Neither Newton nor Liebniz invented calculus single-handedly as is often described. There was a lot of precursor work. Newton for example credited the idea of the derivative to Fermat's prior work on drawing tangent lines (which itself was a generalization of ancient Greek ideas about tangents for conic sections). Others also discussed similar notions before Newton and Liebniz such as the mean speed theorem. After both of them, a lot of work still needed to be done to make calculus useful. The sections of calculus which Newton and Liebniz did is only about half of what is covered in a normal into calc class today.

A better example might be Shannon's development of information theory which really did have almost no precursors and did leap from his brow fully formed like Athena.