Lazarus species: 13 'extinct' animals found alive

This species has been hailed as the world's least-known bird. It is known only from a single specimen collected in 1867, and was long believed extinct. Then in Thailand in 2006, a wild population was discovered and confirmed to be large-billed reed-warblers via DNA matching to the original specimen. Today the birds largely remain a mystery, and unfortunately DNA sequence variation points to a stable or shrinking population structure.