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Wondiwoi Tree Kangaroo

scientific name: Dendrolagus mayri

Last seen: 1928 in Indonesia

Years lost: 90

The mystery surrounding the Wondiwoi Tree Kangaroo has taken on legendary proportions. When the kangaroo was found in the Wondiwoi Peninsula of West Papua in mossy montane forests at an elevation of 1,600 meters, scientists couldn’t figure out how it came to inhabit the higher parts of the Wondiwoi Peninsula—the answer remains elusive as an enduring “zoo-geographical mystery.” Everything we know about the Wondiwoi Tree Kangaroo comes from a single individual, an adult male collected in 1928 by one of the world’s leading evolutionary biologists, Ernst Mayr.