I took this picture of a fruit when visiting an arboretum in zone 6b. I remember the guide talking about an invasive species, but I can't remember if it was related to the fruit or if it was about some other tree. I have used Google images to find the name of the tree, but it didn't work. I have the option of waiting until next november to make another visit and to ask the guide, but I hope it won't be the case. The location of this is Parcul Dendrologic, Simeria Romania.
If those leaves came from the same tree that produced this fruit then my money's on Cornus kousa. The seed case or fruit shown in your photo is well past its best, but still just about recognisable and pretty much umistakeable. This image here shows a particular variety of C. kousa, but fruits are similar on all varieties http://www.mesarbustes.fr/cornus-kousa-cristina-cornouiller-a-fruits-comestibles-greffe.html