The Swedish physician and botanist Carolus Linnaeus ( 1707-78) made the breast the formost identifying feature of the class of animals previously called “Quadrupeds”, when he renamed them as “MAMMALIA” in 1752. (from the Latin mammae, milk-secreting organs)
If it hadn’t been for the eighteenth-century European (male) fixation on female breasts ( wet nursing / breast feeding ) we might not have been called “Mammals” today…