The feature is a dust devil on Mars. Dust devils are spinning, columnar vortices of wind that move across the landscape, pick up dust, and look somewhat like miniature tornadoes.
Dust devils are a common occurrence in dry and desert landscapes on Earth as well as Mars.
When this dust devil was spied in Amazonis Planitia on April 10th, the MOC was looking straight down. Usually when the camera is looking down the dust devil will appear as a circular, fuzzy patch with a straight shadow indicating its columnar shape. Hunting for star clusters and double stars with binoculars or a telescope.