During World War 2, there were several Morgentaler (written without th) in Poland, mainly in Lodz. The Central Database of Shoa Victims's Names enlists many Morgentaler victims with obviously jewish first names. It is unlikely that these jewish Morgentalers are in relation to the Swiss (or German) family name Morgenthaler which is treated here on this website. The few survivors of these polish jews emmigrated to northern America.
A name development of its own among ashkenazi Jews in Germanic Europe is probable. Other typical jewish family names with German elements have developed on that background: Goldblum, Goldstein, Rosenthal or Feigenbaum.
However, it remains uncertain why Morgentaler (in opposition to Rosenthal for example) is written without th, while earier than 1902, all German words that taler could mean were written with th. Here is a theory for this (from Goldie Morgentaler, Canada): Yiddish, the language of the Ashkenazi Jews, is written with the Hebrew alphabet, which is phonectical and has no th sound. Later, when the name was written in the Latin alphabeth of the German language, only a t was written.
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