First: You can do an advanced filter in your excel workbook to copy a unique selection on another range of the same sheet. Steps to do this are: 1. Go to your "DATA" Tab - search for a button called "Advanced". 2. There you see a dialogue as screenshot attached here. 3. Click OK. 4. Enjoy your unique filter :)
Second: Only you can decide which rows are the actual ones. There is no Excel tool whitch does know without versioning, which one of your duplicate rows is the latest saved one. Unless you have saved it within OneDrive or SharePoint, which do the versioning automatically.
Do not want to thread jack but I think the OP is having the same issue I'm having. I have attached an example of what I am trying to do and our problems might match up. The right column (B) has my duplicate numbers which correlate to batches of serial numbers in column (A) that I need to keep. Max three pieces per batch. Any idea on how to use the sort function or other to not lose the serial numbers?