Why are whales so big? Why are giraffe's necks so long? Here are the origins of 10 iconic features in the animal kingdom.

Jonathan, the world's oldest tortoise, has turned 191, living through 40 U.S. presidents and 31 St. Helena governors.

In this extract from the new book Beautiful Experiments: An Illustrated History of Experimental Science, science writer Philip Ball explains how Isaac Newton transformed our understanding of light.

In this extract from the new book Blue Machine: How the Ocean Works, oceanographer Helen Czerski explains the ingenious way turtles contend with the extreme saltiness of the sea.

The known population of the Yangtze giant softshell turtle is now just two males. Experts said that if the female had survived, she could have "laid a hundred eggs or more a year."

A previously unknown extinct tortoise was revealed in an investigation on these giants' evolutionary history.

Almost all sea turtle hatchlings are emerging from their eggs as females on some Florida beaches. What's going on?

Some freshwater turtles engage in a process akin to butt breathing.

A new study into the fossilized remains of an ancient turtle in Romania has revealed a brand-new species that managed to survive when the nonavian dinosaurs could not.

Some species of turtles age very slowly or not at all, according to new studies of both captive and wild populations. How do they do it?