Large capped.......when full extended it was almost the size of a dinner plate. The cluster were located in dark, damp mound that was built like the old Indian mounds.....with lots of wood stablizers. I don't know the kind of wood but all kinds of Coprinus/Coprinoid species have popped up here in the past couple years. These are new for me....Normally I see Shaggy Mane, Mica Cap, Inky Cap, Orange Mat.......the usuals..........these? Have me stumped. Extremely heavy...very plump and firm to touch.... I also found them growing in a cluster of trees.....I think were Oak from the other fungi growing on and around. Any ideas?