Category Archives: sauropods

History of the Field Museum Fossil Halls – Part 1

The Field Museum of Natural History (variously known as the Field Colombian Museum and the Chicago Museum of Natural History) was founded by wealthy philanthropists in the wake of the 1893 World’s Columbian Exposition in Chicago. It has since expanded into one of the largest natural history museums in the world, a destination attraction and a hub for ongoing research. What follows is a summary of the historic paleontology exhibits at the Field Museum – when and how they expanded and changed, when major specimens were added, and who spearheaded these efforts.

As with my previous overviews of fossil exhibits at AMNH and NMNH, please note that I will not be discussing field expeditions or research by museum staff in any detail, as these topics are well-explored elsewhere (see Paul Brinkman’s extensive work, for starters). My primary interest here is in the public-facing exhibits, and the people who created them.

Phase I: The Field Columbian Museum

The World’s Columbian Exposition was held in Chicago in 1893, principally as a celebration of the 400th anniversary of Christopher Columbus’s arrival in the Americas. Lasting six months and attended by 27 million people, the Exposition was monumental in size and scope. Years before it even opened, there was talk about using the Exposition displays to seed a new museum, which would rival the great natural history museums in New York and Washington, DC. Eager to establish an enduring cultural attraction in their city, a group of wealthy Chicagoans – including Marshall Field, who donated an unprecedented $1 million – contributed the necessary funds to buy up many of the Exposition’s exhibits and found the Field Columbian Museum.

As the largest and most elegant of the 200 temporary buildings constructed for the Exposition, the Palace of Fine Arts became the Field Museum’s home. Frederick Skiff served as the first director, acting as an intermediary between the board of trustees and the new curatorial staff, who would manage the collections and assemble the exhibits. Skiff hired geologist Oliver Farrington to curate the earth science collections, a diverse mix of minerals, gems, meteorites, fossils, and fabricated displays purchased from the Henry Ward Natural Sciences Establishment. With thousands of specimens to catalog, Farrington was soon overwhelmed. He repeatedly asked Skiff to hire a paleontology specialist to support him, but the board (composed of the businessmen who founded the museum) was uninterested in paying more salaries or acquiring new specimens.

fossils

The model icthyosaur and thousands of fossils in cases were among the specimens purchased from the Ward Natural Sciences Establishment after the World’s Columbian Exposition. Image courtesy of the Field Museum Photo Archives.

When the Field Columbian Museum opened on June 2nd, 1894, most the 5,000-piece fossil collection was on public display. In addition to the cases of as-yet unlabled invertebrates, plants, and other small fossils, the exhibit included several large reconstructions of prehistoric animals. As of opening day, a life reconstruction of a mammoth stood in the west court, while skeletons of MegalocerosScistopleurum, MegatheriumHadrosaurus, and a uintathere stood in halls 35 and 36. With the exception of the Megaloceros, these were all replicas of mounts from other institutions. The Hadrosaurus in particular was woefully outdated, considered by contemporary scholars to have “long since ceased to have any value except as a historic attempt” (Beecher 1901).

After completing his catalog of the earth science collections in 1896, Farrington continued to lobby for a dedicated staff paleontologist. The board paid no attention until 1897, when the American Museum of Natural History and the Carnegie Museum of Natural History announced ambitious plans to scour the western interior for fossils. So began what Brinkman calls the second Jurassic dinosaur rush – a frenzied race among leading American museums to be the first to collect and mount a sauropod dinosaur. Not wanting to be left behind by peer institutions, the trustees approved the conditional hiring of Elmer Riggs to collect dinosaurs for the Field Museum.

Hadrosaurus cast on display at the Field Museum. Field Museum Photo Archives.

Hadrosaurus stands among other fossil casts in the Field Columbian Museum. Image courtesy of the Field Museum Photo Archives.

Riggs and his classmate Barnum Brown cut their teeth in paleontology while studying under Samuel Wendell Williston at the University of Kansas. The two young men took part in an AMNH collecting expedition in 1896. Brown, who had quit his studies to work for the museum, quickly became a favorite at AMNH. Concerned about his own future, Riggs sent an unsolicited letter to Frederick Skiff, offering his skills as a fossil collector and preparator. The letter crossed Skiff’s desk at an opportune time, and in the summer of 1898 Riggs was paid a small stipend for a trial collecting trip with Farrington. The expedition was a success, and Riggs was hired as an Assistant Curator before the end of the year.

