Key to Australian Cardiocondyla Species

1

 * Protonum with distinct humeral angles => Cardiocondyla thoracica


 * Pronotum uniformly rounded anterolaterally => 2

2

 * Metanotal groove weakly developed or absent => Cardiocondyla nuda and Cardiocondyla atalanta (See Note below)


 * Metanotal groove distinct in lateral view => 3

3

 * When viewed in lateral profile, posterior mesonotum sloping gradually into metanotal groove through a uniform curve; petiole node in dorsal view generally distinctly longer than broad; head relatively narrow (CI 72-79) => Cardiocondyla emeryi


 * When viewed in lateral profile, posterior mesonotum changing slope abruptly and curving steeply into the metanotal groove; petiole node in dorsal view generally slightly broader than long; head relatively broad (CI 79-86) => Cardiocondyla wroughtonii

Note
C. atalanta was synonymised with C. nuda by Taylor (1991 ). Seifert (2003 ) removed C. atalanta from synonymy and considered it to be represented by types only, the remaining Australian material belonging to C. nuda. More recently, Seifert (2008 ) modified his concept of C. atalanta to include essentially all Australian material and found only a few specimens which belonged to C. nuda. Unfortunately he could not find any readily observable characters to separate these two taxa with recognition being based on statistical differences in the length of pilosity hairs on the first gastral tergite. Thus separation of these cryptic species is not possible using a simple morphology-based key such as this and identification will require more advanced morphometric procedures such as detailed by Seifert (2008 ).