Some beetles from the Tenebrionidae family are sometimes confused with some beetles from the Chrysomelidae family (Leaf Beetles) such as the Bloody-nosed Beetle (Timarcha tenebricosa).
However, a clear difference is that the feet of the Bloody-nosed Beetle are clearly different and the end of the shins do not have a thorn.
In my photos, the thorn on the shin of this Tenebrionidae sp. is clearly visible.

Rostushe, Mavrovo National Park, Macedonia, 1 May 2023