore / Gelatinivore (consumes almost exclusively jellyfish, salps, siphonophores, and pelagic tunicates)
- Habitat: Pelagic open ocean, continental shelf waters, and tropical sandy nesting beaches
- Range: Circumglobal across all tropical, subtropical, and subpolar oceans (Atlantic, Pacific, and Indian Oceans); ranges as far north as Alaska and Norway and south to New Zealand
- Conservation Status: Vulnerable (IUCN Red List / Pacific sub-populations are critically endangered due to fishery bycatch)
Overview
The Leatherback Sea Turtle (Dermochelys coriacea) is the colossal, ancient monarch of the marine chelonian world, holding the undisputed scientific title of the largest living turtle on Earth. Belonging to the family Dermochelyidae—a lineage that diverged from all other sea turtles over 100 million years ago during the age of the dinosaurs—the leatherback is unique among living turtles because it has no hard, bony shell. Instead, its streamlined, barrel-shaped carapace is encased in a thick, leathery matrix of oily cartilage embedded with thousands of microscopic bony plates (osteoderms).
A true ocean voyager capable of trans-oceanic migrations exceeding 10,000 miles across entire ocean basins, Dermochelys coriacea defies the thermal limits of reptilian biology. Through a suite of physiological adaptations known as gigantothermy—including counter-current heat exchangers and dense brown adipose tissue—the leatherback can maintain an internal body temperature up to 18 degrees Celsius above surrounding water, allowing it to plunge into subpolar Arctic waters and dive past 4,000 feet into the abyssal depths to hunt giant jellyfish.
Biology and Physical Characteristics
The anatomical construction of Dermochelys coriacea is a triumph of hydrodynamic engineering. Its tear-drop carapace is reinforced by seven prominent longitudinal ridges that minimize water drag, while its enormous, clawless front flippers can span 10 feet across, acting as massive underwater wings that propel the 1,000-pound reptile with effortless grace. Because jellyfish consist of over 95 percent water and provide low caloric density, the leatherback has evolved backward-pointing, razor-sharp keratinized spines (papillae) that line its entire mouth, pharynx, and deep esophagus; these formidable spines prevent slippery jellyfish from escaping as the turtle expels excess seawater before swallowing.
Behavior and Ecology
Leatherbacks are solitary pelagic wanderers that spend almost their entire lives in the open ocean, coming ashore only to lay eggs. They are the deepest-diving air-breathing marine reptiles on Earth, with recorded dives reaching an astonishing 4,200 feet (1,280 meters)—depths where hydrostatic pressures exceed 120 atmospheres and water temperatures drop near freezing. Every two to three years, mature females return across thousands of miles of open sea to the exact tropical sandy beaches where they were born, hauling their massive bulk ashore under cover of darkness to excavate deep nesting pits and deposit clutches of 60 to 100 ping-pong-ball-sized eggs before retreating back into the surf.
Conservation and Human Impact
Dermochelys coriacea is globally categorized as Vulnerable on the IUCN Red List, with several regional sub-populations—particularly in the eastern and western Pacific—officially categorized as Critically Endangered, having collapsed by over 90 percent in the last three decades. The single most lethal threat to leatherbacks is entanglement and drowning in industrial pelagic longlines and coastal gillnets targeting tuna and swordfish. Furthermore, plastic pollution poses a catastrophic hazard, as drifting plastic bags and balloons are visually identical to jellyfish and cause fatal gastrointestinal impactions when ingested.
Interesting Factoid
The leatherback sea turtle’s mouth and throat are lined with hundreds of sharp, backward-pointing fleshy spikes called papillae that point down toward its stomach, ensuring that slippery jellyfish cannot slide back out while the turtle swallows.