Some researchers are proposing to classify the monstrous Tyrannosaurus rex as three species — not just one — in an assertion that is drawing some controversy in the paleontology world.

The T. rex roamed North America 76 million years ago in the Cretaceous period, inspiring modern-day awe, fear and trepidation that something so fierce and so big ever occupied the Earth.

For the record, the T. rex could be as long as 40 feet, as tall as 12 feet and weigh as much as 15,500 pounds.

When a family of T. rex decided to go to dinner, it must have been a terrifying thing for any creature around it.

Was T. rex a lone wolf or social eater? New research at dig site offers surprising answer

Paleontology has always held the belief that the T. rex was a singular, ominous species but research published in Evolutionary Biology on Tuesday points to the possibility there may have been three species.

“New analysis, based on a dataset of over three dozen specimens, finds that Tyrannosaurus specimens exhibit such a remarkable degree of proportional variations, distributed at different stratigraphic levels, that the pattern favors multiple species at least partly separated by time; ontogenetic (the development of an organism) and sexual causes being less consistent with the data,” according to the abstract.

Simply put, enough variations in the fossil record examined by a trio of researchers suggests to them there were a couple more species of the T.rex.

According to a news report published by Reuters, the scientists believe the two additional species are T. imperator, or tyrant lizard emperor, and T. regina, tyrant lizard queen.

The Reuters article went on to point out disagreement over the conclusion, with one researcher in Scotland who said there needs to be stronger evidence.

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Why this 300 million-year-old fossil discovered in Utah has the paleontology world buzzing

The research was done by independent paleontologist Gregory S. Paul, and W. Scott Persons IV and Jan Van Raalte, both with the College of Charleston in South Carolina. According to his online biography, Paul has named several dinosaurs, had several dinosaurs named after him and worked on the movie “Jurassic Park” as a dinosaur specialist advising on skeletal and muscle plans.

Utah is a treasure chest for paleontologists with new discoveries popping up all the time.

In fact, this scientific discipline is taking off worldwide and public interest along with it.

Brrr! Antarctic dinosaurs debut in Salt Lake City at Natural History Museum

Last year, the Utah Legislature established the 8,000 acre Utahraptor State Park, where over 5,500 bones representing more than 10 dinosaur species have been recovered during the site’s 45-year history of excavation and discovery. 

Paleontologists have discovered about 45 new dinosaurs every year since 2003

Scientists believe 100,000 or more other fossils await discovery at the state park.