In 1994 Merritt Ruhlen claimed Eurasiatic is supported by the existence of a grammatical pattern "whereby plurals of nouns are formed by suffixing -"t" to the noun root ... whereas "duals" of nouns are formed by suffixing -"k"." Rasmus Rask noted this grammatical pattern in the groups now called Uralic and Eskimo–Aleut as early as 1818, but it can also be found in Tungusic, Nivkh (also called Gilyak) and Chukchi–Kamchatkan—all of which Greenberg placed in Eurasiatic. According to Ruhlen, this pattern is not found in language families or languages outside Eurasiatic.