I have found only one original source for the discovery of this skull, and this is the article that appeared in UFO Roundup *see below). It is based on a news report in the Turkish newspaper Milliyet on January 4, 2002.
The UFO Roundup article:
ALIEN SKULL DISCOVERED IN BULGARIA?
Leyla Degirmen, UFO Roundup correspondent in the Balkans, has come across a strange story in the Turkish newspaper Milliyet, which stated that an alien skull was found last May in southern Bulgaria.
“On May 21, 2001, a villager found an unusual skull on Rodolp Mountain in Bulgaria,” somewhere near Ardino and Madan, about 200 kilometers (120 miles) south of Sofia, the national capital.
“Some scientists held a meeting in Asenovgrad. Prof. Yordan Yordanov, one of the best-known anthropologists in Europe, claimed that he had never seen a human or an animal skull like this in his life. Katya Melamet, one of the archaeologists at the Bulgarian Science Academy, has also told that she has never seen anything like this.”
“The story of the villager is also very interesting,” Leyla writes, “He claimed that he had seen five people, with yellow metallic clothes, in his dream. They told the villager to go to the area on the 21st of May, and when he went there, he found the skull and a (small) elliptical metal object.”
“The skull is (weighs) about 250 grams and has six holes in it to (which apparently) belong to the senses. The skull also has no mouth hole.”
“This summary is from an article published in Milliyet on January 4, 2002.”
“I thought it is a very important discovery, but the strange thing is that I cannot find the source of this information, or any other news related to it, no matter how hard I try. Milliyet is a leading newspaper in Turkey, and they have been very reliable for over thirty years.”
Asenovgrad is a city located 100 kilometers (60 miles) southeast of Sofia, Bulgaria. (See Milliyet for January 4, 2002. Many thanks to Leyla Degirmen for this report.)
(Editor’s Comment: Another “now you see it, now you don’t” newspaper story, eh? It could be a hoax. Or maybe somebody tampered with Milliyet’s website. It’s unlikely that aliens buried one of their own in the rugged Rodolpi range. Could it be that the aliens were bushwhacked by military units operating in the area during World War II, and a dead alien was hastily buried there? Perhaps more of our readers in southeastern Europe can contribute additional information.)
Source: UFO ROUNDUP Volume 7 Number 4 January 22, 2002 Editor: Joseph Trainor
The small elliptical, metal object
Then there is some further information that has appeared in multiple news articles, which provided the following information.
The skull was found by am 38 year old resident of Plovdiv who requested anonymity to avoid problems. He said he had seen five people dressed in yellow metallic clothes, told him in his sleep! He said.
He found the skull in the Rhodope Mountains in Bulgaria (Rhodopi in Bulgarian), situated somewhere between Ardino and Madan, about 200 kilometers (120 miles) south of Sofia, the country’s capital. The man, who chose to remain anonymous discovered the buried skull buried with a small elliptical metal object lying next to it.
He initially presented his find to a narrow circle of people interested in the paranormal but the skull did not remain secret for long.
Scientists gathered in Asenovgrad, Plovdiv Province, southern Bulgaria, to discuss the rare find, including Professor Yordan Yordanov, one of the most famous in Europe, who said “He had never before in his life seen a human or animal skull like this. Anthropologist Melamet Katya, one of the archaeologists and member of the Bulgarian Academy of Sciences, also said “I have never again seen anything like it.”
The skull was examined by archaeologist Katya Malamet of the Bulgarian Academy of Sciences and by Professor Dimiter Kovachev, the Director of the Paleontology Museum in Asenovgrad. Dimiter Kovachev said it is not a fossil and does not resemble any hominid skull known to science. “We couldn’t find any analogy or correlation with anything from the past 30 million years.”
The skull is as small as a human baby’s but its bone structure is lighter and thinner and it weighs only 250 grams (8.8 ounces). It has six cavities that researchers think belonged to the alien’s sensory organs. When alive, this being possessed six eyes or perhaps other completely unknown organs. Interestingly, it has no mouth hole where we would expect to find one.
An initial examination was done on the skull. A DNA test showed that it does not match any known species on Earth.
X-rays showed that the skull probably contained a brain, and there were no seams anywhere in the skull, and that it was dense with blood vessels.
There are miniature holes like the pores on the skin (scientists think these wholes has something to do with protecting the bone from high pressure) and there are trails of crystallization of the bone. Micro photos have been taken from the surface and from a sliced piece of the backside of the skull.
The Bulgarian villager who found the skull said that he had been made several generous offers to sell it.
The skull, along with the metal part, was stored in the Regional Historical Museum in Plovdiv (second largest city in Bulgaria), pending further investigations. It seems that the skull was then transferred to another museum, after which it disappeared.
While the images above can be found in the Western news reports, the images below I found on multiple Chinese, Taiwanese and Japanese sites. They are probably from the Asenovgrad conference.
This is a cut into the skull, showing the structure of the bone: