Musnad Ahmad 1221:4

Sufyan narrated to us, from ‘Amr, from ‘Ata’, from Habibah bint Maysarah, from Umm Kurz al-Ka‘biyyah, from the Prophet, peace and blessings of Allah be upon him, that he said: "For the boy, two equivalent sheep, and for the girl, one sheep." Abu ‘Abd al-Rahman said: I heard my father say: Sufyan makes mistakes in these hadiths; ‘Ubayd Allah heard them from Siba‘ ibn Thabit.