Fig. 12
From: Developmental changes and novelties in ceratophryid frogs
Simplified representation of the variation in the hyoid skeleton and hyoglossal muscles in Ceratophryidae. a–d The hyoid skeleton lacks anterolateral processes and the ossification of posteromedial processes invades the hyoid plate. a Chacophrys pierottii, b Ceratophrys cranwelli. c Lepidobtrachus llanensis and d L. laevis: Species of Lepidobatrachus have discontinuous ceratohyalia and a dorsal dermal bone that is unique among anurans [81]. e–h Variation in hyoid muscles involving the geniohyoideus, petrohyoidei posteriores, and sternohyoideus [81]. e C. pierottii and Ce. cranwelli present the muscle geniohyoideus divided in partes medialis and lateralis, three pairs of muscles petrohyoidei posteriores and the muscle sternohyoideus with the partes dorsalis and ventralis completely separated. This pattern of musculature is similar to that of other hyloids. f. L. llanensis. The pars lateralis of muscle geniohyoideus has few fibers, the anterior pair of muscle petrohyoideus is absent, and partes dorsalis and ventralis of muscle sternohyoidus have shared fibers. g L. laevis. The pars lateralis of muscle geniohyoideus is absent, and the origin of the pars ventralis of the muscle sternohyoideus is displaced anteriorly. h–j Variation in the genioglossus and hyoglossus tongue musculature [81]. h C. pierottii and Ce. cranwelli show a pattern in which medial fibers of the left and right muscle hyoglossus converge to form as a single muscle that penetrates into the tongue; and the muscle genioglossus bears two components: the muscle genioglossus ventralis that forms a solid structure and the interdigitated component, which has fibers radiating caudally from their origin on the mandible. i L. llanensis. j L. laevis. In Lepidobatrachus spp., the medial fibers of each muscle hyoglossus remain separate and each muscle hyoglossus conserves its autonomy. The muscle genioglossus is formed only by interdigitated components that have few divisions and loose fibers. Furthermore, the tongue in Lepidobatrachus is smaller than in the other genera