They were a unique product of rabbinism; and the authors of the system were also the compilers of its literary expression, the Talmud.
It was Christianity that preserved Jewish apocalyptic, when it was abandoned by Judaism as it sank into Rabbinism, and gave it a Christian character either by a forcible exegesis or by a systematic process of interpolation.
But after the fall of Jerusalem, partly through the need for systematizing the traditional post-biblical law, and partly through disputes with the Christians, orthodox Rabbinism received the stamp which has since characterized it.
But they had reckoned without the isolating influence of Rabbinism.
The latter prepared a great summary of all Jewish religious and civil law, the standard work upon which Christian theologians from the 16th century onwards based their studies - and also their criticisms - of early Rabbinism.