(CN) After a nearly seven-year dispute over the ownership and definition of dinosaur fossils — including the remains of a rare Tyrannosaurus rex — the Montana Supreme Court has found they are not considered minerals.

This week’s ruling stems from a series of miraculous discoveries by Mary Ann and Lige Murray. Beginning in 2006, the Murrays began uncovering rare and extremely valuable dinosaur fossils on their Montana property, discoveries that included the fossilized remains of two dinosaurs locked in combat, the foot and skull of a Triceratops and, arguably their biggest find, an almost complete Tyrannosaurus rex.

According to court documents, these fossils possess tremendous scientific value given their rarity. The remains of the two dinosaurs locked in perpetual struggle, known as the “Dueling Dinosaurs,” alone is likely worth several million dollars.

In the years following these discoveries, the Murrays began to sell some of the prehistoric relics. The Murrays sold the Triceratops foot for $20,000, have offered to sell the sell the Triceratops skull for $200,000 to $250,000 and sold the T. Rex skeleton to a Dutch museum for several million dollars.

These profits have been held in escrow, however, as the fossils have also been the source of a long legal dispute.

In 2013, BEJ Minerals and RTWF LLC claimed an interest in the fossils as mineral titleholders to the property in question. While the Murrays owned the land where the dinosaur fossils were found, they shared mineral rights, such as oil, gas and coal, with other companies.

BEJ Minerals and RTWF claimed the fossils should be considered minerals and therefore part of the mineral estate they have an interest in.

The Murrays later sought judgment proclaiming them the sole owners of the dinosaur fossils and that the fossils are not minerals. In 2016, U.S. District Judge Susan Watters, an Obama appointee, granted summary judgment and declared the Murrays the owners of the fossils.

An appeals battle soon followed that put the matter into the hands of the Montana Supreme Court by way of a certified question from an en banc Ninth Circuit.

During a hearing at the Montana Supreme Court this past November, the Murrays’ attorney Harlan Krogh argued that ordinary understanding of what dinosaur fossils are and how they came to be clearly shows that they are not minerals. He told the justices that dinosaur bones are not rocks or similar enough to oil to be held under the same definition standard of a mineral, citing the different sets of geological processes.

“If I’m playing 20 questions with my grandchildren, and I say it’s a mineral and it ends up being a dinosaur fossil, I think they’re going to be mad,” Krogh argued.

Eric Wolff, representing BEJ Minerals, told the justices it is clear and legally understood that the fossils should be treated as minerals.

“I believe all the arrows point to these very valuable fossils being minerals,” Wolff said. “These are rocks, and very valuable rocks in Montana are minerals. It’s as simple as that.”

Writing for the high court, Justice Laurie McKinnon found a dinosaur fossil simply does not constitute a mineral.

McKinnon wrote that a mineral is traditionally used in a refinement context, something that is taken from the ground as a raw material and then used for some economic benefit. Oil, gas and other hard compounds fall under this definition quite clearly.

But a dinosaur fossil is a different story, McKinnon found, as its value and purpose are derived in entirely different ways.

“Although a material’s mineral content may render the material rare and valuable, and therefore within the ordinary and natural meaning of ‘mineral,’ dinosaur fossils are not considered rare and valuable because of their mineral properties; rather, fossils are valuable because of characteristics other than mineral composition,” McKinnon wrote for the court.

She pointed out that, unlike minerals, not all dinosaur fossils are rare. While a mineral retains its rarity through its composition, a dinosaur fossil’s value varies wildly due to a number of archaeological factors. These can include what kind of dinosaur the fossil came from, the completeness of the skeletal remains and the overall quality of the bones themselves.

McKinnon also noted that while minerals are found and used through economic procedures, dinosaur fossils are found largely by sheer luck.

She also found that a dinosaur fossil is most closely related to the surface of a property. Dinosaur bones are excavated and not mined like minerals, and the excavation process is directly linked and influenced by the surface of a property.

Because the Murrays own the entire surface estate of the Montana property, the Treasury State’s high court said the fossils belong solely to them.

The case goes back to the Ninth Circuit for resolution based on the Montana high court’s answer.

The parties’ attorneys did not respond to requests for comment by press time.

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