We present initial results from a wide field photometric survey of the Fornax dwarf spheroidal ( dSph ) galaxy .
The focus here is on a small overdensity of stars located approximately 17 ^ { \prime } ( 670 pc in projection ) from the centre of Fornax .
Based on imaging data in both V and I bands down to V \approx 21 , the dimensions of the feature are \sim 1.7 ^ { \prime } \times 3.2 ^ { \prime } ( 68 \times 128 pc ) with an average surface brightness of 25.8 mag/arcsec ^ { 2 } in V .
A follow-up analysis using the deep B and R band data obtained by Stetson , Hesser , & Smecker-Hane ( 41 ) indicates that the overdensity is apparently dominated by a relatively young stellar population with an age \approx 2 Gyr , though the current data do not rule out the presence of older stars .
Our preferred interpretation is that the overdensity represents shell structure in the Fornax dSph galaxy , a phenomenon previously unseen in dwarf galaxies .
The shell may be the remnant of a merger with Fornax of a smaller , gas-rich system that occured approximately 2 Gyr ago .
The comparitively recent star formation seen in some dSph and dE galaxies may then also be the result of infall of small relatively gas-rich systems .