A baby snapping turtle will usually have raised ridges on the carapace ( top of the shell). It will also have an long tail. Also there are two common species the common snapping turtle, and the alligator snapping turtle.
this is a photo of a baby alligator snapper: The common snapping turtle looks similar but is not a rigid. If this is not the photo of the turtle that you have. Then you can submit a photo using the tree icon. Also if you need care information let me know.