Figure 7 in Morphological evolution in Ceratophryinae frogs (Anura, Neobatrachia): the effects of heterochronic changes during larval development and metamorphosis

Figure 7. Variation in the origin of the m. suspensorioangularis in tadpoles (stage 37). A, in Chacophrys pierottii, the m. suspensorioangularis has a preorbital origin, its fibres originate at the posterior base of the process muscularis. B, in Ceratophrys cranwelli, the m. suspensorioangularis is long, and has fibres originating posterior to the base of the processus muscularis at the ventral surface of the palatoquadrate, and are covered by the m. hyoangularis. The origin of this muscle in this species is at the level of the eye. C, in Lepidobatrachus llanensis, some fibres of the m. suspensorioangularis originate from the lateral expansion of the palatoquadrati, behind the posterior base of the processus muscularis, and other fibres that are joined by connective tissue link the origin of this muscle with the ceratohyal. The origin of this muscle is postorbital. Haas (2003) recognized a posterior origin of the m. suspensorioangularis in basal anurans –differing from the preorbital origin observed in neobatrachians. Scale bars: 1 mm.