Riggs’ first three collecting seasons with the Field Museum were enormously successful. In addition to the holotype of Brachiosaurus, at the time the largest known dinosaur, Riggs collected a very-well-preserved back end of an Apatosaurus near Fruita, Colorado. Nevertheless, AMNH won the sauropod race when they completed their composite “Brontosaurus” mount in 1905. The Carnegie Museum had a Diplodocus on display in 1907, and was busy cranking out casts for European heads of state. While Riggs’ Apatosaurus was more complete than any single specimen the other museums had recovered, it was still only half a dinosaur. Riggs and Farrington repeatedly lobbied the board for funding to find more sauropod material with which to complete the skeleton, but the trustees had moved on to other things.

Riggs' Apatosaurus mount stood unfinished from 1908-1958. Photo from the Field Museum Library.

Riggs’ Apatosaurus mount stood unfinished from 1908-1958. Image courtesy of the Field Museum Photo Archives.

Plans were afoot to move the Field Museum to a new lakefront campus. However, when legal issues halted progress on the new building, Riggs was granted permission to mount the partial Apatosaurus in hall 35. The plaster casts previously displayed in this space were discarded, and unfortunately are now lost to history. A gas furnace was installed on the museum grounds, which Riggs and his small team used to shape massive steel I-beams for use in the armature. The teetering sauropod hindquarters was unveiled in 1908, but if Riggs hoped that the museum administrators would want to complete the mount once they saw how absurd the incomplete skeleton looked, he was out of luck.

Indeed, the years that followed were among the most frustrating of Riggs’ career. He received no funding to collect fossils after 1910, and could only look on enviously at the thriving paleontology research and exhibit programs at AMNH and the Carnegie Museum. The institutions in New York and Pittsburgh were headed by paleontologists, and bankrolled by wealthy fossil enthusiasts like J.P. Morgan and Andrew Carnegie. By comparison, the Field Museum was controlled by trustees with seemingly little interest in paleontology. Already paid less than the museum’s other curators, Farrington and Riggs were left with meager resources and little to do until the 1920s.

Phase II: Halls 37 and 38

The Palace of Fine Arts was intended to last six months, and after ten years it was in dire shape. The roof leaked constantly, putting exhibits and collections in danger, and fences had to be placed around the perimeter to protect visitors from falling brick. Before his death in 1906, Marshall Field worked with architect Daniel Burnham to design a new home for the museum. It took years to settle disputes over where to place the building, but ground was eventually broken off Lake Shore Drive in 1915. Completed in 1920, the new Field Museum of Natural History was a gleaming marble fortress, decorated inside and out with intricate neoclassical reliefs and statuary.

hall 37

In the spirit of a classic cabinet of curiosity, some of the cases in Hall 37 contained over a thousand specimens apiece. Source

Exhibits and collections were transported by rail car, often without being removed from their display cases. Earth science exhibits found a new home on the west side of the upper level. Hall 37, an east-west facing gallery accessible directly off the west mezzanine, housed invertebrate and plant fossils. Hall 38, running north to south against the far west side of the building, contained vertebrate fossils. Although it was colloquially known as the “dinosaur hall”, this space never contained many dinosaurs. In the 1920s, the only dinosaurs to be found were the half-Apatosaurus, a Triceratops skull, an articulated “Morosaurus” (Camarasaurus) limb, and parts of Brachiosaurus. The bulk of the specimens on display were Cenozoic mammals, including horses, rhinos, camelids, and a mammoth and mastodon. There was also a life-sized “coal swamp” diorama behind a glass barrier, with large model insects suspended in flight.

This comparatively modest exhibit was expanded significantly between 1922 and 1927, when Elmer Riggs was once again able to collect fossils in the field. Thanks to a bequest from Marshall Field’s grandson, Riggs traveled to Alberta, Argentina, and Bolivia, securing many unique specimens along the way. These included several new species, like the marsupial cat Thylacosmilus and the predatory bird Andalgalornis. A colossal Megatherium Riggs recovered in Argentina was immediately mounted for display, and became one of the most memorable elements of Hall 38.

hall 38

A postcard of the partial Apatosaurus at the south end of Hall 38. Image courtesy of the Field Museum Photo Archives.

