The Dropa Stones Part II-The Mysterious Graves

Along with the discs found at in the caves in the isolated mountain in China, there were graves found. The graves found at the drop Caves in China contained a specimen of an unknown species. It were thought to be an undiscovered species or extinct breed of ape, but was rules out when the remains were actually buried.
The specimens inside were only about four feet tall with oversized heads. Very similar to what UFO researchers refer to as "Grays."
Also there were painting found inside depicting some type of species wearing helmets.
A legend in China by the local inhabitants stated that a mysterious race of beings crash landed on in mysterious ship. The referred to themselves as the "drop."
The legend had stated that these beings crash landed in their space ship near the isolated mountains along the China/Tibet border nearly twelve thousand years ago. It was reported that the beings were gaunt and thin. They had Yellow faces and only about four feet tall, according to accounts.

Who were these "beings" found in the graves? Were they truly of a extraterrestrial origin? Did humans actually have contact with these beings 12,000 years ago? Did they really come from a different planet? Is there a possible explanation to the mysterious graves found in the caves? If so, who and what were these beings? Were they in fact a terrestrial human race that is now extinct? Are they an unknown species of ape?
One thing is for sure it has many unexplained circumstances surrounding the mystery. A mystery that may always haunt us with one question, what really happened in that area of China 12,000 years ago?