Khalid bin Ma'dan narrates: Abu Ubaydah bin al-Jarrah (may Allah be pleased with him) offered the funeral prayer over (severed) heads.
Imam al-Shafi'i (may Allah have mercy on him) says: It has reached us that during the Battle of the Camel a bird dropped a hand in Makkah, and the people recognised it by its ring, so they washed it and offered the funeral prayer over it.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الجنائز / 6826