Fossils of isolated land plant spores (Heckman et al, 2001) suggest land plants may have been around as long as 475 million years ago; Fossils of land plant spores within plant fragments (Wellman et al., 2003) date back to 425 million years ago ( these were found in Oman and appear to be liverwort-like, although elaters are noticeably absent!)
The noun PUPILLARY REFLEX has 1 sense: 1. reflex contraction of the sphincter muscle of the iris in response to a bright light (or certain drugs) causing the pupil to become smaller. Familiarity information: PUPILLARY REFLEX used as a noun is very rare. Dictionary entry details.
The pigmented area around the pupil is the iris. Along with supplying a person's eye color, the iris is responsible for acting as the pupil's stop, or sphincter. Two layers of iris muscles contract or dilate the pupil to change the amount of light that enters the eye. Behind the pupil is the lens, which is similar in shape and function to a camera lens.