https://phys.org/news/2020-07-scientists-fossil-early-stages-owl.html
Moreover, the new discovery reveals a high level of diversity among the owls of the early Eocene in North America—from the small species Eostrix gulottai, measuring a mere 12 centimeters, to the newly discovered, roughly 60-centimeter-tall bird.
Your post yesterday inspired me to dig a little more into owls of the past, thanks.
I remember reading something about their skulls being extremely fragile. I'll try to find the source.