In the same exposure of the Kashong shale member (Moscow formation) that I found my first intact Tropidoleptus fossils I also found a number of specimens of Nucleospira concinna. I'd recognized my first specimen of that species in a fossil from Arkona and once I saw these I knew what they were.
This species is noted for the fine spines that line it's surface. they may have been for protection against predatory snails or to prevent parasitic epibonts from attaching. Below are a couple of close ups of the very thin, hair like spines that have been preserved with the shell.