Data from: Ancestral reconstruction of reproductive traits shows no tendency toward terrestriality in Leptodactyline frogs

Background:Traditionally, the evolution of terrestrial reproduction in
anurans from ancestors that bred in water has been accepted in the
literature. Still, the existence of intermediate stages of water
dependency, such as species that lay eggs close to water (e.g., in
burrows) instead of in bodies of water, supports the hypothesis of an
ordered and gradual evolution in the direction of a more terrestrial form
of reproduction. However, this conventional view has recently been
challenged for some anurans groups. Leptodactylinae frogs are a remarkable
example of anurans with an outstanding diversity in terms of reproductive
features, with distinct water dependency among lineages. Here, we tested
the hypothesis of a gradual and ordered tendency towards terrestriality in
Leptodactylinae, including the existence of obligatory intermediate
stages, such as semi-terrestrial reproductive strategies. We also
addressed the association between reproductive modes and the morphological
and ecological features. Results: An ancestral reconstruction analysis
indicated that even though shifts from aquatic to terrestrial breeding
occurred throughout the history of Leptodactylus and Adenomera, shifts
from terrestrial to aquatic reproduction happened at almost the same
frequency. Our results also demonstrated that reproductive modes for
semi-terrestrial tadpoles were not necessarily an intermediate form
between aquatic and terrestrial breeds. Correlations among reproductive
modes and other life-history traits suggested that tadpole environment,
clutch size, nuptial spines, and egg pigmentation were co-evolving and
driven by water dependency. Conclusions: Our results found no evidence of
evolutionary tendencies toward terrestriality in Leptodactylinae. We found
reversals from terrestrial to aquatic tadpole development and no evidence
of obligatory intermediate stages, such as semi-terrestrial reproductive
strategies. We also found correlations between reproductive modes and
other life-history traits driven by water dependence. Aquatic reproductive
modes are associated with higher clutch sizes, lentic waters, and the
presence of nuptial spines and egg pigmentation.