You may have male vines; many wild types come in two separate sexes. Do the flowers open? They are pretty tiny, but look for the flowers structures indicating male or female.

I don't know, but I will be interested when you find out. The fruit looks like some kind of magnolia fruit. But the tree is wrong. The tree looks and sounds like it just might have been a pawpaw, but the fruit is wrong. I hope someone knows.... I will be interested.

With thorns that size and shape, I'd say you have a rose bush, especially with the smooth texture of the stem surface. Blackberries have similar size and shape but not the color separation from the stem color IME and usually some ribs instead of a smoothly round stem. Raspberries have much finer, almost hair-like thorns. Cynthia Schuster, if you post a photo of your unknown vine here or of any unknown plants on the Name that Plant forum, you will probably get them accurately IDed.

I was reading on the internet that in Ecuador, they make jelly, pies and other things out of these berries when they're ripe. It's said that the unripe berries are very toxic and deadly. Here's another photo of what I've got growing -- a wider view, partly shaded. These haven't been intentionally watered and we haven't had a whole lot of rain in recent weeks. I did water them today to help them out, but I'd just as soon get rid of them if I can't eat them. lol I showed this to my elderly neighbor-friend across the street and she immediately identified them as Lantana as well as telling me the story of when she was in ag class making all the boys look bad in school because she already knew so much about plants. :) Thank you all for the responses!