The tapetum lucidum is found in Ungulata, Cetacea and Carnivora.
Iris tapetum: the pigment layer of the compound eye just below the crystalline cone.
The subject, however, of the various colours of the tapetum in different animals is not yet understood.
1713, from Medieval Latin tapetum, from Latin tapete "carpet."
tapetum ta·pe·tum (tə-pē'təm)
n. pl. ta·pe·ta (-tə)
A membranous layer or region, especially the iridescent membrane of the choroid of certain mammals.
A layer of fibers of the corpus callosum forming the roof of part of the lateral ventricle of the brain.