Figure 1. Mounted skeleton of Diplodocus carnegii: the original fossil material mounted in the public gallery of the Carnegie Museum in Pittsburgh, Pennsylvania. This mount consists primarily of the holotype specimen CM 84, augmented by elements from CM 94 and CM 307, plus casts and sculptures based on several other specimens. Skeleton in left anterolateral view, with Homo sapiens Mathew J. Wedel for scale. Photograph by Michael P. Taylor.

Figure 2. The original Diplodocus molds created by the Carnegie Museum, shown in the Utah Field House some time between 1953 and 1955. In the background to the left is the mold for the sacrum and coalesced ilia, seen in right ventrolateral view with anterior to the top. The molds closely follow the shapes of the bones they were modelled from, but are noticeably bulkier. Scanned by Eileen Carr for the J. Willard Marriott Digital Library, image ID 1212242. Used by permission, Uintah County Library Regional History Center.

Figure 3. Field House Museum Director G. Ernest Untermann (left), and his wife, Staff Scientist Billie Untermann (right), grouting the cast dorsal vertebrae of the Field House’s concrete Diplodocus. January 24, 1957. Scanned by Aric Hansen for the J. Willard Marriott Digital Library, image ID 1086940. Used by permission, Uintah County Library Regional History Center.

Figure 4. Assembly of the outdoor concrete Diplodocus at the Utah Field House in 1957. (A) In right posterolateral view. The sacrum and fused ilia having been mounted on the main support to begin the process, the hind limbs, last four dorsal vertebrae and first caudal vertebra have now been added. (B) In left anterodorsolateral view, probably taken from the roof of the museum. The mount is almost complete, with only the forelimbs, their girdles and the dorsal ribs yet to be attached. Note that, contra Untermann (1959, p. 367–368), the skull is already in place. Both images scanned by Aric Hansen for the J. Willard Marriott Digital Library, image IDs 1090660 and 1090647. Used by permission, Uintah County Library Regional History Center.

Figure 5. The completed outdoor Diplodocus mount in a rare color photograph (undated). Scanned by Eileen Carr for the J. Willard Marriott Digital Library, image ID 415530. Used by permission, Uintah County Library Regional History Center.

Figure 6. The outdoor Diplodocus mount is repainted on June 22, 1967, in what was likely an periodic event. Field House employee Ivan Hall applies a mixture of linseed oil and brown stain while G. Ernest Untermann holds the ladder. Scanned by Eileen Carr for the J. Willard Marriott Digital Library, image ID 1091738. Used by permission, Uintah County Library Regional History Center.

Figure 7. The original Diplodocus molds being loaded onto a truck for shipment to the Rocky Mount Children’s Museum, North Carolina, on or shortly before July 14, 1960. From left to right: truck driver William Randolph Turnage, Field House employee Dee Hall, and Field House director G. Ernest Untermann. Scanned by Aric Hansen for the J. Willard Marriott Digital Library, image ID 1086142. Used by permission, Uintah County Library Regional History Center.

Figure 8. The second-generation lightweight Diplodocus cast as originally displayed at the old Field House building between 1994 and 2004. (A) Right anterolateral view, showing the head and neck projecting above the admission counter. (B) Left posterolateral view, emphasizing the curvature of the elevated tail necessary to fit the 76-foot-long skeleton into the 50-foot-long exhibit hall. Photographs taken in May 1999 by Chet Gottfried, using a Pentax LX camera with a 17 mm rectilinear fisheye lens. Used by kind permission.

Figure 9. The second-generation lightweight Diplodocus cast as currently displayed at the new Field House building since 2006. Skeleton in right lateral view, with Homo sapiens Michael P. Taylor for scale. Photograph by Mathew J. Wedel.

Figure 10. Double Diplodocus mount at the Museum of Science and Industry (MOSI), Tampa, Florida. Both individuals are identical, having been cast from the molds made by Dinolab from the concrete Diplodocus of Vernal. Photograph by Anthony Pelaez, taken between 1997 and 2017.

Figure 11. The elements of the concrete cast moving from Vernal to Price, Utah, on April 8, 2013. (A) The concrete cast packed onto wooden pallets outside the new Field House building, having been prepared for transportation to the Utah State University Eastern campus in Price, about 100 miles southwest of Vernal. Photograph by Steven D. Sroka. (B) The same bones having been unpacked into Ken Carpenter’s garage in Price, Utah. Photograph by Ken Carpenter.

Figure 12. Carrie Herbel, a preparator at the Prehistoric Museum in Price, sandblasting old paint off the concrete Diplodocus casts recently obtained from Vernal, on November 1, 2014. By comparison with Hatcher (1901, plate V), which shows anterior-view photographs of the cervical vertebrae of Diplodocus carnegii holotype CM 84, this appears to be the cast of the 15th and last cervical, based on the wide zygapophyseal facets, the broad diapophyseal wings, the well-developed “V”-shaped intraprezygpophyseal lamina, and the tall, well-separated halves of the bifid neural spine with little dorsal expansion.

Figure 13. The elements of the concrete cast as they are now, having been cleaned and stored in the basement storage area on the Utah State University Eastern campus in Price, Utah. Photograph by Jason Huntzinger (Utah State University).