>>40608855akshually !!! polychaete worms are annelids while velvet worms are close to arthropods, hallucigenia is on the arthropod line so its fairly close to velvet worms but polychaetes are outside that branch entirely
lots of famous cambrian invertebrates are part of the not-quite-arthropod evolutionary line, like anomalocaris & opabinia, though theyre more distant from velvet worms than hallucigenia was. though i think some ppl in the field might actually consider opabinia to be within the "lobopodian" group alongside hallucigenia
picrel is a reconstruction of omnidens by @prehistorica_cm. it's only known from fossil mouthparts but based on those it's thought to be a very close relative of pambdelurion, which looked somewhat like the image except omnidens wouldve been much much bigger