in ancient times, a Jewish scholar attached to one of several academies in Palestine (Tiberias, Sepphoris, Caesarea) or in Babylonia (Nehardea, Sura, Pumbedita). The amoraim collaborated in writing the Gemara, collected interpretations of and commentaries on the Mishna (the authoritative code of Jewish oral laws) and on its critical marginal notes, called Tosefta (Addition). The amoraim were thus the successors of earlier Jewish scholars (tannaim), who produced the Mishna and were themselves the creators of the Talmud (Talmud and Midrash) (the Mishna accompanied by the Gemara). Writing in various Aramaic dialects interspersed with Hebrew, the two groups of amoraim began work about AD 200 on the Gemara section of the Talmud. Because the Babylonian amoraim worked about a century longer than their counterparts in Palestine, completing their work about AD 500, the Talmud Bavli (“Babylonian Talmud”) was more comprehensive and, consequently, more authoritative than the Talmud Yerushalmi (“Palestinian Talmud”), which lacks the Babylonian interpretations. In Palestine an ordained amora was called a rabbi; (rabbi) in Babylonia, a rav, or mar. See also Talmud (Talmud and Midrash).