Phylum: Ascomycota Family: Ascobolaceae
Ascobolus stercorarius (Bull.) J. Schröt.
A common disc fungus that grows on herbivore dung, especially cow. Variable in colour, usually starting off lime-green and becoming browner with age. However, they can also start a pale greenish-brown
References:
Brummelen, J. van (1967) A World Monograph of the Genera Ascobolus and Saccobolus (Ascomycetes, Pezizales)
Doveri, F. (2007) Fungi Fimicoli Italici
Richardson, M.J. & Watling, R. (1997) Keys to Fungi on Dung