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.
This thorn is clearly visible on the shin of the Tenebrionidae sp. on the photos.

Macin Mountains, Tulcea County, Romania, 22 May 2018