Captorhinus kierani was named by deBraga et al. (2019) [A single-tooth rowed small to medium-sized captorhinid characterized by three autapomorphies: 1- presence of well-developed recurved dentition on the apex of parasphenoid plate, at the base the basipterygoid processes, which is distinguishable from an absence of recurved dentition in the same region of the palate in Captorhinus aguti, 2- teeth along the jaw mid-line (tooth position 6–10) possessing a distinct anteromesial descending ridge (carina) nearly reaching the gum-line, and 3- The occiput is unique in the possession of a deep horizontally oriented sulcus extending along the exposed surface of the paired postparietals. There are additional un-polarized character traits that can be used to distinguish Captorhinus kierani from other members of the genus. These include: evidence for 21 maxillary and 18–20 dentary teeth, possession of a nearly horizontal (oriented 70° to the long axis of the skull) suture between the frontal and nasal, which distinguishes this taxon from Captorhinus magnus, where a 45° angle, relative to the skull midline, is formed between the frontal and nasal.]. It is not extant. Its type specimen is OMNH 73281a, a skull (subadult complete skull).