Postmetamorphic ontogenetic allometry and the evolution of skull shape in Nest‐building frogs Leptodactylus (Anura: Leptodactylidae)

DUPORT?BRU, ANA S.; PONSSA, MARÍA L.; VERA CANDIOTI, FLORENCIA

EVOLUTION & DEVELOPMENT

WILEY-BLACKWELL PUBLISHING, INC

Año: 2019 vol. 21 p. 265 - 277

1520-541X

Allometry constitutes an important source of morphological variation.However, its influence in head development in anurans has been poorlyexplored. By using geometric morphometrics followed by statistical andcomparative methods we analyzed patterns of allometric change during cranialpostmetamorphic ontogeny in species of Nest‐building frogs Leptodactylus(Leptodactylidae). We found that the anuran skull is not a static structure, andallometry plays an important role in defining its shape in this group. Similar to other groups with biphasic life‐cycle, and following a general trend invertebrates, ontogenetic changes mostly involve rearrangement in rostral,otoccipital, and suspensorium regions. Ontogenetic transformations areparalleled by shape changes associated with evolutionary change in size, suchthat the skulls of species of different intrageneric groups are scaled to eachother, and small and large species show patterns of paedomorphic/peramorphicfeatures, respectively. Allometric trajectories producing those phenotypes arehighly evolvable though, with shape change direction and magnitude varyingwidely among clades, and irrespective of changes in absolute body size. Theseresults reinforce the importance of large‐scale comparisons of growth patternsto understand the plasticity, evolution, and polarity of morphological changes in different clades.