Click on the turtles to the right to view species specific taxonomic information
Click here for a Taxonomic Key to Caribbean Sea Turtles
1. Carapace covered with large horny plates; longitudinal carapace ridges, if present, not more than three in number and not of contrasting color; forelimbs much shorter than length of carapace; plastron color uniform or nearly so; carapace usually less than 60 mm (except in Natator) – see 2
1′. Entire surface of the animal (carapace, plastron and extremities) covered with small, soft, polygonal scales; seven longitudinal carapace ridges (including edges of shell) boldly outlined in white against a black background; forelimbs extremely long (almost as long as the carapace); plastron mottled black and white; typical carapace length (SCL) 60 mm (range 55-63 mm) – Dermochelys coriacea
2. Ventral coloration light; costal scutes four pairs – see 3
2′. Ventral coloration dark; costal scutes four to nine pairs – see 5
3. Overall coloration light: dorsum light olive-yellow and plastron white with a peripheral yellow band; broadly oval carapace; postorbital scales three pairs; relatively large size, typical carapace length (SCL) 61 mm (range 56.5-65.5 mm); confined to tropical Australia – Natator depressus.
3′. Carapace black or blue-black, typically with a white margin; plastron white; heart-shaped carapace (some posterior narrowing); postorbital scales usually four pairs (but sometimes three); typical carapace length smaller than Natator; tropical and subtropical seas including Australia – see 4
4. Forelimbs outlined in white; head scales blackish with narrow light (whitish) borders; postorbital scales usually four pairs; plastron pure white; typical carapace length (SCL) 49 mm (range 46-57 mm); distribution tropical and subtropical, not East Pacific region – Chelonia mydas
4′. Forelimbs and head scales sometimes outlined in white, but white edges may be reduced or absent; postorbital scales typically four pairs (but sometimes three); plastron initially white, but soon darkens; typical carapace length (SCL) 47 mm (range 41-52 mm); distribution Galapagos Islands and Meso-America – Chelonia mydas (Eastern Pacific, or black turtle)
5. Color brown (dark to light) above and below; inframarginal scutes typically three or four pairs – see 6
5′. Color very dark gray to black above and below; inframarginal scutes typically four pairs – see 7
6. Costal scutes four pairs; oval carapace; inframarginal scutes typically four pairs; typical carapace length (SLC) 42 mm (39-46 mm) – Eretmochelys imbricata
6′. Costal scutes five pairs; carapace broader in shoulder region than in Eretmochelys; inframarginal scutes typically three pairs; typical carapace length (SLC) 45 mm (38-50 mm) – Caretta caretta
7. Costal scutes usually five pairs; typical carapace length (SLC) 43 mm (38-46 mm); expected distribution of hatchlings Tamaulipas, Vera Cruz and South Texas (rare strays in southeastern USA) – Lepidochelys kempii
7′. Costal scutes usually six to nine pairs (sometimes five); typical carapace length (SLC) 42 mm (38-50 mm); distribution circumtropical, mostly mainland shore, not Gulf of Mexico and east USA – Lepidochelys olivacea
Source: Pritchard and Mortimer (1999), used with permission