Burrowing behavior of Dermatonotus muelleri (Anura,Microhylidae) with reference to the origin of the burrowing behavior of Anura

Dermatonotus muelleri is a forelimbs-head-first burrowing frog that uses its forelimbs for soil removal, and it is the second anuran species known to arch its head downwards at an angle of almost 90° to the longitudinal axis of its body when burrowing. The burrowing behavior of D. muelleri is divided in three stages: head burrowing, body burrowing, and chamber construction. Burrowing in D. muelleri includes construction of a subterranean chamber used for estivation during the dry season. Phylogenetic analysis based on literature survey of burrowing behavior suggested that head-first burrowing behavior has evolved several times in anuran history, forming a convergence complex, and that hindlimbs-first burrowing is a basal behavior.