Ictidosauria(redirected from Trithelodontidae)
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a superfamily of extinct reptiles of the subclass Pelycosauria (Theromorpha), closely resembling mammals in structure. Ictidosaurs are characterized by small dimensions (the size of a rat); a well-developed secondary palate resembling that of mammals; a short, broad facial skull; and double jaw articulation, formed by the articular and quadrate bones and dentary and squamosal bones. The cheek teeth are broad, with crowns having many cusps. Ictidosaurs are known from Upper Triassic deposits in South Africa.