There are many possibilities, including:
1. 7+ ground beetles.
2. 3+ Carabus spp (Carabidae)
3. Silphidae (Carrion Beetles) - 2+ Necrophorus spp.
4. Buprestidae (Wood Borers) - Capnodis tenebrionis
5. Tenebrionidae (Darkling Beetles) - Blaps mortisaga
6. Lucanidae (Stag Beetles) - Lucanus cervus, Dorcus parallelopipedus
7. The Lousy Watchman - Geotrupes stercorarius
8. Long-horned beetles (Cerambycidae), including Prionus coriarius and lots of others, 10+
Sorry I can't narrow it down any further.... they're all big & black & beetles!
:)