Figure 5

Schematic representation of the supporting elements of the linguo-laryngeal apparatus of D. novaehollandiae. Dorsal view. The cricoid and procricoid cartilages as well as the fleshy lips of the glottis are omitted for clarity. The caudal aspect of the arytenoid cartilages (Ar) are not joined as indicated but separated by the procricoid cartilage (not illustrated). However, the relative position of the protrusion of the fleshy lips (yellow star) (see Figures 1d-f, 4) have been indicated. Red indicates bone and blue/purple cartilage as seen in an 8 week-old chick. a: Resting relationship (see Figure 1d) of the arytenoid cartilages, tongue body (T), tongue root (R), urohyal (U), body of the basihyal (Bb), rostral projection of the basihyal (*), paraglossum (Pg), glottis (G) and ceratobranchials (Cb). b: The relationship of the underlying structures following retraction of the tongue (see Figure 1f). Note how the rostral portions of the arytenoid cartilages are enclosed by the tongue root and how the protrusions of the lips of the glottis and the tongue root close off the glottis.