Context : Understanding the evolutionary history of the Magellanic Clouds requires an in-depth exploration and characterization of the stellar content in their outer regions , which ultimately are key to tracing the epochs and nature of past interactions .

Aims : We present new deep images of a shell-like over-density of stars in the outskirts of the Small Magellanic Cloud ( SMC ) .
The shell , also detected in photographic plates dating back to the fifties , is located at \sim 1.9 \degr from the center of the SMC in the north-east direction .

Methods : The structure and stellar content of this feature were studied with multi-band , optical data from the Survey of the MAgellanic Stellar History ( SMASH ) carried out with the Dark Energy Camera on the Blanco Telescope at Cerro Tololo Inter-American Observatory .
We also investigate the kinematic of the stars in the shell using the Gaia Data Release 2 .

Results : The shell is composed of a young population with an age \sim 150 Myr , with no contribution from an old population .
Thus , it is hard to explain its origin as the remnant of a tidally disrupted stellar system .
The spatial distribution of the young main-sequence stars shows a rich sub-structure , with a spiral arm-like feature emanating from the main shell and a separated small arc of young stars close to the globular cluster NGC 362 .
We find that the absolute g -band magnitude of the shell is M _ { g,shell } = -10.78 \pm 0.02 , with a surface brightness of \mu _ { g,shell } = 25.81 \pm 0.01 mag arcsec ^ { -2 }

Conclusions : We have not found any evidence that this feature is of tidal origin or a bright part of a spiral arm-like structure .
Instead , we suggest that the shell formed in a recent star formation event , likely triggered by an interaction with the Large Magellanic Cloud and/or the Milky Way , \sim 150 Myr ago .