The following key to Myrmecorhynchus workers is based on Shattuck (2015).
- Mesosomal dorsum and legs with abundant erect hairs => Myrmecorhynchus emeryi
- Mesosomal dorsum with at most a few scattered erect hairs, legs with appressed pubescence but lacking erect hairs => 2
- Extensive yellow on clypeus covering at least 1/3 of surface; mandibles completely yellow (except dark teeth) => Myrmecorhynchus nitidus
- Clypeus generally completely dark, at most with a narrow band of yellow on anterolateral margin; mandibles bicoloured, yellow basally and dark apically => Myrmecorhynchus carteri