fenestral

This fenestral architecture has been seen in ancient archosaurs, but not in other pachycephalosaurs.

Mammals, which are synapsids, possess no fenestral openings in the skull, as the trait has been modified.

Grade 3, diffuse confluent cochlear involvement (with or without fenestral involvement).

The fenestral discovery, incidentally, also filled in a missing link to provide a 300 million year sequence of fossils showing a smooth evolution from reptiles to mammals.

Or we can if we like we can close the shutter at night at Summer nights, But in the Winter if we want to have some light, we open the shutter and put the fenestral back again, either way round it doesn't really matter.