Discovery During a prospecting survey carried out in the Permian red sandstones outcropping in badlands on the western flank of the Cayla Hill (commune of Valady, northwest of Rodez), the paleontologists Denise Sigogneau-Russell and Donald Eugene Russell discovered in the summer of 1970 the skeletons of two herbivorous reptiles. An eroded vertebra picked up on the western slope of the hill led the scientists to explore the surrounding canyons where they discovered a large articulated skeleton still in place in the sediments but damaged by erosion. The skull, neck, most of the limbs, and the tail had been washed away and destroyed. On the southeastern flank of the same hill, the same team discovered a bone fragment from a different animal. The systematic exploration of surrounding slopes permits the discovery of bones still in place in the rock belonging to a smaller animal than the first. The whole back of the skeleton had already destroyed by erosion. The right forearm was exposed at the surface of the rock, then was found the skull, several articulated cervical vertebrae, the left forearm articulated with the complete left manus, a piece of the right humerus and parts of the right shoulder. Both specimens were identified as caseids pelycosaurs. The smaller specimen found at about two kilometers horizontally from the first skeleton, but 120 meters lower stratigraphically, was described in 1974 and assigned to a new species of the genus Casea, Casea rutena. This animal was celebrated as the first caseid found in Western Europe, making of this species a geographical link with other specimens of the family that were previously known only in the south central United States (Texas and Oklahoma) and in the northern European Russia. In 2008, a phylogenetic analysis of Caseidae demonstrates the paraphyly of the genus Casea, the French species representing a distinct unnamed genus. Three years later, the species Casea rutena was removed of the genus Casea and assigned to a new genus, Euromycter, in the new combination Euromycter rutenus. In the same article the authors described the larger and stratigraphycally younger skeleton from the Cayla Hill, and assigned it to a new genus named Ruthenosaurus. Classification In the first phylogenetic analysis of the caseids published in 2008, Euromycter, then still designated as “Casea” rutena, was recovered as the sister taxon to a derive clade containing Ennatosaurus tecton, Cotylorhynchus romeri and Angelosaurus dolani. Below the first phylogenetic analysis