The article states that Christians only met in private homes or in catacombs prior to 313AD, but the Edict of Milan specifically states that "churches" taken from the christians were to be returned to them. Persecution wasn't a constant factor all the time in every part of the Empire and the Edict of Milan is proof that they had been building churches and worshipping publicly. The article makes note that the apse of this church did not face East, but the practice of building churches East-West was established later, and most early churches were built with the apse facing Jerusalem (Hagia Sophia in Constantinople is a notable example). It would be interesting to know whether this church's construction followed the earlier practice.
Death toll from car bombs in Iraq rises to 56 (AP)
from the article: Prison dig reveals church that may be the oldest in the world