"Common Name: Green sea turtle - named for the green color of the fat under its shell. (In some areas, the Pacific green turtle is also called the black sea turtle.)
Scientific Name: Chelonia mydas
Description: They are easily distinguished from other sea turtles because they have a single pair of prefrontal scales (scales in front of its eyes), rather than two pairs as the other sea turtles have. Head is small and blunt with a serrated jaw. Carapace is bony without ridges and has large, non-overlapping, scutes (scales) present with only 4 lateral scutes. Body is nearly oval and is more depressed (flattened) compared to Pacific green turtles. All flippers have 1 visible claw. The carapace color varies from pale to very dark green and plain to very brilliant yellow, brown and green tones with radiating stripes. The plastron varies from white, dirty white or yellowish in the Atlantic populations to dark grey-bluish-green in the Pacific populations. Hatchlings are dark-brown or nearly black with a white underneath and white flipper margins.
For comparison, the Pacific green turtle (aka Black Sea Turtle) has a body that is strongly elevated or vaulted and looks less round in a frontal view than other green sea turtles. The color is where you see the biggest difference with Pacific greens having a dark grey to black carapace and the hatchlings are a dark-brown or black with narrow white border with white underneath.
Size: Adults are 3.5 to 4 feet in carapace length (76-91 cm). The green turtle is the largest of the Cheloniidae family. The largest green turtle ever found was 5 feet (152 cm) in length and 871 pounds (395 kg).
Weight: Adult weigh between 300 to 400 pounds (136-180 kg).
Diet: Changes significantly during its life. When less than 8 to 10 inches in length eat worms, young crustaceans, aquatic insects, grasses and algae. Once green turtles reach 8 to 10 inches in length, they mostly eat sea grass and algae, the only sea turtle that is strictly herbivorous as an adult. Their jaws are finely serrated which aids them in tearing vegetation.
Habitat: Mainly stay near the coastline and around islands and live in bays and protected shores, especially in areas with seagrass beds. Rarely are they observed in the open ocean.
Nesting: Green turtles nest at intervals of 2, 3, or more years, with wide year-to-year fluctuations in numbers of nesting females. Nests between 3 to 5 times per season. Lays an average of 115 eggs in each nest, with the eggs incubating for about 60 days.
Range: Found in all temperate and tropical waters throughout the world."
Info thanks to Green turtles.
One species is so solitary that it’s future is unknown:
"Common Name: Australian flatback - named because its shell is very flat.
Scientific Name: Natator depressus
Description: Head has a single pair of prefrontal scales (scales in front of its eyes). Carapace is bony without ridges and has large, non-overlapping, scutes (scales) present with only 4 lateral scutes. Carapace is oval or round and body is very flat. Flippers have 1 claw. Edge of carapace is folded and covered by thin, non-overlapping waxy scutes. Carapace is olive-grey with pale brown/yellow tones on margins and the flippers creamy white. The scutes of the hatchlings form a unique dark-grey reticulate pattern, and the center of each scute is olive colored.
Size: Adults measure up to 3.25 feet in carapace length (99 cm).
Weight: Adults weigh an average of 198 pounds (90 kg).
Diet: Apparently eats sea cucumbers, jellyfish, mollusks, prawns, bryozoans, other invertebrates and seaweed.
Habitat: Prefer turbid inshore waters, bays, coastal coral reef and grassy shallows.
Nesting: Nests 4 times per season. Lays an average of 50 eggs at time, but these are comparatively quite large. The eggs incubate for for about 55 days. When the hatchlings emerge, they are larger than most species.
Range: Very limited. It is found only in the waters around Australia and Papua New Guinea in the Pacific."
Info thanks to Flatback Turtles.