A postcard of the north end of Hall 38, featuring a South American giant sloth and other Cenozoic mammals.

Megatherium at the north end of Hall 38. Image courtesy of the Field Museum Photo Archives.

Hall 38 also boasted a spectacular set of murals by Charles Knight. The undisputed master of paleontological reconstructions and wildlife art, Knight had a long working relationship with Henry Osborn, president of AMNH. Osborn had commissioned Knight to create many large and small paintings for his museum’s fossil exhibits, but the two frequently argued over Knight’s remuneration. For years, Osborn and Knight discussed a series of immense wall canvases illustrating the entire history of life. Osborn could never get the money together, however, and Knight refused to produce any concept sketches for fear that they would be turned over to a less-skilled artist. In 1926, the Field Museum’s board of trustees asked for a meeting with Knight about an identical project for their new fossil hall. The initial discussion did not go well, and Knight walked out when the trustees started making “suggestions” about the content, color, and composition of the proposed artwork. Knight was very talented, but also very particular. He gladly accepted anatomical expertise from scientists but would not suffer meddling with the artistic aspects of his work. Fortunately for both parties, Knight’s daughter/manager Lucy intervened, securing her father the biggest commission of his career.

Knight completed 28 murals for the Field Museum, the largest of them measuring 25 feet long and nine feet high. Subjects ranged from the Proterozoic primordial soup to an iconic standoff between Tyrannosaurus and Triceratops. These images were not only painstakingly researched reconstructions based on the latest fossil evidence, they were (and still are) gorgeous works of art in their own right. With Knight’s murals in place, the Field Museum finally had a world-class paleontology exhibit.

hall 38 mastodon

The mastodon in Hall 38, with fossil horses visible beyond. Image courtesy of the Field Museum Photo Archives.

Gorgo in Stanley Field Hall. Photo courtesy of Field Museum Photo Archives.

Gorgosaurus” in the Stanley Field Hall. Photo courtesy of Field Museum Photo Archives.

Riggs retired in 1942, leaving paleontology at the Field Museum to the next generation, among them Eugene Richardson, Brian Patterson, and Orville Gilpin. In 1951, Richardson oversaw a thorough modernization of Hall 37. The number of specimens on display was drastically reduced, making room for more accessible explanations of the fossils and ten new dioramas of Paleozoic marine life. The resulting exhibit was one of the most comprehensive displays of fossil invertebrates in the world.

Although virtually no dinosaur research was done at the Field Museum between 1910 and the late 1990s, the 1950s saw the acquisition of two significant specimens for the benefit of the visiting public. In 1956, preparator Orville Gilpin assembled a Daspletosaurus (then called Gorgosaurus) for the central Stanley Field Hall. The skeleton was a surplus specimen from Barnum Brown’s years collecting along Alberta’s Red Deer River, and trustee Louis Ware spearheaded the effort to buy it from AMNH. Since the Daspletosaurus was acquired explicitly for display, Gilpin opted to skewer and otherwise permanently damage many of bones for the sake of an unobstructed, free-standing mount. In the mid 20th century, dinosaur fossils were thought of as display pieces first, and irreplaceable specimens second.

apatosaurus revised

The newly-finished Apatosaurus serves as a backdrop for an educational video shoot. Source

Two years after installing the Daspletosaurus, Gilpin finally completed Riggs’ partial Apatosaurus in Hall 38. When Edward Holt announced that he had discovered the front half of a sauropod near Green River, Utah, the Field Museum purchased the rights to excavate and display the find. Gilpin added the new fossils to the existing mount without dismantling Riggs’ heavy-duty armature. Relabeled “Brontosaurus” and erroneously given a casted Camarasaurus skull, the refreshed sauropod debuted in April 1958 – half a century after Riggs started the project.

