Cartilage element on the neurocranium of sawsharks and batoids, separate cartilages attached to the sides of the nasal capsules that support the sides or front of the head. [Compagno, L.J.V. Sharks of the world. An annotated and illustrated catalogue of shark species known to date. Volume 2. Bullhead, mackerel and carpet sharks (Heterodontiformes, Lamniformes and Orectolobiformes). FAO Species Catalogue for Fishery Purposes. No. 1, Vol. 2. Rome, FAO. 2001. 269p. ISBN 92-5-104543-7]. [ https://www.worldcat.org/search?q=bn%3A92-5-104543-7 ]