We kind of knew this one was coming. From the DMN blog:
The Cowboys have signed nose tackle Remi Ayodele to their 53-man roster Tuesday and placed Jason Ferguson on injured reserve.
Ferguson suffered a torn right biceps in Sunday's season opener vs. the New York Giants and will have surgery on Friday. Ayodele, the younger brother of linebacker Akin, was among the Cowboys' final cuts coming out of training camp.
The Cowboys hoped to put him on the practice squad, but he was claimed by Atlanta. The Falcons released Ayodele over the weekend, giving the Cowboys a chance to re-sign Ayodele.