The next three decades saw occasional piecemeal additions to the fossil halls. For example, the University of Chicago donated its entire geology collection to the Field Museum in 1965. This included a unique assortment of Permian amphibians and synapsids from the red beds of central Texas, many of them holotypes. Field Museum preparators remounted several of these specimens and integrated them into the exhibits. Nevertheless, Hall 38 never received a complete overhaul, and by the late 1980s it was quite dated. Not only were the fossil mounts in stiff, tail-dragging poses, but the stilted label copy written by curators past did not meet modern expectations for natural history exhibits. Even the vibrant Charles Knight murals looked tired behind years of accumulated dust and dirt. In short, the Field Museum was long overdue for a total re-imaging of its paleontology displays.

Next time, we’ll take a look at the Field Museum’s fossil exhibits from the 1990s onward. Stay tuned!

References

Beecher, C.E. 1901. The reconstruction of a Cretaceous dinosaur, Claosaurus annectens Marsh. Transactions of the Connecticut Academy of Arts and Sciences. 11: 311-324.

Brinkman, P.D. 2000. Establishing Vertebrate Paleontology at Chicago’s Field Colombian Museum: 1893-1898. Archives of Natural History 27: 1: 81-114.

Brinkman, P.D. 2o10. The Second Jurassic Dinosaur Rush: Museums and Paleontology in America at the Turn of the 20th Century. Chicago, IL: The University of Chicago Press.

Chicago Natural History Museum Bulletin. (March 1956). 27: 3.

Gilpin, O.L. 1959. A Freestanding Mount of Gorgosaurus. Curator 2: 2: 162-168.

Glut, D.F. 2001. Remembering the Field Museum’s Hall 38. Jurassic Classics: A Collection of Saurian Essays and Mesozoic Musings. Jefferson, NC: McFarland.

Lelièvre, M A. 2006. Evolving Planet: Constructing the Culture of Science at Chicago’s Field Museum. Anthropologica 48: 2: 293-296.

Milner, R. 2012. Charles R. Knight: The Artist Who Saw Through Time. New York, NY: Abrams.

Tubitis, T.J. 2005. Revitalizing Life Over Time: A New Look for a Very Old Topic. In the Field 76: 2: 18.

Williams, P.M. 1968. The Burham Plan and the Field Museum. Bulletin of the Field Museum of Natural History 39: 5: 8-12.

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Filed under dinosaurs, exhibits, FMNH, fossil mounts, history of science, mammals, museums, reptiles, sauropods

The Carnegie Quarry Diaspora

About 150 million years ago, a severe drought ravaged the western interior of North America. In eastern Utah, malnourished dinosaurs gathered near a dwindling river. Unwilling or unable to leave the water source, they eventually died of thirst or disease. When rain finally returned to the region, three or four successive flash floods washed dozens of animal carcasses into a relatively small depositional area to the southeast. Today, this site is known as the Carnegie Quarry at Dinosaur National Monument, and it is one of the most incredible fossil sites in the world.

Dinosaur National Monument interns collect data on the quarry wall.

Dinosaur National Monument interns collect data on the quarry wall. Source

Today, a structure encompassing a 180-foot section of the deposit (less than half its total length) allows visitors to view nearly 1400 dinosaur bones in situ. However, the fossils on display at Dinosaur National Monument represent only a portion of the material found at the Carnegie Quarry. Between the site’s discovery in 1908 and the establishment of the quarry wall exhibit, more than 20 reasonably complete dinosaur skeletons and dozens more incomplete specimens were excavated and distributed to museums in the US and Canada. No less than eleven mounted skeletons have been created from this material, and they are all still on display today. Although they are thousands of miles from their place of discovery and exhibited in four different cities, these mounts all represent individuals that lived and died in the same environment. They may have even encountered each other in life!

The Discovery

Earl Douglass was already an established fossil hunter when the Carnegie Museum of Natural History hired him in 1902. Late in the 1909 field season, Douglass was prospecting near the confluence of the Green and Yampa Rivers when he spotted a series of sauropod vertebrae eroding out of the rocks. Once Douglass and his crew began excavating the fossils, it became apparent that they had not just one remarkably complete dinosaur, but several. Douglass called it a “beautiful sight,” and CMNH director William Holland could barely contain his glee in his reports back to the Pittsburgh museum. Under Douglass’s management, CMNH crews worked at what became known as the Carnegie Quarry for 13 years. The dinosaur fossils were jumbled and often overlaid one another, so the excavators had to work on multiple skeletons simultaneously. The especially hard sandstone also slowed their work, and the team regularly resorted to huge horse-drawn plows and even dynamite to reach the fossils. Eventually railway tracks were installed to help transport blocks of sandstone out of the quarry.

