1 7 Sipunculoidea — Arthropoda 



Class Subcl Order 

 CHAETOPODA 



Polychaeta polychaetes 



Errantia sandworms 



Sedentaria tubeworms 

 Oligochaeta earthworms, angle-worms, night-crawlers, oligochaetes 



Plesiothecata 



Prosothecata 



Prosopora 



Opisthopora 

 HIRUDINEA leeches, bloodsuckers 



Rhynchobdellida 



Gnathobdellida 



Pharyngobdellida 



Acanthobdellida 

 ARCHIANNELIDA 



Archiannelida 



TAR DIGRADA 



bear-animalcules, water-bears 



HETEROTARDIGRADA 



Arthrotardigrada 

 Echiniscoidea 

 EUTARDIGRADA 



Eutardigrada 



PENTASTOM I DA 

 LINGUATULIDA 



Cephalobaenida 

 Porocephalida 



ONYCHOPHORA 



PERIPATIDEA 



Euonychophora 



ARTHROPODA 



arthropods 



MEROSTOMATA 



Xiphosura 



Xiphosurida horseshoe-crabs 

 PYCNOGONIDA sea-spiders 

 Eupantopoda 



