Nodosaurids like Mymoorapelta had narrow snouts, an adaptation seen today in animals that are selective browsers as opposed to the wide muzzles of grazers. In ankylosaurs, the Jurassic and mid-Cretaceous forms with narrow and pointed muzzles were apparently the most selective feeders, akin to extant mammalian browsers. This is in stark contrast to the later ankylosaurs that were adapted to bulk feeding on food with lower nutritional value.
This is evident in nodosaurids such as Mymoorapelta, which possessed narrow snouts, a characteristic observed in contemporary animals that are picky eaters compared to those with wide muzzles found in grazers. In contrast, the early ankylosaurs had narrower and pointed snouts, which were likely the most discerning feeders, similar to modern mammalian browsers.