In 1915, Holland successfully petitioned Woodrow Wilson to preserve the site as a national monument. CMNH crews continued to excavate until early 1923. At that point, their primary benefactor Andrew Carnegie had died, and funding for field work was dwindling. Other museums collected from the quarry periodically in the years that followed, but Douglass’s idea to contain the remaining fossils in an on-site museum was not realized until 1958.

The Mounts

CMNH

CMNH Apatosaurus. Historic photo from McGinnis 1982; modern photo source.

Apatosaurus louisae – CM 3018

The CMNH Apatosaurus was the first dinosaur discovered at the Carnegie Quarry. After Douglass first spotted the articulated caudal vertebrae in August of 1909, his crew spent several months extracting the rest of the skeleton from the rocks. The excavation continued into early 1910, and by the time they were finished they had the most complete Apatosaurus ever found – a title the specimen holds to this day. Holland mounted the 77-foot skeleton alongside the museum’s Diplodocus in just three years, at the time a record for a sauropod mount.

Holland famously left his Apatosaurus headless for decades due to a disagreement with Henry Osborn of the American Museum of Natural History. Douglass recovered a skull that almost certainly belonged to the Apatosaurus, but Holland opted not to use it because it contradicted the sculpted head already in place on the AMNH Apatosaurus mount. After Holland’s death in 1932, museum staff quietly added a casted Camarasaurus skull as a placeholder. This was finally replaced with a proper Apatosaurus skull in 1979. More recently, the team at Phil Fraley Productions disassembled and restored the Apatosaurus, along with the rest of the classic CMNH dinosaurs. Since 2007, this specimen has been back on display in a more graceful modern pose.

Fancy fisheye photo.

AMNH Barosaurus. Source

Barosaurus lentus – AMNH 6341

When the CMNH team discovered this skeleton in 1912, they assumed it was yet another specimen of the well-known Diplodocus. It was harvested for parts, with portions sent to CMNH, the United States National Museum, and the University of Utah to supplement their displays. When the specimen turned out to be the more obscure sauropod Barosaurus, it languished in pieces for many years. Barnum Brown of AMNH was making a circuit of the fossil collections at various natural history museums when he rediscovered this specimen. Through a series of purchases and trades, the Barosaurus was reunited at AMNH in 1929.

Nevertheless, AMNH quickly abandoned plans to mount the Barosaurus – the museum already had a sauropod on display, and there wasn’t enough floor space for another one. It wouldn’t go on display until 1991, when Lowell Dingus conceived of the idea to mount the Barosaurus in a spectacular rearing pose as part of the renovation of the Theodore Roosevelt Rotunda. Peter May took on the project – one of the first mounts produced by his company Research Casting International. The resulting display, actually a cast, is the tallest free-standing dinosaur mount in the world.

ROM Barosaurus.

ROM Barosaurus. Source

Barosaurus lentus – ROM 3670

Douglass recovered a second partial Barosaurus skeleton in 1912, which consisted of a mostly complete torso and parts of each leg. It stayed in the CMNH collections for many years, until they traded it to the Royal Ontario Museum in 1962. ROM staff intended to mount the skeleton, but once again this was cancelled due to a lack of space. David Evans was developing a new ROM paleontology exhibit in 2007 when he learned that the museum had most of a Barosaurus sitting in its collections. With only weeks remaining before the exhibit’s opening, Evans tapped Research Casting International to mount the sauropod, supplemented with a replica neck and tail from the AMNH version.

Allosaurus fragilis – CM 11844

Several Allosaurus specimens are known from the Carnegie Quarry, but the one on display at CMNH is one of the largest. Douglass and his team excavated this 35-foot skeleton between 1913 and 1915. The mount was built in 1938. Although the specimen included a partial skull, the exhibit team swapped it with a cast of a more complete skull (also found in the Carnegie Quarry) from the collections of the University of Utah. This mount also includes casts of the arms of USNM 4734, an Allosaurus collected for O.C. Marsh.

