Alan Detrich holds a horn of a triceratops, left, and tooth of a tyrannosaurus rex. Detrich recently found more than half of a triceratops in Montana and will clean and assemble the bones. He also wants the state of Kansas to choose an official fossil.

As Alan Detrich drove into Lawrence on Tuesday, he simply looked like a guy hauling a trailer full of rocks.

But Detrich, a fossil hunter returning from a two-month dinosaur-hunting expedition in Montana, said the “rocks” were plaster-casted triceratops bones that could be worth millions.

Detrich said the find could be a first in the paleontology world, as he says he collected more than half the bones of a full triceratops.

“No one has ever found a 50 percent triceratops. They’re rare,” he said.

The creatures, which date back more than 65 million years, are estimated to have grown to more than 25 feet in height and typically weighed more than 20,000 pounds.

Detrich also made some other significant discoveries on his trip, including finding a tyrannosaurus rex tooth and femur.

Up next is the lengthy process of cleaning the bones — something that could take more than a year. He’ll then work on a display of the bones and probably sell them to a museum, where the missing bones will be added from other triceratops.

In addition to fueling a life passion and earning money, Detrich said he hopes such discoveries help a cause he’s been working on for a decade: getting Kansas to declare a state fossil.

“Forty states have a state fossil; Kansas doesn’t. Go figure,” said Detrich, who created a fossil sculpture that’s stationed on the corner of Sixth and Massachusetts streets. “It’s a lot more interesting than a state flower or state weed.”