Leatherback Turtle

## Leatherback Sea Turtle

Class: Reptilia

Order: Testudines

Suborder: Cryptodira

Superfamily: Chelonioidea

Family: Dermochelyidae

Subfamily: Dermochelyinae

Genus: Dermochelys

Species: D. coriacea

The **leatherback sea turtle** (*Dermochelys coriacea*), sometimes called the **lute turtle** or **leathery turtle** or simply the **luth**, is the largest of all living turtles and is the fourth-heaviest modern reptile behind three crocodilians. They make their debut in "True Lovin'"

## Anatomy and Physiology

Leatherback turtles have the most hydrodynamic body design of any sea turtle, with a large, teardrop-shaped body. A large pair of front flippers powers the turtles through the water. Like other sea turtles, the leatherback has flattened forelimbs adapted for swimming in the open ocean. Claws are absent from both pairs of flippers. The leatherback's flippers are the largest in proportion to its body among extant sea turtles. Leatherback's front flippers can grow up to 2.7 m (8.9 ft) in large specimens, the largest flippers (even in comparison to its body) of any sea turtle.

The leatherback has several characteristics that distinguish it from other sea turtles. Its most notable feature is the lack of a bony carapace. Instead of scutes, it has thick, leathery skin with embedded minuscule osteoderms. Seven distinct ridges rise from the carapace, crossing from the cranial to caudal margin of the turtle's back. Leatherbacks are unique among reptiles in that their scales lack β-keratin. The entire turtle's dorsal surface is colored dark grey to black, with a scattering of white blotches and spots. Demonstrating countershading, the turtle's underside is lightly colored. Instead of teeth, the leatherback turtle has points on the tomium of its upper lip, with backwards spines in its throat (esophagus) to help it swallow food and to stop its prey from escaping once caught.

Oesophagus of a leatherback sea turtle showing spines to retain prey

*D. coriacea* adults average 1–1.75 m (3.3–5.7 ft) in curved carapace length (CCL), 1.83–2.2 m (6.0–7.2 ft) in total length, and 250 to 700 kg (550 to 1,540 lb) in weight. In the Caribbean, the mean size of adults was reported at 384 kg (847 lb) in weight and 1.55 m (5.1 ft) in CCL. Similarly, those nesting in French Guiana, weighed an average of 339.3 kg (748 lb) and measured 1.54 m (5.1 ft) in CCL. The largest verified specimen ever found was discovered in the Pakistani beach of Sanspit and measured 213 cm (6.99 ft) in CCL and 650 kg (1,433 lb) in weight

## Taxonomy

*Dermochelys coriacea* is the only species in genus *Dermochelys*. The genus, in turn, contains the only extant member of the family Dermochelyidae.

Domenico Agostino Vandelli named the species first in 1761 as *Testudo coriacea* after an animal captured at Ostia and donated to the University of Padua by Pope Clement XIII. In 1816, French zoologist Henri Blainville coined the term *Dermochelys*. The leatherback was then reclassified as *Dermochelys coriacea*. In 1843, the zoologist Leopold Fitzinger put the genus in its own family, Dermochelyidae. In 1884, the American naturalist Samuel Garman described the species as *Sphargis coriacea schlegelii.* The two were then united in *D. coriacea*, with each given subspecies status as *D. c. coriacea* and *D. c. schlegelii*. The subspecies were later labeled invalid synonyms of *D. coriacea.*

Both the turtle's common and scientific names come from the leathery texture and appearance of its carapace (*Dermochelys coriacea* literally translates to "Leathery Skin-turtle"). Older names include "leathery turtle" and "trunk turtle". The common names incorporating "lute" and "luth" compare the seven ridges that run the length of the animal's back to the seven strings on the musical instrument of the same name. But probably more accurately derived from the lute's ribbed back which is in the form of a shell.

### Evolution

Relatives of modern leatherback turtles have existed in some form since the first true sea turtles evolved over 110 million years ago during the Cretaceous period. The dermochelyids are relatives of the family Cheloniidae, which contains the other six extant sea turtle species. However, their sister taxon is the extinct family Protostegidae that included other species that did not have a hard carapace.

## Trvia

* In real-life leatherback turtles, are fully black, but in-show only their shell is black.