 The type specimen of Kritosaurus navajovius is only represented by a partial skull and lower jaws , and associated postcranial remains . The greater portion of the muzzle and upper beak are missing . The length of the skull is estimated at 87 centimeters ( 34 in ) from the tip of the upper beak to the base of the quadrate that articulates with the lower jaw at the back of the skull . Potential diagnostic characteristics of Kritosaurus include a predentary ( lower beak ) without tooth @-@ like crenulations , a sharp downward bend to the lower jaws near the beak , and a heavy , somewhat rectangular maxilla ( upper tooth @-@ bearing bone ) . 
