Short communicationHomology of the muscles within the uropatagium membrane in Leschenault's rousette (Rousettus leschenaultii)

Pteropodidae possess unique muscles in the uropatagium called Musculus uropatagialis and M. depressor ossis styliformis. The homology of these muscles is important for the phylogenetic analysis of bats because the wing membrane is a characteristic feature for them. Here, I discuss the homology of M. uropatagialis and M. depressor ossis styliformis in Rousettus leschenaultii by tracing their innervations. I found that the dominant nerve for the M. uropatagialis contains the components of the sciatic nerve associated with the dominant nerve of the flexor muscles of the thigh. This result shows that M. uropatagialis is homologous to the flexor muscles of the thigh. The dominant nerve of M. depressor ossis styliformis is the lateral plantar nerve derived from the tibial nerve. Thus, this innervation pattern proposes the hypothesis that M. depressor ossis styliformis is homologous to one of the muscles of the foot sole.