Jonas ben Mordechai, Weyl is mentioned 25 times between 1690 and 1718. His designation in the Stühlingen family tree is 'F1.1.1'. His father was Mordechai (Model) ben Meir, Weyl.
Jonas seems to have been a model citizen. He paid his protection tax from 1690 to 1716, and did not attract any other undue attention. In 1717 his protection was declared void and he moved away with his brother Moses and Father Modell, but without leaving unpaid taxes behind. .