They’re like birds, right? Don’t they have a cloaca instead?
searches
Apparently yes, though this author couldn’t resist “butthole”…
https://www.livescience.com/first-dinosaur-butthole-found.html
1st preserved dinosaur butthole is ‘perfect’ and ‘unique,’ paleontologist says
This was a multipurpose hole.
The first dinosaur butthole ever discovered is shedding light where the sun don’t shine. The discovery reveals how dinosaurs used this multipurpose opening — scientifically known as a cloacal vent — for pooping, peeing, breeding and egg laying.










OP did say that it was inside his garage. I mean, in all honesty, most buildings are not built to be Fort Knox. If someone is intent on burglarizing them, they’re probably going to get in.