Assertion: echinoderm's organ | /r/CapableOf | develop in the nephrozoa
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Source sentences:
text: The acoelomorph taxa had previously been considered flatworms with secondarily lost characteristics, but the new relationship suggested that the simple acoelomate worm form was the original bilaterian bodyplan and that the coelom, the digestive tract, excretory organs, and nerve cords developed in the Nephrozoa.