The Karanovo seal

This stamp seal was found in Karanovo tell (a settlement mound), in the Maritsa Valley, near the modern city of Nova Zagora (central Bulgaria). Karanovo is the best known of these settlement mounds. The excavation, made by Bulgarian archaeologist Georgi I. Georgiev, has revealed artefacts and house plans of three millennia. In fact tell at Karanovo has accumulated 12 meters of cultural deposits from the Neolithic to the Bronze age. This tell was formed in layers over the centuries as wattle-and-mud houses were levelled and rebuilt about once each generation.
The disk measures six centimetres in diameter, is two centimetres thick and with a handle 2 cm long. It is inscribed with the ancient European script and for this reason it was probably an object of prestige, placed in a prominent position and possibly used in religious ceremonies.
The Karanovo seal was discovered in the remains of a house destroyed by fire; an incident which slightly scorched the seal, but ultimately has contributed to its fine state of conservation.
The signs inscribed on the Karanovo seal are divided into four groups by the arms of a cross. The signs are straight, abstract and it is impossible to connect them to any forms belonging to the "real" world. This inscription is 6,800 years old.
Richard Flavin proposes that the incised characters from Karanovo bear a remarkable resemblance to the constellations which make up the western zodiac, in a somewhat sequential order.

References:

Flavin Richard D., "The Karanovo Zodiac" in Epigraphic Society Occasional Papers, Vol. 20, 1991
Flavin Richard D. "The Karanovo Zodiac and the Old European Linear", in Epigraphic Society Occasional Papers, Vol. 23, 1998
Gimbutas, M., The Goddesses and Gods of Old Europe, 2nd ed., U. of C. Press, 1982
Merlini M., Was Writing Born in Europe? Searching for a Sacred Script, Rome ( in preparation )
Mikov, V., Georgiev, G. I., and Georgiev, V. I., "L' inscription du sceau circulaire de Karanovo - la plus ancienne ecriture d' Europe," Arheologia 11, Sofia, 1969, 4-13 (in Bulgarian).