From Bib Arch, by Noah Wiener, about the find of Mauro Perani:
Italian scholar Mauro Perani recently discovered what he believes to be the oldest complete Torah scroll. The recently-dated Sefer Torah—a handwritten Torah scroll containing the full texts of Genesis, Exodus, Leviticus, Numbers and Deuteronomy—was written between 1155 and 1225 C.E. The monumental value of the sheepskin document went unnoticed for over a century; in 1889, it was mistakenly cataloged in the University of Bologna Library as a 17th-century Sefer Torah. While compiling a catalog of Hebrew manuscripts held at the library, Perani recognized that the script on the nearly 120-foot-long scroll was significantly older than its catalog date. Furthermore, the scroll did not follow scribal standards established at the turn of the 13th century by Maimonides, the foremost intellectual figure of medieval Judaism. The paleographic analysis was followed by carbon-14 tests at the University of Salento and the University of Illinois, Urbana-Champaign, which confirmed the 12–13th-century date.