That's a self-extracting crank. It's supposed to pull the crank as you remove the crank fixing bolt but I suspect your crank is pretty tightly seized in place so it doesn't want to come.
If it was my bike I'd use a pin wrench to remove that little ring surrounding the crank fixing bolt. Then the crank fixing bolt will probably come out fairly easily. Lastly, I'd use a crank puller (the one with the black handle) to pull the crank off of the sip-ndle.
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