Which extinct amphibian from Costa Rica was last seen in 1989?

Which extinct amphibian from Costa Rica was last seen in 1989? The answer is the golden toad, Incilius periglenes. It was endemic to a tiny area of high-elevation cloud forest near Monteverde in northern Costa Rica.

The species was first described by herpetologist Jay Savage in 1966, although he discovered it in 1964. For years, breeding gatherings could include around 1,500 adults. The decline was startling: only about 10 or 11 individuals were seen in 1988, and the last verified sighting was a solitary male observed by researcher Martha Crump on 15 May 1989.

The golden toad became an emblem of the global amphibian decline crisis. Its disappearance has been linked to several interacting possibilities, including unusually dry and warm conditions associated with El Niño, climate variability, its extremely restricted range, and disease such as chytridiomycosis. No explanation alone is universally accepted as the complete cause.

The International Union for Conservation of Nature listed the species as extinct in the mid-2000s after extensive searches found no survivors. Its vivid orange males and unusually varied females made it one of Costa Rica's best-known lost animals.