A chapel of the first Roman Christians?

ARAMAIC WATCH: Roman Christians’ first church found in Diyarbakır, southeast Turkey. Excavations at the ancient Roman military outpost of Zerzevan Castle in the Çınar district of Turkey’s southeastern province of Diyarbakır have uncovered a chapel belonging to the very first Romans who converted to Christianity (BGNNews.com).

“We can say it’s the first place of worship from when the Romans transitioned from polytheism to Christianity,” Dicle University Archeology Faculty Assistant Professor Aytaç Coşkun said referring to the recently uncovered underground chapel in Diyarbakır’s Zerzevan Castle.

Pointing out that they discovered several crosses as well as Aramaic script on the chapel’s walls, Coşkun says they have invited an Aramaic expert to decipher the writing.

“It seems they also made a baptismal pool out of the parent rock,” Coşkun added. “It is a rather large baptismal pool. Since the first converts to Christianity were older, they built a large baptismal pool outside.”

“This chapel was built when the number of Christian converts rose,” he said. “A larger church where soldiers and civilians could all worship was built on the same spot about 150 years later.”

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I don't know what the evidence is for the extraordinary claim made in the first sentence of this article, but I am skeptical. It does not help that no absolute date for the earlier discoveries is given, or for the church that was built "about 150 years later." The end of the article does specify that the castle was still in use up to 639 CE, but that doesn't clarify the dates of the earlier discoveries. But in any case, I would like to hear more about the Aramaic inscriptions (if that's what they are) on the walls of the underground chapel.