Original: The Lord Howe Island stick insect, Dryococelus australis, is a species of stick insect which lives on the Lord Howe Island Group. It was thought to be extinct by 1930, only to be rediscovered in 2001 (this phenomenon is known as the Lazarus effect).
Simplified: The Lord Howe Island stick insect (Dryococelus australis) was thought to have died out in 1930, but more were found in 2001.