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This illustration by Larry Elmore is from a fairly obscure product, the manual for the 1982 adaptation of TSR's boardgame DUNGEON! for the Apple II+. It's on the last page, and is the only illustration in the manual other than the cover, which shows a B&W version of the box cover art by Jeff Easley. It may have appeared in another TSR product, but a Google Image search didn't turn anything up.
While much smaller --- perhaps a Sub-adult? --- Easley's dragon clearly shares many details with David Sutherland's Red Dragon on the cover of the Holmes Basic Set (July 1977), particularly the head - triangular, heavy brow, cheek "whiskers". Also note the V-shaped scales down the ventral portion of the neck, the slightly curved spikes down the back, even the shapes of the scales.
Which was redone in color by Jim Roslof for the AD&D Monster Cards (1981) ---
A Red Dragon does appear as one of the monsters in Dungeon!, so Elmore may have been using one of these as a guide in order keep the look consistent between TSR products.
If you'd like to see the entire game manual, it can be found here at the Museum of Computer Adventure Game History.
You can also watch a 10-minute play-through of the game here --- Dungeon! for the Apple II
It had graphics like this screenshot, showing a Superhero versus a jolly Purple Worm ---
Update: As pointed out by John L in the comments, here is Bill Willingham's take on a similarly styled dragon, from the Moldvay Basic Set rulebook (1981).