1 shapefile....duplicate features

I created a shapefile by merging to other ones together but now some of the polygons have more than one feature....I'm guessing the merge somehow caused this:

Attachment 27552

Does anyone know how to delete the duplicate feature from the shapefile? It holds the exact same info so I don't really need it....plus it's messing up my computations using Zonal Statistics tool :mad:

Any suggestions??

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