The present article illustrates that the specific articulatory requirements for voiced alveolar or dental stops can cause tongue tip retraction and tongue mid lowering and thus retroflexion of voiced front coronals. This retroflexion is shown to have occurred diachronically in the three typologically unrelated languages Dhao (Malayo-Polynesian), Thulung (Sino-Tibetan), and Afar (East Cushitic). In addition to the diachronic cases, we provide synchronic data for retroflexion from an articulatory study with four speakers of German, a language usually described as having alveolar stops. With these combined data we supply evidence that voiced retroflex stops (as the only retroflex segments in a language) could have emerged from dental or alveolar voiced stops because the voiced front coronal plosive /d/ is generally articulated in a way that favors retroflexion, that is, with a smaller and more retracted place of articulation and a lower tongue and jaw position than /t/. The present proposal thereby supplements the observation made by Haudricourt (1950), Greenberg (1970), Bhat (1973), and Ohala (1983) that retroflex voiced stops can emerge from voiced coronal implosives for articulatory and aerodynamic reasons.