Jura-tri*as"sic

from The Collaborative International Dictionary of English v.0.48

Jura-trias \Ju`ra-tri"as\, n. (Geol.)
   A term applied to many American Mesozoic strata, in which the
   characteristics of the Jurassic and Triassic periods appear
   to be blended. -- {Ju`ra-tri*as"sic}, a.
   [1913 Webster]