Fig. 4. Oral papillae sensu lato. A in Interactive identification key to all brittle star families (Echinodermata; Ophiuroidea) leads to revised morphological descriptions

Fig. 4. Oral papillae sensu lato. A. Ventral side of a schematic brittle star. B. One angle of the oral frame includes a dental plate (DP), two oral plates (= half-jaws) (OP), two adoral shields (AdSh), and one oral shield (OSh), positioned from proximal towards distal. The typical position of teeth, tooth papillae, secondary infradental papillae (2IPa), infradental papillae (IPa), buccal scale, secondary adoral shield spine (2AdShSp), adoral shield spine (AdShSp) on DP, OP and AdSh are illustrated, respectively. The presence / absence, number and shape of each papilla vary among different taxa.