Onychophora

views updated

Onychophora (velvet worms, Peripatus) A phylum comprising animals that combine annelid and arthropod features and that may be an evolutionary link between the two. They first appeared in the Cambrian (see AYSHEAIA PEDUNCULATA), since when they have changed little. The body is approximately cylindrical and slug-like, but covered with bands of tubercles covered by scales, and with 14 to 43 pairs of legs. The anterior bears antennae. The mouth is in a ventral position, flanked on either side by claw-like mandibles and oral papillae. Reproduction is oviparous, ovoviviparous, or viviparous. Many onychophorans are brightly coloured blue, green, or orange; others are black. There are about 70 species, found only in humid, tropical habitats.