I looked at San Diego Seed's website which had something that reminded me of turnips that was called Ethiopian Kale.
There was also a youtube about a Portuguese Kale.
Could what you got be either of those?
I ask Mr. Google who gave me this:
gardenknowhow said, "Turnip leaves are sometimes covered with prickly thorns. From seed collection to labeling seedlings, mix-ups can and do occur. So, if you're finding spines on kale leaves in your garden, it's possible you might have inadvertently purchased turnip plants.
It will be interesting to find out what you got.