This example of the common 𝘈𝘳𝘵𝘦𝘦𝘣𝘶𝘴 𝘕𝘢𝘺𝘴𝘮𝘪𝘵𝘩 is an evolutionary throwback; she has a single-lens visor rather than the archetypal two. This atavism from the basal form 𝘈𝘳𝘵𝘦𝘦𝘣𝘶𝘴 𝘓𝘦𝘦𝘵𝘰 gradually vanished from the fossil record, until it become completely absent with the rise of 𝘎𝘰𝘰𝘥𝘸𝘪𝘯𝘪𝘶𝘴