If Automatic Duplicate Management is enabled, constituent records will be automatically merged based on matching criteria.

To see which records have been merged:
  1. Select Data Management > Duplicate Management
  2. Select the Duplicate Merge Undo Management tab
You can select a specific dated tab to see which records were merged on a particular day. To see an overview of merged records, select the View All Merges tab. You can also elect to Undo a Merge.