 Their function was to assist the trilobite in shedding its old exoskeleton during ecdysis (or molting).All species assigned to the suborder Olenellina, that became extinct at the very end of the Early Cambrian (like "Fallotaspis", "Nevadia", "Judomia", and "Olenellus") lacked facial sutures.They are believed to have never developed facial sutures, having pre-dated their evolution.