I would say there were. Except they wouldn’t believe in a pantheon of gods....polyatheists?
Well within the context of the subject at hand, I would say they believed there was something “greater than man” from which the concept of morality originated for them.
I’ve also never met a “real” atheist face to face. I’ve met a LOT who claim to be, but once qualifying questions are asked, eventually every single one of them admitted they just weren’t sure. That is, by definition, an agnostic viewpoint.
An Atheist believes there is no god just as Christians believe that Jesus was God in the flesh. And if a person truly believes that, then all morals come from within. They are, in fact, their own god - the wellspring of all moral laws. Further, it means they believe there is no “intelligent” creator and therefore no morals whatsoever. That is, anything created “by accident” has no moral implications. To preserve or destroy it is not an act of morality any more than kicking a rock in the desert is an act of morality.