I'm in Rio de Janeiro, Brazil, and what looks like a seed pod from a giant tree next to my apartment landed on my windowsill. I opened the seed pod and got 6 "seeds." However, they look really thin and very unlike most seeds. 
This is a view of the top of the seed. As you can see, its length is definitely less than 1 cm, possibly around 1/2 cm. The middle seems to have this strip that is a lighter shade of brown.
You can see from this photo how thin the seed is. The flatness of the seed is what makes me suspect it's maybe not a seed. However, I'm definitely no expert, so I have no idea.
These last images are photos of the tree I believe these "seeds" may have come from. However, there are other trees around my apartment that look like the one in the photo. Seeing as this specific tree is closest to my window, this tree could be source of these seeds.
Unfortunately, when I found the seed pod, I got the "seeds" out and then chucked the seed pod out the window, so I can't provide a photo of it. I'd really like to know if these things are really seeds, because in that case I'm interested in planting them.
