Archaeal population detected in fecal microbiota. No Archaea were detected in MI. The genus Methanobrevibacter, Methanosarcina and Methanocorpusculum were detected in the herbivorous reptiles that consumed terrestrial plant material. Triangles denote that only one LI at each location, respectively, was shown to harbor Methanocorpusculum. F-LI, land iguanas in Fernandina; P-LI, land iguanas in Plaza Sur; SF-LI land iguanas in Santa Fe.