Described in 2021 by Fontenelle, Simone, and Cavallari, it is endemic to the Atlantic Forest in southeastern Brazil, specifically in the Vale do Ribeira region, encompassing the states of São Paulo and Paraná.

The protoconch is notably darker, featuring a distinct lighter subsutural band, with microsculpture composed of granules and macrosculpture of well-defined axial riblets that branch apically near the suture.

[1] Internally, Megalobulimus dryades possesses distinctive jaw and radular features, and a long, convoluted penis bearing two flagella.

[1] A species endemic to Brazil, Megalobulimus dryades primarily inhabits the middle and lower Rio Ribeira do Iguape Basin in southern São Paulo and northeastern Paraná in the Atlantic Forest Biome.

[1] While specific conservation assessments for M. dryades are not detailed in the available literature, its endemism to the Atlantic Forest, a biome facing significant environmental pressures, highlights the importance of habitat preservation.