Stegosaurus ungulatus – CM 11341

The CMNH Stegosaurus is a composite of several individuals excavated from the Carnegie Quarry between 1920 and 1922. Museum staff completed the 21 foot-long mount in 1940, using a skull cast from USNM 8612. Casts of this skeleton were distributed to several other museums at some point, one of which is on display at the University of Nebraska State Museum. Phil Fraley’s company remounted the CMNH original in 2007.

Carnegie Camarasaurus.

Carnegie Camarasaurus. Source

Camarasaurus lentus – CM 11338

This juvenile Camarasaurus is the most complete sauropod ever found. It is displayed as a relief mount almost exactly as it was discovered, with two exceptions. The left leg was swapped with a more complete one from another individual, and the tail was re-positioned to create a more aesthetically pleasing mount. Casts of this skeleton are displayed at museums throughout the United States, including Dinosaur National Monument, but the original is at CMNH. This specimen is also notable because its left scapula is preserved in its life position, making it a helpful model for skeletal reconstructions and exhibit mounts.

NMNH Camarasaurus. Photo by the author.

NMNH Camarasaurus. Photo by the author.

Camarasaurus lentus – USNM 13786

The second best Camarasaurus also comes from Carnegie Quarry, but it is a considerably larger individual. Only the tail and a few odds and ends were missing. CMNH kept the specimen for several years before trading it to USNM in 1933 for a set of Pliocene horse skeletons. Norman Boss prepared the specimen in full view of the public during the 1936 Texas Centennial Exposition – one of the first known examples of such an exhibit. The completed mount appeared at USNM in the 1950s, sporting the tail of another Camarasaurus. At over 30 feet long, this skeleton is one of the largest dinosaurs on display at the Smithsonian. Unfortunately, the death pose somewhat limits the effect. The Camarasaurus was taken off exhibit in late 2014 for conservation and remounting. When it returns, it will be standing on its feet for the first time in 150 million years, taking its rightful place as one of the museum’s most impressive dinosaurs.

DMNH Diplodocus. Source

DMNH Diplodocus. Source

Diplodocus longus – DMNH 1494

Since this Dipldodocus was found somewhat disarticulated, Douglass suggested that the carcass may have been twisted apart while rolling downstream. AMNH held on to this skeleton for some time before trading it to the Denver Museum of Nature and Science in 1936 for two mammoth skeletons. Preparator Phillip Reinheimer mounted the skeleton with the help of 40 workers assigned to the museum through the Works Progress Administration. Additional Diplodocus fossils collected by William DeWeese (actually the first dinosaur specimens acquired by the museum) were also used to complete the mount. The Diplodocus remained on view until 1989, when Ken Carpenter and others restored and remounted the sauropod, elevating its tail and making its neck sweep gracefully to the left. The improved mount has been on display since 1995.

CMNH Camptosaurus.

CMNH Camptosaurus. Historic photo from McGinnis 1982; modern photo source.

Camptosaurus aphanoecetes – CM 11337

Douglass found this controversial small ornithopod in 1922, and correctly matched it with an isolated leg several feet away. It was first identified as Camptosaurus medius, but in 2008 Ken Carpenter reassigned it to the new species C. aphanoecetes. A 2011 phylogenic study by Andrew McDonald moved this specimen to a new genus, Uteodon. Carpenter, however, asserts that McDonald’s analysis was based on an incorrectly associated Dryosaurus braincase.

CMNH staff assembled the fossils into a relief mount in 1940. The skull, hindfeet, and tail were all sculpted. During the 2007 renovation, the Phil Fraley Productions team extracted the fossils from the plaster slab, even managing to preserve the delicate ossified dorsal tendons. They then created a new, three-dimensional mount, which features a revised replica skull.

Modern photo by the author.

CMNH Dryosaurus. Historic photo from McGinnis 1982; modern photo by the author.

