The stylophorans are an extinct group allied to the echinoderms, comprising the cornutes and mitrates. It is synonymous with
the subphylum Calcichordata. Its members have a shell like an echinoderm's. Some say that all or some of its members have
gill slits like a chordate, and that its stem contained a notochord. In Mitrocystites and perhaps in other forms its stem
does not end in an attachment organ, and the stem likelier served it as a tail for moving itself about by.
