Fig. 10

Ceratophyrid fangs in whole mounts stained for cartilage and bone, and in living specimens. a Lower jaw of a recent metamorphosed Lepidobatrachus llanensis in which the cartilaginous mandibular symphysis and pointed fangs are shown, bar is equal 1 mm. b Lingual view of the mandibular symphysis in Ceratophrys cranwelli. The fangs are stout, the mandibular bones are strongly fused, and the mentomeckelian elements are not visible; bar is equal 1 mm. c Ventral view of the lower jaw in a metamorphic specimen of L. laevis. The image shows the fang germs located in the lingual face of the lower jaw adjacent to the infrarostral cartilage. Calcification of the fangs precedes the calcification of lower jaw bones. d Detail of the fang germs in the specimen in c, bar is equal 5 mm. e Frontal view of the fangs with an integumentary cover in an adult specimen of L. laevis. f The fangs and the serrated teeth suggest powerful jaws to hold and subdue prey in adult of L. laevis. The development of fangs arising from the lower jaw in these frogs necessitated changes in the premaxillary and maxillary bones. When the mouth is closed, the fangs rest in the superficial lingual part of the alar process of the premaxillary as the palatal shelf of the premaxillary is absent in horned frogs [2, 25]