The heavenly realm, or firmasphere, was populated on the fourth day. Zechariah describes one heavenly being as a woman with the wings of a stork. This means that women existed in heaven before there were women on Earth.
Seraphim and Cherubim were created in the firmasphere on the 4th day. God recombined their characteristics as he created the moving creatures in the hydrosphere and fowls in the atmosphere on the 5th day.
Can we take a systematic approach to the Bible and come to know the mind of Christ? Some things are spiritually discerned, but if we who are spiritual take a systematic approach, what will we find?
Artistic renderings of Seraphim consistently miss the fact that they're reptilian. Their physical characteristics will have implications for us when we consider the terrestrial serpents that were created on the sixth day.