Phylum Tardigrada share some characteristics with Arthropods.
Tardigrades secrete chitinous cuticles and molt periodically
Possess arthropod-like striated muscles.
Capacious body cavity appears to be a hemocoel, formed from spaces in the connective tissue.
Cuticle is highly permeable to air and water, so these animals are restricted to damp environments.
Possess 4 clawed appendages which are unjointed, and glands which resemble Malpighian tubules.