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]

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

Fruit Dove

Iridescent Beetle

Spider Camouflaged as Lichen

Common Tube-Nosed Bat

Buff-Faced Pygmy Parrot

Litoria Sauroni

Striped Possum

Bosavi Silky Cuscus

Hairy Caterpillar

Two Black and Yellow Noctuids, which together resemble a snake

King Bird of Paradise