x1 is a mosasaur [member of family Mosasauridae] of subtaxon/type/genus/species/variety/breed x2.
Categorizer rafsi "dis" is meant (and experimentally proposed) to belong to the experimental gismu dinso; as such, it may not be the most elucidating; however, it is technically not essential to the interpretation of the lexeme. Technically, a extinct family of reptile order Squamata (which is extant), but dinso applies all the same (unlike reksa). See also: dinso, respa, reskuamata, ikfio, plesio, dinsauru, reksa, ketslau.