Hi Ed.
In some races of bees it is common to find multiple queens.  In the
European races, it is rare but it may happen just like you just found
out.  I have found colonies with two queens, one as recent as two months
ago when I was inspecting a colony of a friend. (My friend is also a
Bee-L subscriber and will most likely be reading this post at the same
time that you).
It would be interesting to see if the two remained together without
swarming.
Did you remove one of them, or did you allow them to stay together?
Best regards.
Dr. Rodriguez
Virginia Beach, VA