155 years after its original discovery, excavation began last week on the earliest known sauropod dinosaur fossil found in North America near a portion of the Old Spanish Trail in San Juan County.
The project was spearheaded by paleontologist and Museum of Moab director John Foster, and is a collaborative effort between the museum, the University of Utah (U of U), and the Bureau of Land Management (BLM), and is funded through grant from the Canyonlands Natural History Association (CNHA).
Foster said that the project is “multi-faceted” in interest, and that it has historic, scientific, and local significance.
“Historically, this was the first documented dinosaur find in Utah,” he said. “Scientifically, this could be pretty important in helping us determine where North American sauropods came from.”
Sauropods were long-necked, long-tailed, plant-eating dinosaurs, one of the more well known of which was the Apatosaurus, or formerly named Brontosaurus. Sauropods have been found on all continents except Antarctica.
Curator of paleontology at the Natural History Museum of Utah, and U of U assistant professor of geology and geophysics Randy Irmis, said the find is significant for its location in the geologic column.
“It’s located in the Tidwell layer at the bottom of the Morrison formation, which makes it 155-160 million years old,” Irmis said. “This is the oldest skeletal material of a sauropod ever found in North America.”
The original discovery was made by Dr. John Strong Newberry, a geologist and naturalist on the 1859 San Juan Exploring Expedition led by Capt. John N. Macomb. The expedition left from Santa Fe, New Mexico, and was charged with exploring the “San Juan Region,” which included locating the confluence of the Grand (Colorado) and Green rivers.
While exploring the region, Newberry uncovered “saurian bones” and sent them to the Smithsonian Institute, where he encouraged further study by one of America’s first vertebrate paleontologists, Professor Joseph Leidy.
BLM paleontologist Rebecca Hunt-Foster said that the limb bones that were sent to the Smithsonian were a humerus, ulna, and radius, as well as hand-like bones called metapodials.
“Newberry wanted this fossil to be excavated,” she said. “Unfortunately, Leidy didn’t do much.”
Newberry’s find was eventually described in 1877 and given the name of Dystrophaeus by paleontologist Edward Drinker Cope.
The site was not revisited for another 128 years until the late Fran Barnes, of Moab, relocated it through a meticulous reading of Newberry’s journals, and by extensive on-the-ground exploration.
Barnes spent more than 30 years exploring, studying, and writing about the Canyon Country region of southeastern Utah. Retracing the steps of the Macomb Expedition became the source of great fascination for him because of its historical significance to the region.
“It took Fran 15 years to find it,” Foster said. “It’s nearly miraculous that he did.”
In spite of how important Newberry thought the discovery was, he left surprisingly scant notes as to the location. In a letter to professor Leidy, he said only that, “… the locality is directly on this Old Spanish Trail and can be readily recognized.”
Barnes, in writing about his discovery of the site wrote, “In reality, while we did find the “locality” in 1987, it did not turn out to be “readily recognized,” but was lost in the rugged hinterlands of Canyon Country for 128 years, partly because it was in an obscure location that was difficult to reach.”
In 1989, Barnes, and Dave Gillette, a paleontologist from Northern Arizona University, began to excavate the site.
Foster, who visited the site with Gillette in 1998, said that Gillette wanted to compare specimens from Barnes’ discovery with those of Newberry’s that were in the Smithsonian. The comparison came up positive, but funding and the complicated logistics remained barriers to a full excavation.
“Logistically, this is one of the most complicated sites we’ve worked,” Foster said. “Not just difficult, but dangerous.”
The excavation is being conducted on a steep narrow slope near the edge of a cliff of Entrada sandstone. Access is difficult, and specimens cut from the rock are lowered by ropes to the ground.
“We try to expose as little bone as possible in the field,” Irmis said. “We leave them encased in rock until we can get it back to a controlled environment.”
Blocks cut from the slope containing fossils are wrapped in “jackets” of burlap and plaster for safe-keeping during transportation. Marks are made on the jackets through the use of a map square to record the precise location and orientation of specimens in the quarry.
Foster said that most of the time, they can’t identify exactly what’s in the blocks other than to say that they are bones, until they get them back to the lab, but that he thinks there is good potential for finding different zones of the skeleton at this site.
Visible noteworthy specimens found so far include three sections of tail vertebrae.
“Vertebrae tell us a lot more than limb bones,” Foster said. “They will help us know how this (sauropod) is related to other sauropods.”
Hunt-Foster said that this was an important find.
“It will help us better understand how sauropods evolved,” she said. “It will give us a better understanding of the fossil record in Europe, and help us better understand how sauropods expanded out through different continents.”
Foster said that he was most excited about doing work on Thursday, Aug. 28.
“It will be fun to work out here on the 155th anniversary of the original find,” he said.
This phase of the excavation wrapped on Sunday, Aug. 31, and all of the specimens were sent to a lab at the U of U where the jackets will be taken off and the rock chipped away.
“Then we will find what we have in there,” Foster said.
Foster said that he hopes to have some of the bones come back down to the museum, hopefully on a long term loan. The museum doesn’t have “repository status” to permanently store dinosaur fossils on federal lands, but Foster hopes that will change some day. He also said that a cast of the fore limb that Newberry found is on display at the museum.
Foster would like to thank the BLM for working with them on the project. He said he was pleased with the results, and that he plans to go back and excavate more.
“We’ve been pleasantly surprised at the amount of the material we found at the site,” he said. “We’re optimistic that more can be learned.”
Project led by paleontologist and Museum of Moab director John Foster
“It’s located in the Tidwell layer at the bottom of the Morrison formation, which makes it 155-160 million years old. This is the oldest skeletal material of a sauropod ever found in North America.”
