An extinct species of Australian frog has been cloned by scientists who implanted a dead cell nucleus into an egg from another breed of frog.
The gastric brooding frog, or Rheobatrachus silus, swallowed its eggs, brooded its young in its stomach and then gave birth through its mouth.
It became extinct in 1983 but researchers at the University of New South Wales managed to recover cell nuclei from tissue samples collected in the 1970s. These samples were kept for 40 years in a deep freeze.
Scientists on the Lazarus Project have been trying to bring the species back from extinction by using the cell tissue.