David A. Nipperess and Andrew J. Beattie. 2004. Morphological dispersion of Rhytidoponera assemblages: the importance of spatial scale and null model. Ecology 85:2728–2736.

Appendix A. Images of the Operational Taxonomic Units (OTUs) of Rhytidoponera, Sturt National Park, Australia, and accompanying notes regarding their presumed species status.

Designation	Species-group	Image - lateral view	Image - head view
		Left-click on the image to view a higher-resolution version or right-click to download.
Rhytidoponera sp. A	metallica
Rhytidoponera sp. D	metallica
Rhytidoponera ?pilosula	convexa
Rhytidoponera sp. nr. maniae	convexa
Rhytidoponera sp. B	convexa
Rhytidoponera sp. C	mayri
Rhytidoponera sp. E	mayri

A Note on the presumed taxonomic rank of the OTUs described in this paper:

Both reviewers of the submitted manuscript of this paper expressed some concerns about the status of the OTUs described therein as "good species". Our justification for treating the OTUs as species-surrogates is based on the following points:

1. We suspect that concerns that the OTUs represent ecotypes rather than full species is based in part on the use of the term "species-group". In Australian ant taxonomy, a species-group is most definitely viewed as a superspecific clade, comprising a number of described species. Also, it seems to us that ecotypic variation is to be expected at biogeographic, rather than regional, scales. Finally, if ecotypes of a single species were present within the region, we could expect some evidence of hybridization, resulting in incomplete differentiation of the OTUs.

2. Rhytidoponera exhibits very little caste polymorphism - see Shattuck's synopsis of the genus^†

3. It is the opinion of an experienced ant taxonomist, Dr Alan Andersen, that these OTUs provisionally represent separate species.

4. The OTUs are consistently distinguishable "by eye", and also show varying degrees of differentiation in a Principal Components Analysis.

^†URL: <http://www.ento.csiro.au/science/ants/ponerinae/rhytidoponera/rhytidoponera.htm>