Dryosaurus altus – CM 3392

This Dryosaurus skeleton is the most complete of several collected at Dinosaur National Monument. The tail is missing, and given the completeness of the rest of the skeleton it may well have been destroyed when Douglass’s crew was blasting through rock to get to the bone layer. The Dryosaurus entered the CMNH collections in 1922, and was assembled as a 9 foot-long relief mount in 1940. In 2007, Fraley’s team removed the fossils from the plaster matrix, and just as they did with the Camptosaurus, constructed a standing mount. To date, this is the only mounted Dryosaurus specimen in the world. It is displayed alongside a juvenile Ceratosaurus cast acquired from Western Paleontological Laboratories.

National Museum of Natural History in Washington, DC.

NMNH Diplodocus. Photo by the author.

Diplodocus sp. – USNM 10865

The National Museum of Natural History’s Diplodocus was one of the last articulated skeletons removed from the Carnegie Quarry. When the CMNH crew closed up shop, Charles Gilmore of the Smithsonian moved in to recover one of the sauropod skeletons Douglass left behind. In 1923, Gilmore’s team excavated a partial Diplodocus, and also cherry-picked a few extra bones from an adjacent specimen. The process of mounting the skeleton at USNM took six years of continuous work, and Gilmore would later describe it as the most ambitious undertaking his department hadever attempted. The 70-foot Diplodocus mount was completed in 1931, and remained unchanged for more than 80 years. It was finally taken down in December 2014, and will return in a new pose in 2019.

Addendum: Mike Taylor recently called attention to a gorgeous map of the entire deposit prepared by Ken Carpenter, which was what prompted this post. Check it out here.

References

Carpenter, K. (2013). History, Sedimentology, and Taphonomy of the Carnegie Quarry, Dinosaur National Monument, Utah. Annals of the Carnegie Museum 81:3:153-232.

Dingus, L. (1996). Next of Kin: Great Fossils at the American Museum of Natural History. New York, NY: Rizzoli International Publications, Inc.

Gilmore, C.W. (1941). “A History of the Division of Vertebrate Paleontology in the United States National Museum.” Proceedings of the United States National Museum 90.

McGinnis, H.J. (1982). Carnegie’s Dinosaurs: A Comprehensive Guide to Dinosaur Hall at Carnegie Museum of Natural History, Carnegie Institute. Pittsburgh, PA: The Board of Trustees, Carnegie Institute.

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Filed under AMNH, CMNH, collections, dinosaurs, DMNS, exhibits, field work, fossil mounts, history of science, museums, NMNH, ornithopods, sauropods, theropods, thyreophorans

Real or cast? If only it were that simple!

Norman Boss Brachyceratops courtesy Smithsonian archives

Norman Boss assembles  a “Brachyceratops” mount. White bones and portions thereof are sculpted. Image courtesy of the Smithsonian Institution Archives.

Back in January, London’s Natural History Museum incited a flurry of debate when it announced that Dippy, the Diplodocus skeleton that has graced the museum’s entrance hall for decades, will soon be retired and replaced with a blue whale. One of the recurring arguments in favor of the change has been that Dippy is not an original specimen – it’s a cast, or as some commentators have called it, “a fake.” As I argued last month, referring to a fossil cast in this way is a flagrant misrepresentation. An excellent post by Liz Martin covers this in more detail – “fake” implies deception, or something invented outright. Fossil casts are nothing of the sort. They are exact replicas of fossils, and they could not exist without the original specimens they are based on.

Nevertheless, the idea that fossil mounts are either original bones or casts is a bit of a false dichotomy. I’m as guilty as anyone of propagating this myth – it’s a simple way to assuage the fears of museum visitors that the fossil skeletons on display aren’t real. The truth is that most mounts include some amount of straight-up sculpted material. After all, the fossilized remains of vertebrate animals, particularly large ones, are almost never found articulated or anywhere near complete. The specimens chosen for museum mounts are among the absolute best available, but even they are not perfect. For instance, the NHM Dippy (actually one of many) is mostly a cast of a single Diplodocus specimen held at the Carnegie Museum of Natural History, but the forelimbs were reconstructed. When the mount was assembled, no Diplodocus forelimb material of comparable size was available, so Arthur Coggeshall and colleagues sculpted some based on smaller specimens.

Sculpted feet

The sculpted feet of the AMNH Tyrannosaurus. Photo by the author.

