These intertwined velvet worms, or onychophorans (meaning claw bearers), are living fossils, holdovers of the Cambrian explosion of life-forms that occurred about 530 million years ago. The small, terrestrial (land-dwelling) worms look rather like caterpillars, with antennae and clawed legs down the whole length of their bodies. They live in moist places, such as rotting logs and leaf litter. They are quite secretive and display ‘photonegative' behaviour, meaning they hide away from light. Although first mistakenly described in 1826 as a type of slug, the evolutionary history of onychophorans has long fascinated scientists. They have been described as a missing link between the arthropods (a group that includes insects and spiders) and the annelids, or segmented worms (which includes earthworms and beach worms). To date, only a couple of hundred species of onychophorans are known, but it is very likely that many more remain to be discovered and described. __
