 The naming of these first specimens was disputed , however . Leopold <unk> named the animal <unk> in 1837 . In 1841 , English <unk> Richard Owen referred to the genus as <unk> to describe its highly folded or <unk> teeth . Owen thought the name <unk> " ought not to be retained , because it recalls <unk> the idea of the mammalian genus <unk> , or else a <unk> form of the tooth ... and because the second element of the word , <unk> , indicates a false affinity , the remains belonging , not to the <unk> , but to the <unk> order of <unk> . " Owen recognized the animal was not a " <unk> " reptile , yet he also referred <unk> 's <unk> to the genus . Although the two genera both have similarly sized conical teeth , <unk> was later found to be a crocodile @-@ like reptile . Additional material , including skulls , firmly placed <unk> as an amphibian . <unk> also named <unk> <unk> in 1828 , basing it on partial <unk> , or back portion of the skull . In 1833 , he described a complete skull of S. <unk> that had the same teeth as his <unk> , making it the first known complete skull of a <unk> . Because <unk> was named first , it has precedence over the other names as a senior <unk> synonym . <unk> is still used as the name of an unrelated <unk> <unk> . 
