Well you could probably write a scrip using a fractal to do the basic outline, but that is more a knowledge of math and script writing rather than a knowledge of inkscape. Once you get the out line down you could use stroke to path then jitter nodes to ruff it up some. Or us the

on sections of the shell. Then extrude under effects generate form paths as a sort cut to the 3 d effect. Mostly inkscpae is just slogging through stuff right now unless you are a good scripter.
Live paths will get tantalizing close but probably not close enough. Stitch sub paths needs two combined paths which makes it has to get lines all the way down the spiral.
Steps for first image below: Do a spiral, convert to path, brake it apart, then combine back together, duplicate since you will lose the spiral when you do the path stitch. Followed by with setting on the side. Same menu to a bend the path and finally extrude. To manipulate the spokes on the spiral individually breaking them apart
shift ctrl K. Extrude items need to be un-grouped to work with. For complicated paths a couple of un-groups to get to the individual paths.

You'll might want to read a few tutorial or watch
http://screencasters.heathenx.org/blog/ ... fects-lpe/A nice looking example of stitch subpaths.
http://www.inkscape.org/screenshots/gal ... ilight.png