A PM overwrote a project templete. Project server is being backed up several different ways. When a project template is saved as an Enterprise Template, where is it located?
If you don't have the administrative backup enabled as Barbara suggests, then they live in the DRAFT database as far as I know, so you would be looking at a instance restore, or perhaps a restore to a VM and extract them from there.
For future reference, I tend to advise customers to also keep a copy of the templates in a document library on the PWA site should they run into the exact same issue you have.
Thank you Barbara and Alex. Admin backup is scheduled, however it has not been running. Luckily it was a small template that can be quickly recreated. I'll add the admin backup to a growing checklist of items for daily review.