The concept of Ardhanarishvara originated in Kushan and Greek cultures simultaneously; the iconography evolved in the Kushan era (30–375 CE), but was perfected in the Gupta era (320-600 CE). A mid-first century Kushan era stela in the Mathura Museum has a half-male, half-female image, along with three other figures identified with Vishnu, Gaja Lakshmi and Kubera. The male half is ithyphallic or with an "urdhvalinga" and makes an "abhaya mudra" gesture; the female left half holds a mirror and has a rounded breast. This is the earliest representation of Ardhanarishvara, universally recognized. An early Kushan Ardhanarishvara head discovered at Rajghat is displayed at the Mathura Museum. The right male half has matted hair with a skull and crescent moon; the left female half has well-combed hair decorated with flowers and wears a patra-kundala (earring). The face has a common third eye. A terracotta seal discovered in Vaishali has half-man, half-woman features. Early Kushan images show Ardhanarishvara in a simple two-armed form, but later texts and sculptures depict a more complex iconography.