Crews from the Museum of Moab, the Bureau of Land Management, and the University of Utah have continued work this past September of 2016 at the Dystrophaeus Quarry in San Juan County, Utah, site of the earliest-known sauropod fossil in North America. In 1859 John Macomb was dispatched to find a military route through New Mexico to southern Utah, to discover the confluence of the Green and Colorado Rivers, and to conduct a scientific study of the area they traveled. Macomb took along Dr. John S. Newberry as expedition physician and scientist. On August 17, 1859, Newberry was exploring the area surrounding their camp when he came across fragments of fossilized bone at the base of the cliffs. Recognizing these fossils and their importance, he was able to find a route up to the top of these very steep cliffs, and was able to locate additional fragments, and trace them to the source in a bright burgundy and orange layer of softer rock found between layers of harder sandstone. Ten days later he would return with assistance to collect these remains. He made special note of the occurrence in his journal:
“Saurian bones – On the north side of the canyon just opposite our camp…The bones we obtained were mainly those of the extremities: a femur entire; the greater part of a humerus; several of the phalanges of the toes; portions of the ribs; and other large and to me, quite incomprehensible bones. All of these have been placed in the hands of the anatomist, Professor Leidy, who will make them the subject of a special report. The size of the animal, as indicated by these bones, must have been very large. The femur taken out measured 30 inches in length, by 4 in [inches] diameter, at its smallest part, the articulations being much thicker. A portion of the scapula which was taken out was 22 inches long and 16 [inches] wide at the broadest part, and this but a fragment. (Macomb, 1859; pg 91)”
The fossil remained undescribed until 1877 when Edward Drinker Cope began his study, and noted that the bones belonged to a sauropod, naming the dinosaur Dystrophaeus viaemalae. After this initial report, a second paper was written by German paleontologist Friedrich von Huene, in 1904. This was the last major work Dystrophaeus would receive for nearly eighty years. The site remained lost to time, with no good map or detailed description of the area available. It wasn’t until 1987 the site was relocated by Moab residents Fran and Terby Barnes, a search that took twelve years. In 1988 the Barnes took then Utah State Paleontologist Dr. Dave Gillette, to the site. They returned in September 1989 and collected bone fragments that were found on the surface, and were able to determine that the site was located in the lower portion of the Upper Jurassic Morrison Formation. Dystrophaeus represents the only known vertebrate fossils remains from this section of the Morrison Formation, and the only dinosaur known from fossil remains during this section of geologic time in North America.
Due to the logistical and expensive nature of the site to work, a new quarry was not established until 2014, 155 years after its discovery. The latest excavation work, which is now funded by National Geographic, plans to continue for the next several years.