I'm not sure if this belongs here, but I have seen several instances in my local parish register of a child having the term 'filius terrae' (or filia terrae for a girl) appended to the record and no mention of a father's name. In some instances the forename and surname were the same - an example being Cadman Cadman. In one instance a child such as this reached maturity, married and had children of his own. If you are researching that particular family, I wish you luck.
Having said that, this was only encountered in one particular period and may thus have been the affectation of the vicar of the time. At one time (pre 1837), the father's name was in the baptismal record, even if he was not married to the mother. What this thread suggests (and rightly so) is that we should not necessarily take the given father's name as being fact. The mother may have been a lady of loose morals and not known the father or for any number of reasons, some other person may have taken responsibility for the child.
