Don't think it looks like Euonymus phellomanus. So with your clue that just leaves Euonymus planipes?
Sorry levilyla, you just happened to chose a genus that I love. Not only for the interesting seed capsules but the lovely colour they go in the autumn/fall.
Have you come across this one,probably my favourite.(shame about the mouthfull of a name).....Euonymus cornutus var. quinquecornutus?