Myrmecorhynchus André

Shattuck, S. O., 2015, A review of the ant genus Myrmecorhynchus (Hymenoptera: Formicidae), Zootaxa 3955 (2), pp. 283-290 : 283

Myrmecorhynchus André

Myrmecorhynchus André, 1896: 253 . Type-species: Myrmecorhynchus emeryi , by monotypy.

Diagnosis. Mandibles usually with 10 to 13 teeth, although some large individuals with as few as 6. Frontal carinae distinctly arched. Upper surface of mesosoma between metanotum and propodeum always low and flat or concave and never expanded upwards. Worker caste variable in size (strongly polymorphic) with distinct major and minor workers.

Smaller workers of Myrmecorhynchus are identifiable by the large number of mandibular teeth. However larger workers have a reduced number of teeth (down to 6 in some individuals) and are similar to some species of Notoncus . These individuals can be identified by the configuration of the frontal carinae (curved in Myrmecorhynchus , straight in Notoncus ) and the polymorphic worker caste with distinct majors and minors ( Notoncus is weakly polymorphic and without distinct majors and minors). Additionally, some species of Notoncus have an upwards projection on the upper surface of the mesosoma at the metanotal groove. This region of the mesosoma is always flat or concave in Myrmecorhynchus .