Molecular perspectives on the phylogenetic affinities of lyrebirds (Menuridae) and treecreepers (Climacteridae)

Within the Australo-Papuan region, DNA-DNA hybridisation studies revealed a major radiation among the oscine songbirds. Although many of the relationships revealed have been corroborated by other molecular evidence, the apparent relationship between lyrebirds, treecreepers and bowerbirds remains controversial. To examine this issue, a 924-bp fragment of the cytochrome-b gene was sequenced from a lyrebird and treecreeper and compared with published sequences of other Australo-Papuan songbirds. Despite possessing several distinctive morphological features, lyrebirds and treecreepers are part of the oscine assemblage. Although less conclusive, the cytochrome-b data also provide some support for a grouping of lyrebirds with treecreepers. These may also be linked with honeyeaters or bowerbirds. On the basis of current molecular evidence, the Australo-Papuan songbird radiation is clearly the most divergent oscine assemblage in terms of morphological adaptations.