For 200,000 years, life has flourished deep inside the crater of Mount Bosavi in complete isolation. Now a team of scientists has found it teeming with hairy caterpillars, fanged frogs, and the largest rats ever recorded.

A team of researchers from the US, UK, and Papua New Guinea launched an expedition inside Mount Bosavi, a now-dormant volcano that last erupted 200,000 years ago. The team discovered more than 40 new species, including 16 new species of frog — one with fangs — three previously unrecorded species of fish, and the Bosavi Woolly Rat, which has no fear of humans and is believed to be the largest rat ever recorded. There are no cats or monkeys located in the Bosavi crater, so the crater's main predators are giant monitor lizards. Below are a handful of the new and endangered species discovered by the team.

Lost world of fanged frogs and giant rats discovered in Papua New Guinea [Guardian]

Rodents of Unusual Size Found in Volcanic Lost World

Bosavi Woolly Rat, believed to be the largest rat ever recorded

Rodents of Unusual Size Found in Volcanic Lost World

Fruit Dove

Rodents of Unusual Size Found in Volcanic Lost World

Iridescent Beetle

Rodents of Unusual Size Found in Volcanic Lost World

Spider Camouflaged as Lichen

Rodents of Unusual Size Found in Volcanic Lost World

Common Tube-Nosed Bat

Rodents of Unusual Size Found in Volcanic Lost World

Buff-Faced Pygmy Parrot

Rodents of Unusual Size Found in Volcanic Lost World

Litoria Sauroni

Rodents of Unusual Size Found in Volcanic Lost World

Striped Possum

Rodents of Unusual Size Found in Volcanic Lost World

Bosavi Silky Cuscus

Rodents of Unusual Size Found in Volcanic Lost World

Hairy Caterpillar

Rodents of Unusual Size Found in Volcanic Lost World

Two Black and Yellow Noctuids, which together resemble a snake

Rodents of Unusual Size Found in Volcanic Lost World

King Bird of Paradise