And to Seth, to him also there was born a son; and he called his name Enosh (iv, 26). Abba Cohen Bardela was asked: "[Why does Scripture enumerate] Adam, Seth, Enosh, and then become silent?" "Hitherto they were created in the likeness and image [of God]," he replied, "but from then onward Centaurs were created."
(Gen. Rabbah 23.6; trans. Freedman)
Lest anyone get too excited to find centaurs in midrash, in his notes Freedman assures the reader that literal centaurs are not meant, but metaphorical, or spiritual ones; that thenceforth, humans undergo a depreciation of divine spirit, and, by implication, an increase in animality. Spiritual centaurs; incompletely human, having lost the image and likeness of God and instead the image and likeness of beasts. This means, therefore, that all humanity after Enosh are "centaurs"--that's you and that's me!