A "large" discovery has been made in Utah's Cedar Mountain formation.
Scientists from Chicago's Field Museum have uncovered the remains of a "top predator" dinosaur.
Parts of the animal..... now named Siats meekerorum... were found in an ancient rock formation near the end of what had started out as an uneventful excavation.
But after extensive digging and testing scientists realized they were onto something special.
They believe the Siats tipped the scales at four-tons and was about 30-feet-tall.
Siats is the third-biggest meat eater ever found on U.S. soil and appears to be the precursor to the T-rex.
The scientists also believe there are other dinosaur remains in that same area.