From Hadrosaurus, the first mounted dinosaur skeleton, to modern reconstructions like Anzu, fossil mounts as we know them would not be possible without some amount of informed reconstruction. Take the iconic Tyrannosaurus rex mount at the American Museum of Natural History, assembled in 1915. The skeleton is a composite of two T. rex specimens, neither of which included any of the bones of the feet. Rather than creating a skeleton that stopped short at the ankles, Adam Herman sculpted a set of feet based on Allosaurus, another large meat-eating dinosaur. When Tyrannosaurus feet were eventually discovered, the allosaur-inspired feet turned out to be a little too bulky – tyrannosaurs actually had relatively long, gracile toes. But it’s not like T. rex turned out to have hooves or wheels. In most respects, from the basic three-toed arrangement to the shape and position of each individual bone, Hermann’s hypothesized tyrannosaur feet were spot-on. In fact, they were so close that the museum didn’t bother updating them when the skeleton was remounted in 1995.

The sculpted portions of fossil mounts aren’t wild speculation. They are very reasonable hypotheses based on a solid understanding of skeletal anatomy. As anatomist Georges Cuvier wrote in 1798:

Today comparative anatomy has reached such a point of perfection that, after inspecting a single bone, one can often determine the class, and sometimes even the genus of the animal to which it belonged…this is because the number, direction, and shape of the bones that compose each part of an animal’s body are always in a necessary relation to all the other parts, in such a way that – up to a point – one can infer the whole from any one of them and vice versa.

Cuvier’s principle of the correlation of parts – the idea that all backboned animals are built on the same basic body plan – is fundamental to the science of paleontology. If we have the right forelimb of an animal, we know that it had a mirror-image left forelimb. If we find a skeleton with it’s skull missing, we can still be confident that it had a head. What’s more, specialists can often recognize the group an animal belongs to (and sometimes the species) from just a few bones or teeth. Salamander vertebrae have a characteristic hourglass shape. Frog limb bones have “double-barreled” cavities in cross section. Marsupial teeth have a stylar shelf. New world monkeys have an extra premolar in each quadrant of the mouth. With enough specialized knowledge of related taxa, it is entirely possible to produce an educated reconstruction of most any animal from a minority of its skeleton.

How much is too much?

Argentinosaurus and Giganotosaurus at the Fernbank Museum of Natural History. Source

But as far as mounted skeletons in museums go, how far can we take this? Is it reasonable to build a standing mount when only 50% of the skeleton is definitively known? What about 30%? 10%? By bone count, that’s about the percentage of fossils ever found from the sauropod Argentinosaurus. And yet, the Fernbank Museum in Atlanta has a (rather spectacular) Argentinosaurus mount in its lobby. The whole thing is, of course, a fiberglass sculpture, dutifully based on better-known relatives. This mount is probably a fair reconstruction of what a complete Argentinosaurus skeleton would look like (although see this list of inaccuracies at Paleoking), but some still might consider it misleading. Your mileage may vary.

Museums generally do a good job labeling reconstructions. In particular, The Carnegie Museum and the Royal Ontario Museum are to be commended for posting charts alongside mounted skeletons that show which bones are original, which are casts, and which are reconstructions. In other cases, a little more transparency would not be unwelcome. For example, the four skulls below appear to include at least as much plaster reconstruction as bone, but they are all labeled as original specimens.

Photos by the author.

Four heavily-reconstructed fossil skulls at AMNH. Clockwise from top: Eryops, Indricotherium, Ophiacodon, and Triceratops. Photos by the author.

This is ultimately more of a philosophical question than a scientific one. Museum mounts, regardless of the amount of sculpted material, are usually well-supported reconstructions of the animal in question. If new information shows that a mount is wrong – as sometimes happens – staff are undoubtedly aware and will correct it as soon as funding and bureaucracy allow (granted, that can take decades). But as I’ve argued before, fossil mounts are unique among museum exhibits in that they are both the specimens and the interpretive context. They are hypotheses, but are presented (or at least understood) as straightforward truth. With this paradox in mind, how much is a museum ethically obligated to share about a mount’s creation? How can we do this without spurring visitors to use the dreaded f-word?

Comments are open, as always, and I’d be thrilled to hear what readers think.

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Filed under AMNH, anatomy, dinosaurs, fossil mounts, mammals, museums, NHM, reptiles, sauropods, science communication, theropods