Use this tool, located on Tools Menu > Show Map Editing Tools > Advanced Tools > Feature Management Tools, to consolidate any duplicate features and all their child entities into one feature.

To combine duplicate features

1) Specify a layer in the Current Layer pull down list.

2) Select this menu item from the  menu.

3) Answer yes to continue.

Notes:

•Feature are considered to be duplicate if their key field values match.

•See also Delete Duplicates and Report Duplicates tools.