Peripatus

Peripatus-Evolutionary significance

1. Peripatus
 Peripatus is a genus of velvet worms in the Peripatidae family.
 The genus Peripatus is found in Central America, the Caribbean and northern South
America.
 Peripatus is a carnivores, predaceous and nocturnal arthropod found commonly in
crevices of rocks, under stones and wood in tropical regions.
 Body cylindrical, elongated and without true segmentation and exoskeleton.
 Skin velvety and is thrown into numerous transverse grooves (wrinkles), which bear
spiny papillae.

 Distinct head is absent but anterior end bears a pair of segmented antennae.
 At their base a pair of jaws, a pair of eyes and a pair of oral papillae having slime gland
are present.
 Along the body, 14 pairs of un-segmented appendages are present on lateral sides.
 Excretion through nephridia.
 Sexes are separate and they are mostly viviparous.
 This group has long been regarded as important in evolutionary biology due to their
phylogenetic position, ancient history and Gondwanan distribution.
 It is called living fossil and acts as connecting link between Annelida and
Arthropoda and exhibits following similarities:
Annelidan affinities:
1. Presence of paired nephridia.
2. Presence of straight alimentary canal.
3. Presence of un-segmented stumpy appendages.
4. Presence of simple eyes.
Arthropod affinities:

2. 1. Presence of tracheal system
2. Presence of chitinous cuticle
3. Presence of jaws
4. Presence of antennae