Although Melikov believed the skulls belonged to ancient alien visitors to Earth, some researchers believe the skulls could be demonic.
Regardless, Melikov said the skulls were "unlike anything known to man."
"Among the most mysterious features of the skulls is the absence of cranial vault and jaws," he said. "The eye sockets were unusually large having facial features resembling humans."
"Even when compared with the skull of a bear, it is hard to think that you do not have in your hands the remains of an alien creature," he added.
However, skeptics have dismissed the claims, saying they are part of an elaborate hoax. Hoax debunkers argued that the facial features of the skulls could have been assembled from parts of a large animal's pelvic bone.
Melikov sent photographs of the skulls to paleontologists in Moscow. But it appeared they thought it was a hoax because they showed little interest. They only acknowledged they had never seen anything like the skulls before.
But a few academics suggested they were sheep skull deformed by pressure over a long period of time.
The latest mysterious discoveries in Russia come after researchers uncovered evidence of the presence of Ahnenerbe operatives with elite German mountain troops known for their "Edelweisss" insignia, at the peak of Europe's highest mountain, Elbrus, in the Republic of Kabardino-Balkar and Karachay–Cherkessia, in the northern Russian Caucasus mountains.
Researchers discovered on Mount Elbrus another Nazi briefcase embossed with the emblems of Ahnenerbe, a ring and a set of Nazi uniforms. Remains of German huntsmen ("jager") were also found. It is believed that the soldiers were killed in an avalanche during the war.
During the war, the Nazis deployed troops equipped with sophisticated surveillance equipment to the Adygea region.
According to Ivan Bormotov, professor of economics at the Maikop State Technological University, SS Ahnenerbe secretly equipped expeditions to the mountains of Adygea in August 1944. But it is not certain whether the Nazis knew exactly what they were looking for or what they expected to gain from the expeditions.
But it believed that at a time that Hitler's Germany was actively engaged in developing new types of weapons capable of changing the course of the war, Ahnenerbe was investigating UFOs, seeking contact with aliens to obtain advanced technology.