"Zalmoxes" is a rather small genus of bipedal herbivore with a large triangular head and a beak. "Z. shqiperorum" is the larger species, known from a subadult long, as well as an early juvenile in length, while "Z. robustus" subadults range from long. An unnamed species of "Zalmoxes", is known from larger sizes, with an adult in length. Although Nopcsa thought the small size of "Zalmoxes" was due to island dwarfism, Attila Ösi and colleagues found it was closer to the size of the rhabdodontid ancestor, with larger "Rhabdodon" and smaller "Mochlodon" having island gigantism and island dwarfism respectively. However, when the species of "Zalmoxes" are taken into account separately, it can be seen than "Z. shqiperorum" continued the general size trend from "Orodromeus" to "Tenontosaurus", while "Z. robustus" may have had slight nanism.