Wikipedia
Kogaionon is a mammal genus from the Upper Cretaceous of Romania. It lived in Transylvania the same time as some of the last dinosaurs and was a member of the extinct order of Multituberculata. It was named after the holy mountain of the ancient Dacians. It lies within the suborder Cimolodonta and the family Kogaionidae. The genus Kogaionon was named by Rădulescu R. and Samson P. in 1996.
This genus is known from one species, Kogaionon ungureanui, the fossil remains of which have been found in the Maastrichtian (Upper Cretaceous) Sinpetru Beds of the Hateg Formation in Romania. It is a micro-mammal, based on a well-preserved and near complete skull. The species name is in appreciation of the geologist, Costin Ungureanu, who found the fossil.
Kogaionon was the holy mountain of the Geto-Dacians, the place where Zalmoxis stayed in an underground cave for three years. After his disappearance into Kogaionon, he was considered dead by the Getae but after three years he resurrected and showed himself to the people, who became convinced by his holy preaching when he emerged from Kogaionon.
Strabo claims that a river with the same name flowed in the vicinity.
One modern translation of Kogaionon is "sacred mountain", which would be connected to a probable Dacian word kaga meaning "sacred", attested in two early 2nd century inscriptions from Tomis.
Kogaionon's location is still under debate, but thought to be either in the area around the Dacian capital Sarmizegetusa Regia (there is a 2291m summit there called Gugu and there are speculations that it could be the holy mountain; it may also have been Dealul Grădiştei where the ruins of the sanctuaries of Sarmizegetusa are located) or even the Ceahlău mountain, because every year on 6/7 August the shadow of the mountain forms a pyramid which is thought to have been made by the Dacians.