Mitrate

The organisms were a few millimetres long. However, they do not display the familiar fivefold symmetry that more recent echinoderms possess, instead being close to (but not fully) bilaterally symmetrical. Their heads had two sides; one, flat, was covered with large "pavement-like" a character lost in other echinoderms but present in hemichordates. This caused R. P. S. Jefferies to hold them as the ancestor of all chordates, a theory that has since been disproven. ==Behaviour==

The mitrate Rhenocystis latipedunculata has been found with associated trace fossils. Their interpretation requires an understanding of how the animal was oriented in life; it's not agreed whether the convex side of the head was up or down, or indeed whether the "tail" was at the front or back of the organism. The trace fossils suggest that they pulled themselves through the mud with their "tail", and were flat-side up. == Taxa ==

The following taxa are recognized as being included in the Mitrata as of a 2002 review of the order: • Adoketocarpus • Allanicytidium • Anatifopsis • Anomalocystites • Aspidocarpus • Ateleocystites • Australocystis • Balanocystites • Barrandeocarpus • Bokkeveldia • Chauvelia • Chinianocarpos • Dalejocystis • Diamphidiocystis • Enoploura • Eumitrocystella • Guichenocarpos • Jaekelocarpus • Kierocystis • Kopficystis • Lagynocystis • Milonicystis • Mitrocystella • Mitrocystites • Mongolocarpos • Notocarpos • Occultocystis • Ovocarpus • Paranacystis • Peltocystis • Placocystella • Placocystites • Protocytidium • Pseudovictoriacystis • Rhenocystis • Spermacystis • Tasmanicytidium • Victoriacystis • Vizcainocarpus • Willmanocystis • Yachalicystis ==References==