The page does not call the animal a bull. It is an aurochs, wild cattle that cows come from.
Debated. A scan shows the skull was set on a pine post, but a rite is only a guess.
The find is in the Duvensee Moor, in Schleswig-Holstein, Germany, at a spot called Lüchow LA 11. It is about 10,500 years old. The skull lay a few metres from a cremation grave the page calls the oldest known in northern Germany. The skull was not cut up for meat. A pine post had been pushed in through the opening at the back of the skull, then broke, leaving wood inside. Another post nearby was made of poplar.
One idea on the page is that several animal skulls once stood around the grave, and that is only a guess.
https://www.ancient-origins.net/news-history-archaeology/mesolithic-ritual-burial-00102595