EVERYDAY SCIENCE

Detailed explanation-1: -An antorbital fenestra (plural: fenestrae) is an opening in the skull that is in front of the eye sockets. This skull character is largely associated with archosauriforms, first appearing during the Triassic Period. Among extant archosaurs, birds still possess antorbital fenestrae, whereas crocodylians have lost them.

Detailed explanation-2: -Temporal fenestrae are openings in the temporal region of the skull of some amniotes, behind the orbit (eye socket). These openings have historically been used to track the evolution and affinities of reptiles.

Detailed explanation-3: -The large post-temporal fenestrae (large holes in the back of the skull) of turtles allow the jaw musculature to expand beyond the confines of the adductor chamber.

Detailed explanation-4: -Anapsid reptiles are characterized by a primitive skull with no temporal openings. Turtles are the only living representatives of this clade and belong to one order variously referred to as Testudines, Testudinata, or Chelonia.