Maybe a slug moth caterpillar???

I was walking through my back field today to see what I could find and happened upon these strange little creatures. I thought maybe they were slug moth caterpillars, but I came up empty on bugguide. I found them on some sort of thorny weed, I have no idea what the weed is called though.

As always, you have but to look at the left side of your screen to see my location. It would make it easier if people would put that info in their profile when they are using the "Bug Identification" area of the forum. Then they would only have to mention location if it differs from their home local.