Aldabra giant tortoise
Aldabrachelys gigantea
Aldabra giant tortoises are often said to live well over a century, yet almost nobody can prove an exact age. This article looks at records, shell…
Turtles, Tortoises and Crocodilians
Armor, patience and very old family trees.
Turtles, tortoises and crocodilians look nothing alike, but they share a long family history and a similar way of living: armored bodies, slow metabolisms and eggs laid on land. Some have changed little in overall shape across a very long time, which is why they are sometimes called living fossils, a label scientists use loosely.
Here you will find a shell explained piece by piece, sea turtles that find their way back to the coast where they hatched, reptiles whose nest temperature helps decide the sex of the babies, and the alligator-or-crocodile question settled with a look at the snout. Several species in this category are under real pressure, and we say so plainly.
As with every category on the site, conservation statuses carry the date we looked them up. They can change, and the date tells you how fresh the information is.
Nine questions in this category
- Sea navigation
- The shell
- Long lives
- Alligator or crocodile
- Sex set by temperature
- Hibernation
- Bite force
- Nests
- Ancient origins
The species in this category
Play a round with any of them in the Terrarium to unlock the full article.
American alligator
Alligator mississippiensis
A broad U-shaped snout, lower teeth hidden behind the upper jaw and a freshwater home mark the American alligator. We test each clue against what…
Eastern box turtle
Terrapene carolina
The eastern box turtle can shut itself inside its shell because of a hinge in the lower plate. Behind that trick sits a shell built from ribs,…
Gharial
Gavialis gangeticus
The gharial's long, thin snout suits fish, not force: a 2012 test found its relative bite the weakest among living crocodilians. Two recent…
Green sea turtle
Chelonia mydas
In green sea turtles, the warmth of the nest, not a coin flip at conception, tips hatchlings toward male or female. A Great Barrier Reef study…
Loggerhead sea turtle
Caretta caretta
Baby loggerheads that have never seen the ocean swim the right way inside a tank of copied magnetic fields. Studies suggest adults use similar…
Nile crocodile
Crocodylus niloticus
A Nile crocodile nest is a hole in the ground, and the mother is its exit door: field studies describe her digging up eggs when the young squeak…
Painted turtle
Chrysemys picta
Painted turtles spend winter in cold pond mud, sometimes with almost no oxygen. Research points to a slowed body, a shell that soaks up acid, and…
Saltwater crocodile
Crocodylus porosus
A 2012 study put a force sensor under the back teeth of captive crocodilians. According to its authors, the strongest bite measured in any animal…