A medium to large cup fungus, initially pale yellow but darkening and flattening out as it ages.  The outer surface may be grainy, and typically the margin is serrated. 

Other Peziza species - this is a very difficult complex of species

microscope

We recommend that this is verified by an expert from a specimen before submission to NatureSpot.  Microscopic examination of spores is likely to be needed.  Also photograph in habitat, and note substrate.

On rotted wood, woodchips, dung etc..