We report on the observation of the signatures of Majorana fermions in superconductor-semiconductor quantum dot-superconductor hybrid devices.The devices are made from high crystal-quality InSb nanowires and superconductor Nb contacts.The InSb nanowires are known to have excellent physical properties [1-3] and have therefore been considered as one of the most promising material systems for realizing topological superconductor systems in which Majorana fermions can be created.