There are 3-6 Glyptoguy species: a well understood G. sue, about the size of a sheep, an also fairly well understood G. giganteus, the largest of the taxa about as large as a cow, and poorly understood menagerie in between, which have been considered anything from different sexes to different morphs of a single species, as well as fragmentary remains not yet identified as recognised species. It is by far the most common herbivore of the Santa Lucia Formation and likely took most large sized browser and grazer niches, its robust and short jaws apt to deal with a variety of plant matter from grass to conifers, though likely tending towards tougher food items in general. Glyptoguy is closely related to Patagonia taxa (some contemporary Argentinian fossils have been attributed to the genus as well) and likely represents a then recent migration event from there, showcasing that northern South America underwent migrations not only from the north but the south as well.
