This usually comprises a short radial tunnel leading to a single, large, flat brood chamber, extending in the longitudinal plane.
Previous morphological studies of Amasa have suggested that species are very morphologically variable (Hulcr and Cognato 2013). As a result many species were considered conspecific and part of a morphological continuum. Molecular data generated as part of this study has demonstrated that Amasa species are actually morphologically conserved even across broad ranges (Smith et al. 2020a). Amasa species outside of our coverage area are thus in need of revision, and potentially much of the diversity is awaiting discovery.