Have you considered having the previous explorer die far enough in the past to allow his bones to be picked clean? There are a variety of fantasy skeletons available for genres such as pirates and ancient Egypt. Could modify these by putting on a pith helmet and draping some torn clothing over the figure using thin paper and white glue. Reaper has quite a few skeletons available.
Quite valid point. My thinking is that rotted flesh would better qualify as Horrific than cleanly picked bones. The Pulp Alley Horror rules suggest "searching a pile of rotting corpses" as a Horrific plot point, for example. A dismembered corpse with its head on a stake, surrounded perhaps with totems (skulls-on-a-stick
a la those shone in the
Congo rulebook, mayhaps?) or the like is where I'm leaning at the moment.
The Lost World scenario at the moment includes a Neanderthal male-only tribe who has kidnapped the deceased explorers' daughter, two tribes of rival Amazons (Warlord/Lucid Eye), a party of explorers [trying to find the ex-explorer and daughter], and a League of Sky Pirates (Statuesque). Major plot point will be the captured daughter (from Pulp Figures Cringing Captives), and minor plot points will be a nest of eggs from a large carnivorous flightless bird (Reaper Axebeak), the rotting corpse (above), something-or-other to be found in the cave of a cave bear (DeeZee), and a plot-point-or-two-to-be determined-later. Also running around out there will be a Reaper sabre-toothed tiger and some alligators in the river. And maybe a carnivorous plant (Antediluvian Miniatures)?
Any similarity to Tarzan's Opar [ape men, normal women] is entirely intentional.

Now that I think about it, I'll need skeletons and bones for the bear cave, so suggestions there are welcome.