Origin
There are several theories about the term's origin. One theory revolves around people finding groups of elephant skeletons together, or observing old elephants and skeletons in the same habitat as Kenneth Armitage suggests. Others such as Enrico Bruhl suggest that the term may spring from group die-offs such as one he excavated in Saxony-Anhalt which had 27 Palaeoloxodon antiquus skeletons. In that particular case the tusks of the skeletons were missing, which indicates either that hunters killed a group of elephants in one spot, or else that opportunistic scavengers removed the tusks from a natural die-off.
Other theories focus on elephant behavior during lean times, suggesting that starving elephants gather in places where finding food is easier, and subsequently die there. Similarly, Rupert Sheldrake notes that elephant skeletons are frequently found in groups near permanent sources of water and suggests that elephants suffering from malnutrition instinctively seek out sources of water in the hopes of improving their condition. The elephants that do not improve develop increasingly low blood sugar, slip into a coma and die. Finally, older elephants whose teeth have worn out (typically after their sixth set of teeth) seek out soft water plants and eventually die near watering holes.
The myth was popularised in films such as Trader Horn and MGM's Tarzan talkies, in which groups of greedy explorers attempt to locate the elephants' graveyard, on the fictional Mutia Escarpment, in search of its riches of ivory. More recently, Walt Disney's The Lion King referred to the motif.