Ennatosaurus
Ennatosaurus (meaning "the 9th reptile") was a synapsid that lived in European Russia during the Wordian stage of the Permian period. It is included in the synapsid clade Caseidae in the order Pelycosauria. "Ennatosaurus" was a herbivore, and may have been aquatic, using its broad forefeet for paddling. Like all caseids, "Ennatosaurus" had a small head compared to its wide, lizard-like body. Its mouth was lined with blunt, peg-like teeth. It lived alongside other Permian creatures, such as the herbivorous "Nyctiphruretus" and the carnivorous "Biarmosuchus". The adult size for "Ennatosaurus" is unknown. Fossil remains show an animal  about the size of a cat, but these are likely juvenile specimens, the adults growing to sizes that may have rivaled those of -long cousin, "Cotylorhynchus". "Ennatosaurus" is known from only one fossil site, where several juveniles were buried simultaneously in sand. One adult skull was found among the juvenile skeletons. References. https://web.archive.org/web/20080820051037/http://scienceblogs.com/tetrapodzoology/2007/07/the_answers_we_seek_on_goodbye.php https://web.archive.org/web/20080224042643/http://www.palaeos.com/Paleozoic/Permian/Wordian.htm Lucas, Spencer G. (1998) Permian Tetrapod Biochronology, "Permophiles: Newsletter of the Subcommission on Permian Stratigraphy" 32: 17–33