Rarest of the rarest: top 10 lost amphibians

A Golden toad, Incilius periglenes, last seen in Costa Rica in 1989 Photograph: Conservation International

A Gastric brooding frog mother with cub, Rheobatrachus vitellinus, last seen in 1985 in Australia Photograph: Mike Tyler/Conservation International

Mesopotamia beaked toad, Rhinella rostrata, last seen in 1914 in Colombia Photograph: Paula Andrea Romero Ardila/Conservation International

A Jackson's climbing salamander, Bolitoglossa jacksoni, last seen in 1977 in Guatemala Photograph: Dave Wake/Conservation International

African painted frog, Callixalus pictus, last seen in 1950 in Rwanda Photograph: Society for the Study of Evolution/Conservation International

Rio Pescado stubfoot toad, Atelopus balios, last seen in 1995 in Ecuador Photograph: Luis Coloma/Conservation International

Turkesmanian salamander, Hynobius turkestanicus, last seen in Turkmenistan in 1909 Photograph: with permissions from Kuzmin S.L./Conservation International

Scarlet harlequin frog, Atelopus sorianoi, last seen in 1990 in Venezuela Photograph: Enrique La Marca/Conservation International

Hula painted frog, Discoglossus nigriventer, last seen in Israel in 1955 Photograph: Heinrich Mendelssohn/Conservation International

Samba stream frog, Ansonia latidisca, last seen in 1966 in Malaysia Photograph: Conservation International

Wanted alive: Conservation International's poster appealing for anyone who has spotted a missing amphibian to get in touch Photograph: Conservation International