I think it was clear, but just in case: not saying in the previous post that Gygax invented the idea of cave-dwelling reptilian humanoids—there were certainly precedents in fiction and myth for such creatures—just that he seems to have been the first to apply the word troglodyte to them. It’s not a super leap, since the word primarily refers to a cave-dwelling person (whether literally or metaphorically) and the original Greek means “hole-goer,” but it’s pretty significant, judging by its subsequent influence alone. (There was a nice little report on the etymology at Grammarphobia.)
One of my favorite weekend morning treats as a kid was the Land of the Lost TV show (it was in syndication by the time I was watching it). The show ran from 1974–1976 and I have to wonder how much of an influence the Sleestak were on Gygax’s original troglodite. The Sleestak’s insect-like features are removed, but, for instance, the spines on the original troglodite head look similar to the Sleestak with its horn. They are extremely hostile to humans, just like the D&D troglodytes, and while they might not carry a “revulsion odor” they sure do sound like they stink. What’s more, the Sleestak live underground in the caverns of the Lost City, which, if nothing else, is semantically similar to the Lost Caverns of Tsojconth.