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
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: