Input (grade 13): Early Cambrian forms like Helcionella and Scenella are no longer considered gastropods, and the tiny coiled Aldanella of earliest Cambrian time is probably not even a mollusk.
Output (grade 10): Early Cambrian forms like Helcionella and Scenella are no longer considered gastropods. The tiny coiled Aldanella of earliest Cambrian time is probably not even a mollusc.