I understand, and they're definitely a direct link to death metal if nothing else, but I still say Death is probably the true originator of death metal.

Seven Churches and Scream Bloody Gore are not that different in style imo, it's just that the former is older and actually has a song on it called "Death Metal".

This may not be considered a death metal album, but Reign in Blood was, imo, one of the earliest and biggest influences on the genre.