You can see how much the D&D image/brand changed in the space of only two years. Lost Tamoachan: The Hidden Shrine of Tamoachan was the bagged (unbound) tournament module used at Origins International Game Expo (known simply as ‘Origins’) in 1979. You’ll find the complete publication history at The Acaeum. (Copies are incredibly rare.) The cover art is by David C. Sutherland III, who did the original, and best, Dungeon Master’s Guide (1979) cover.
The module was renamed upon wide release in 1980, with front and back covers by Erol Otus. Without access to color, he relied on textures—the chiseled walls, the bolt of fire, the demon’s hair, the warrior’s armor. (On the back cover, it’s the combination of trees, ancient stone, translucent scales.) The Aztec art looks damn convincing, and the shadow of the wings on the walls is the kind of detail that separates Otus from other artists.
Otus did the front cover of the 1981 edition as well. Despite the gorgeous coloring and the thicker, more abstract figures that would become his trademark style, I think I prefer the earlier, more three-dimensional work. The back cover is by Jeff Dee. He uses Otus’s template for the scene, but gives it a Marvel Comics flavor. The innocence—some would argue the purity—of early D&D art, represented by the first and second editions of Tamoachan, would never be seen again.
Read some background on the module’s development at Wizards of the Coast.
(Images via Tome of Treasures and eBay)
2 Warps to Neptune 
Looking at Erol’s artwork makes me want to do nothing more than immediately go play some D&D. After all these years, his effectiveness has not diminished.
His stuff really does belong in a museum. (I feel like Indy when I say that.) For me, his vision of D&D is the most compelling.
Agreed, he was always my favorite D&D artist from those days. His art wasn’t just medieval, it was otherworldly. It really gave the sense that this world wasn’t in Earth’s past somewhere, but in some completely different dimension.
On the other hand, I think he may have been responsible for the cover of Forgotten Temple of Tharizdun…
Nope, Tharizdun was not Otus. Whew. I can’t quite make out the signature, but it’s not his. That particular cover worked just the opposite from Otus’s effect for me back then – the artwork didn’t make me want to play at all, especially combined with the lavender color.
Ha. Beat you to it.
That was Karen Nelson. Otus did The Lost Caverns of Tsojcanth cover. I think the modules are related story-wise.
S4 was an epic cover – I can’t remember what that monster was called, but I know it had a wicked lightning attack. Yes, Tharizdun was sort of an epilogue to it.