Abdominal
The largest pair — middle of the belly. Where you'll see the male's concave dish most clearly.
Male vs female: how to tell
Tortoise sex is read from the back end of the animal, not the head. None of these signs are reliable in hatchlings — you usually need a juvenile that's been growing steadily for a few years before the differences are obvious.
| Trait | Male | Female |
|---|---|---|
| Plastron (underside) | Concave — scooped inward so he can sit on top of the female during mating. | Flat or slightly convex — gives more room for carrying eggs. |
| Tail | Long, thick, often tucked sideways under the shell. Vent (cloaca) sits past the edge of the carapace. | Short and stubby. Vent sits at or inside the edge of the carapace. |
| Anal scutes | Wider V-shaped notch at the back of the plastron to let the tail swing. | Narrower, more closed notch. |
| Size | Smaller in most species (yellow-foot, red-foot, Russian, Greek). | Larger overall in those same species — opposite of Sulcatas and leopards, where males are bigger. |
| Behavior | More territorial. Head-bobs, ramming, mounting attempts once mature. | Generally calmer; digs nesting pits when gravid. |
| Reliable age to sex | Usually 4–6 years / palm-sized; earlier in fast growers. | Same window — hatchlings cannot be reliably sexed by eye. |
Note on temperature-dependent sex: in most tortoises, incubation temperature decides the hatchling's sex. Warmer eggs (~31–32 °C) usually produce females; cooler eggs (~27–28 °C) usually produce males.
Tortoises of the world
There are roughly 50 recognized tortoise species spread across every continent except Australia and Antarctica. These are the ones you're most likely to read about — wild, in captivity, or in conservation news.
Wikimedia CommonsYellow-foot tortoise
Chelonoidis denticulatusAmazon basin — Brazil, Peru, Colombia, the Guianas, Venezuela
Size: 16–24" carapace, 30–60 lb
Rainforest tortoise. Loves humidity, eats more fruit and mushrooms than most tortoises, and will eat carrion and slow-moving invertebrates. Shelldon's species.
Wikimedia CommonsRed-foot tortoise
Chelonoidis carbonariusNorthern South America & southern Central America — savanna edges and dry forest
Size: 11–14" carapace, 20–30 lb
Closest cousin to the yellow-foot but smaller, more colorful (bright red scales on legs/head), and more tolerant of drier conditions.
Wikimedia CommonsSulcata (African spurred)
Centrochelys sulcataSahel — Senegal, Mali, Chad, Sudan, Ethiopia
Size: 24–36" carapace, 70–200 lb
Third-largest tortoise on Earth. Grassland grazer, prolific burrower. Wildly under-estimated as pets — adults need outdoor space and a heated shed.
Wikimedia CommonsLeopard tortoise
Stigmochelys pardalisEastern and southern Africa — savanna and dry scrub
Size: 16–18" carapace, 30–50 lb
Beautiful spotted shell. Pure grazer, no fruit. Does not dig burrows — needs surface shelter from heat and cold.
Wikimedia CommonsRussian tortoise
Testudo horsfieldiiCentral Asia — Afghanistan, Iran, Pakistan, Uzbekistan, Kazakhstan
Size: 6–10" carapace, 1–3 lb
Small, hardy, only four claws per foot. Built for short hot summers and long burrow brumation. Easiest "true" tortoise for cold climates.
Wikimedia CommonsHermann's tortoise
Testudo hermanniMediterranean Europe — Italy, Spain, the Balkans, Greece
Size: 6–11" carapace, 4–8 lb
Classic European garden tortoise. Distinctive tail-tip spur. Brumates through winter. Long-lived — 50–100 years in good care.
Wikimedia CommonsGreek (spur-thighed) tortoise
Testudo graecaMediterranean — North Africa, the Middle East, southern Europe
Size: 5–10" carapace, 2–7 lb
Named for the spurs on each thigh, not for Greece. Many subspecies across a huge range — varies wildly in size and color.
Wikimedia CommonsIndian star tortoise
Geochelone elegansDry scrub of India, Sri Lanka, and southeast Pakistan
Size: 7–12" carapace, 3–15 lb
Striking yellow starburst pattern on each scute. CITES Appendix I — heavily protected; legal captive lines only.
Wikimedia CommonsGalápagos tortoise
Chelonoidis niger complexGalápagos Islands, Ecuador
Size: Up to 60" carapace, 500–900 lb
Largest living tortoise. Multiple island-specific subspecies with saddleback or domed shells matched to their food height. Can live 150+ years.
Wikimedia CommonsAldabra giant tortoise
Aldabrachelys giganteaAldabra Atoll, Seychelles
Size: Up to 48" carapace, 500–700 lb
The other living giant. Almost wiped out in the 1800s; one of conservation's earliest comeback stories.
Wikimedia CommonsPancake tortoise
Malacochersus tornieriRocky outcrops of Kenya and Tanzania
Size: 6–7" carapace, under 1 lb
Flat, flexible shell — it wedges into rock cracks and inflates itself with air so predators can't pull it out. Endangered.
Wikimedia CommonsBurmese star tortoise
Geochelone platynotaDry zone of central Myanmar
Size: 10–14" carapace, 10–25 lb
Functionally extinct in the wild by 2000; rebuilt from a few dozen captive animals — one of the most successful tortoise recoveries ever.
The underside (plastron)
A tortoise's underside is called the plastron. It's the second half of the shell — fused to the upper dome (the carapace) by a bony bridge on each side. The plastron is made of paired scutes, and once you can name them, sexing and health checks get a lot easier. Tap a region to inspect it.
Reading the shell
A tortoise's shell is a living record of how it's been kept. Growth rate, humidity, diet, lighting, and injury all leave marks. Tap a concept to see it on the shell.
Growth rings
The concentric ridges inside each scute are growth bands — new keratin laid down as the tortoise grows. They're not annual like tree rings: a fast-growing hatchling can lay down several in a year, an adult might add almost none. Wide, evenly spaced rings = steady growth. Cramped, irregular rings = stop-start growth (often diet or temperature swings).
None of this replaces a reptile vet. Use it to know when something looks off, then get a professional opinion — especially for shell rot, MBD, or any crack.