Table 1 Statistical tests of alternative phylogenetic hypotheses

Unconstrained tree

154,788

0.96

Phylogenetic position of Pipoidea within Anura

Pipoidea branching before Discoglossoidea

154,827

0.001

Pipoidea + Pelobatoidea

154,836

<0.001

Pipoidea + Discoglossoidea

154,822

0.003

Monophyly of Archaeobatrachia

154,870

<0.001

Internal relationships within Pipidae

(Xenopus + (Silurana + (Pipa + (Hymenochirus + Pseudhymenochirus))))

155,353

<0.001

((Pipa + Hymenochirus) + (Xenopus + Silurana))

154,807

0.089

Pseudhymenochirus basal in Pipidae

155,07

0.021

(Pseudhymenochirus + Hymenochirus) basal in Pipidae

154,814

<0.001