Although my specimens meet the general description of Caloplaca inconnexa given in the 2nd reference from my previous comment, except for the coloration of apothecia (my specimens are darker than the bright orange mentioned there), I’m not sure that this is the species. On the other hand, a salient fact of microscopy, visible in all sections that I made, is that the hymenium (at least its central part) is quite dark, contrasting with much of the genus Caloplaca species I have observed microscopically. Furthermore, the paraphyses present a dark brown coloration at the apex, which is swollen. These details are not mentioned (and maybe they should not) in the general description above. The spores are within the specified values ​​for Caloplaca inconnexa, for getting the following values (including some young ones):
(10.3) 11.1 – 13.6 (14.5) x (4.9) 5.2 – 6.46 (6.5) µm
Q = (1.7) 1.9 – 2.4 (2.6); N = 20; Me = 12.2 × 5.7 µm; Qe = 2.1.
Since microscopy images obtained are bad I chose to attach only images of apothecial sections.

I found a species which is known to live parasitic on Aspicilia calcarea: Caloplaca inconnexa. Some examples are availlable at the following links:

http://mycologie.catalogne.free.fr/lichens.htm#C [choose one of the four photos of Caloplaca inconnexa]
http://www.afl-lichenologie.fr/... [A description is also available]
http://www.biodiversidadvirtual.org/...

It seems that such species is a potential candidate for this observation. Fortunately, I have a sample of the specimen in the first photo and I will analyze it as soon as possible.