Featured Old Mirror. Roman Dolphins?

They're classical dolphins like the ones on the Embankment lamp posts in London.

Debora

 

Those lamp dolphins are sturgeons.

http://footprintsoflondon.com/2015/04/here-be-dolphins-or-sturgeons/

I do agree that the mirror ones look more like sea serpents.

 

roman dolfins...ben-hur

 

Sorry I am late to the party. Circa 1900 Late Victorian Golden Oak period entry hall mirror or, possibly, the top of a hall tree/bench. Undoubtedly American. The dolphins were a common motif at the time and their presence would indicate a bit more expensive piece. Most companies made several models of similar items with the higher embellished pieces commanding more money. Consequently, you will find a lot more pieces without the embellishments seen here than with. Never would have been gilt or painted. The center piece at the top may have had fancy quartersawn veneer at one point.