Zoids was Tomy's 1983 U.S. relaunch of an earlier Japanese line of wind up prehistoric themed robot models named Mechabonica. I've found ads for most of the assortments in the original line in newspapers from 1983 with the exception of the Radio Shack exclusive Mammoth, which I've only found one ad for from 1985. There is a conspicuous absence of Zoid advertising in 1984 leading me to believe it may have been put on hiatus while Tomy concentrated on its Starriors line of more traditionaly humanoid yet still very Zoidish action figures. Then in 1985 Tomy launched Robo Strux, a line of models similar to Zoids in that they were again based on prehistoric animals but not as skeletal. While Robo Strux enjoyed more retailer advertising than Zoids got, it was still overshadowed by more popular toy robot lines of the day and ads for Robo Strux are rather uncommon. Most of the newsprint advertising for the line was split between the largest robot, Terox, and the smallest kit assortments. Ads for intermediate Robo Strux like the Gordox and Brutox are relatively rare. The bulk of Robo Strux advertising exists during 1985 but becomes scare in 1986 and nonexistant thereafter.