It is narrated from Saeed bin Musayyib (may Allah have mercy on him) that Umar and Uthman (may Allah be pleased with them both) gave the verdict of half the blood money (diyah) for a "multa’ah" (the membrane between the skull bone and flesh being cut) as is given for a "mudiha" (a wound that exposes the bone).
Hadith Referenceمسند الإمام الشافعي / كتاب القتل والقصاص والديات والقسامة / 1665
Hadith Takhrijاسناده ضعیف الابهام شيخ الشافعي: اخرجه البيهقي 8/ 83- وفى المعرفة السنن والآثار له (4903)۔