Museum of the Rockies excavates hadrosaur fossil from Makoshika trail

MILES CITY – The good news is that a very popular dinosaur fossil that was a fixture alongside one of Makoshika State Park's hiking trails has not been stolen, vandalized or damaged; rather, it has been excavated by Museum of the Rockies.

It's a bit of a shock to visitors who have become accustomed to seeing the hadrosaur, or duck-billed dinosaur, vertebrae along the Diane Gabriel Trail. But its connection to the park will live on.

The plan is for Museum of the Rockies to transport the fossil back to its facilities and do preservation work to get it ready for display. Once the fossil is prepared, it will be returned to the park to be put on display in the visitor's center for the public to view. The museum also has offered to help the park create interpretive signage to be placed near where the fossil was taken from along the trail.

MOR has conducted field work at Makoshika every summer since 2016, according to John Scannella, the John R. Horner Curator of Paleontology there. Removal of the hadrosaur fossil was part of this season's work.

"I was contacted by the park with the concern that, because it was positioned over a sinkhole - kind of precariously - if erosion continues it might be lost down into the sinkhole," Scannella explained.

The fossil consists of several vertebrae in a line in a sandstone concretion, part of the articulated backbone of a duckbill. Scannella estimates it to be just under three feet wide and about 300 pounds.

Scannella and his crew of mostly students wrapped the fossil in a field jacket of burlap and plaster and prepared it for the trip to MOR. Along the way they unearthed a surprise.

"Part of the hipbone was behind it, which had never been seen before because it was in the rock," he said.

The fossil represents the late Cretaceous period, which was the end of the age of the dinosaurs.

"Makoshika is one of the places where you can walk through the Hell Creek Formation, the time of the T. Rex, triceratops, probably Edmontosaurus," Scannella said.

More than 10 different dinosaur species have been discovered in Makoshika. Significant discoveries include a complete triceratops skull, the fossil remains of edmontosaurus and T. Rex, and a nearly complete skeleton of the rare thescelosaur. In recent years the dome-like skull of a pachycephalosaurus was partially exposed. The park is also one of few places in the world where you can see a sedimentary layer called the K-Pg boundary, which marks the mass extinction of the dinosaurs.

Scannella views each discovery as being important to research.

"Every fossil is potentially incredibly informative for learning more about these animals or their world," he said.

"You never know what you might find," Scannella said. "There are still many, many more discoveries to be made in the hills of Makoshika."