This one-ton turtle once ruled South America’s rivers — until a changing planet proved too much for even the largest freshwater giant.

The discovery, in China, of the oldest known turtle fossil has turned palaeontologists' understanding of the species' origin and ecology on its head. The fossil of Odontochelys semitestacea was found ...

"They show now how developmental steps [in the turtle] could have led to this initial formation" of the turtle's shell. In addition to the overt peculiarity of the turtle's shell, or carapace -- which ...

Francis Horne, a biologist who studies shell formation at Texas State University, offers this answer. The exoskeletons of snails and clams, or their shells in common parlance, differ from the ...

Turtles are pretty mellow creatures, but they excel at causing strife among paleontologists. Researchers have long been left guessing as to how soft-backed animals somehow transitioned into the ...