Largest onychophoran

The world's largest species of onychophoran or velvet worm is Solórzano's velvet worm Peripatus solorzanoi, which measures up to 22 cm long, and was discovered in 1996 by herpetologist Alejandro Solórzano, but was not formally described and named until 2010. It is native to Guayacán de Siquirres in Costa Rica. Males have 34 pairs of claw-bearing legs or oncopods, while females have 39–41 pairs.

Together with true arthropods and tardigrades or water-bears, velvet worms are housed within the major taxonomic division Panarthropoda ("all arthropods"), and its members are morphologically united by virtue of their segmented bodies, ventral nervous system, and their possession of legs and claws.

Uniquely, the velvet worms are entirely endemic to terrestrial environments; there are no amphibious or aquatic species.