Most similar to Mecyclothorax ballioides Perrault, based on: 1, glabrous, well-indicated pronotal hind angle and briefly sinuate basolateral pronotal margin; 2, presence of only the apical elytral seta, the subapical seta associated with the seventh stria absent. However, this species is characterized by presence of only the posterior supraorbital seta, resulting in a setal formula of 1121. The pronotal base is also much broader than in Mecyclothorax ballioides, with MPW/BPW = 1.33–1.36 (n = 2), versus 1.58–1.73 (n = 5) for Mecyclothorax ballioides. Standardized body length 4.1 mm. (Liebherr, 2012).
The holotype was collected in a pyrethrin fog sample of moss-covered Metrosideros trunks that served as nursery logs for Melicope plants. This specimen plus the holotype of Mecyclothorax putaputa comprised the entirety of carabid beetles from that sampled trunk. The female allotype was collected by beating Myrsine and mossy vegetation in the same area of low-stature forest, the allotype syntopic with two specimens of Mecyclothorax anaana. (Liebherr, 2012).