Planipapillus is a genus of velvet worm in the Peripatopsidae family.

For this reason, velvet worms are dependent upon habitats with high air humidity.

These are also found on the two antennae, which can be regarded as the velvet worm's most important sensory organs.

For a long time, velvet worms were also considered related to the annelids.

Due to their structural conservatism, the velvet worms were thus considered "living fossils".

Fossils from the early Cambrian bear a striking resemblance to the velvet worms.

The modern velvet worms form a monophyletic group, incorporating all the descendants of their common ancestor.

The velvet worm, which looks like a slug with many legs, has been the focus of a continuing scientific debate over its lineage.

Named for its soft skin, the velvet worm was long thought to be a close relative of both the earthworm and the centipede.

These velvet worms are prized as pets due to their bizzare appearance.