Hello, there is an intriguing spiral structure seen Mars Curiosity rover - it looks like an ammonite.
original image:http://mars.jpl.nasa.gov/msl-raw-images/msss/00551/mcam/0551MR2233051000E1_DXXX.jpg
could this be what it seems?
for more information please see also: http://www.mars-tourist-guide.co.uk/curiosity/detail.html?s=551&i=MAST_RIGHT&p=0551MR2233051000E1_DXXX