While doing some work on my site I noticed that when not logged in, my "recently modified items" portlet was no longer visible. Then I realized the "edit" permission in the toolbar now was gone. Nothing that I'd done earlier seemed unusual to me, (but I had been looking at the Dexterity Content Types setup I had created a new type out of the page type, I didn't think I had modified the old ones but it appears I did, or perhaps something else modified them programmatically)
So- I didnt think I had done any saving but now I notice the only Dexterity content type that is showing up in Site Setup is the one "Citation" I had made earlier, the existing Dexterity content types are gone in the control panel but they are still there in the ZMI.
Serves me right for trying to do work on my site when I was sleepy.
gradually learning and eliminating possibilities.