It was originally placed in the genus Aphaenogaster, but a recent phylogenetic study concluded that it is genetically distinct and should be separated.

Novomessor albisetosus was originally identified by Austrian entomologist Gustav Mayr in 1886, who first described the species as Aphaenogaster albisetosa.

Brown notes that the characters supposed to distinguish the two genera are not strong enough when one considers the global fauna of this complex.

Engel revived the genus in 1976 on the basis that N. albisetosus and N. cockerelli had an exocrine gastral glandular system that was not found in any examined Aphaenogaster ant.

[8] In 1982, English myrmecologist Barry Bolton argued that basing the genus on such a feature could not justify the separation of Novomessor and Aphaenogaster.

Cognato concluded that Novomessor was genetically distinct from Aphaenogaster, and the genus was revived from synonymy with N. albisetosus as one of the three known species.

Morphologically, the promesonatal suture and the postpetiole are diagnostic for Novomessor ants and the three species share a closer relation with Veromessor than Aphaenogaster.

[2][12] The body color of the ant is ferruginous (rust-colored), the legs are reddish brown and the petiole (the waist) and abdomen are brownish black.

The antennae are small with three sensilla (sensory receptors), and the labrum (a flap-like structure that lies immediately in front of the mouth) is short.

Both species share a similarly structured thorax, but the epinotal spines in N. albisetosus are just as long as the basal face of the epinotum (the dorsal aspect of the pronotum).

Males of N. cockerelli are smaller, measuring 6 millimeters (0.2 in) and have short heads, and the mesonotum is covered with weak rugosities.

Both ants are found on the eastern side of the Sierra Madre Occidental until the topography changes in northwestern Chihuahua.

Up north, the Sierra Madre Occidental breaks up into a number of ranges that communicate on the east of the Mexican Plateau, and, to the west, with the narrow Sonoran coastal plain where N. albisetosus and N. cockerelli are abundant.

The northern limit is mostly determined by its inability to survive in highland areas in central Arizona and New Mexico.

These entrances are roughly constructed and descend steeply into the ground, appearing more like a rat's burrow than an ant's nest.

Despite being previously known as individual foragers, N. albisetosus will recruit others when handling large prey items to carry them back to the nest in a cooperative manner.

[12] Workers stridulate (produce sound by rubbing together certain body parts) when pieces of food they have found are too large to carry back.

[25] Adult workers are considered mature when they spend more than half of their time outside rather than remaining inside the nest tending to the young.

These matured adults (excluding the oldest ones) will revert to tending the brood and queen when almost all age groups are removed from the nest.