| Main Ref. | Márquez, M.R., 1990 |
| Appearance refers to |
| specialized organs | |
| different appearance | |
| different colors | |
| remarks |
| Striking features | |
| Body shape lateral | |
| Cross section | |
| Dorsal head profile | |
| Type of eyes | |
| Type of mouth/snout | |
| Position of mouth | |
| Diagnosis | The olive ridley turtle has a slightly deeper body than the Kemp’s ridley. In adults; carapace nearly round; upturned on the lateral margins; flat on top; its width 90 percent of its length (Straight Curved Length (SCL)). Head: subtriangular; moderate-sized; averaging 22.4 percent of straight carapace length (SCL). Hatchlings: relatively bigger heads (39 percent SCL); longer carapaces (width 78 percent SCL); flippers comparatively bigger than in adults. In 3-year old juveniles: the carapace width, 93 percent of SCL; head length, 26 percent of SCL. Scales and scutes: same configuration as in the Kemp’s ridley; but the lateral scutes are often more than five pairs; the first pair is always in touch with the precentral scute. Also has openings of the Rathke’s glands on the plastral bridges; through a pore on the rear part of each inframarginal scute Fore flippers with 1 or 2 visible claws on the anterior border; sometimes another small claw in the distal part; rear flippers also with 2 claws. Males: larger more strongly curved claws; as well as a longer tail. Color: adults, plain olive-grey above; creamy or whitish; with pale grey margins underneath. Newborn hatchlings: when wet; almost completely black; sometimes with greenish sides; in general, become dark grey after drying. With growth; they change to grey dorsally and white underneath. |
| Ease of Identification | likely to be confused with closely related species. |
| Lateral Lines | Interrupted: No |
| Scales on lateral line | |
| Pored lateral line scales | |
| Scales in lateral series | |
| Scale rows above lateral line | |
| Scale rows below lateral line | |
| Scales around caudal peduncle | |
| Barbels | |
| Gill clefts (sharks/rays only) | |
| Gill rakers | |
| on lower limb | |
| on upper limb | |
| total | |
| Vertebrae | |
| preanal | |
| total |
| Attributes | |
| Fins number | |
| Finlets No. | Dorsal |
| Ventral | |
| Spines total | |
| Soft-rays total | |
| Adipose fin |
| Attributes |
| Fins number | |
| Spines total | |
| Soft-rays total |
| Pectoral | Attributes |
| spines | |
| soft-rays | |
| Pelvics | Attributes |
| Position | |
| spines | |
| soft-rays |