First proven case of superfetation

In mammals, superfetation is the conception of twins from two different menstrual cycles. The existence of superfetation in humans has been supported by observations of different birth weight and bone age in twins, and even twins of different skin colour indicating two different fathers. In a 1980 German case of disputed paternity of twins, the putative father could be excluded as the father of Twin One by HLA, GLO, and Ss typing results, but could not be excluded as the father of Twin Two, with a probability of paternity for this twin of 99.995%.