Memory alpha cultural institute

The era's name on an LCARS display

The Arnold Era was a cultural period on the planet Tagus III. Artifacts found in the ruins dating to this period were recovered by the Speckman and Sordal-Palka Excavations of the American Continent Institute. These excavations occurred prior to the sealing of those ruins by the Taguan government in the mid-23rd century. (TNG: "Qpid")

Information on this period is from an okudagram titled Tagus III Archaeological Notes which was perused by Captain Jean-Luc Picard in 2367. The name of the second excavation is not fully legible.
It was named after research consultant Richard Arnold.