Category Archives: reptiles

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.


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!


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

Beecher’s “Claosaurus”

Readers are likely aware that the Hadrosaurus Benjamin Waterhouse Hawkins created for the Academy of Natural Sciences was the first mounted dinosaur skeleton. It is less widely known, however, that this Hadrosaurus was a plaster facsimile, which included none of the actual fossils that inspired it. (edit: not quite, see comments). The title of first dinosaur mount composed of original fossils belongs to the Belgian Iguanodon assembled by Louis Dollo in 1891 (I should probably write about this eventually, but Fernanda Castano has an excellent account at Letters From Gondwana). So what was the first real fossil dinosaur mount on this side of the Atlantic? Glad you asked – that would be none other than the 1901 Edmontosaurus at the Peabody Museum of Natural History.

Edmontosaurus is surprisingly modern

The PMNH Edmontosaurus with Deinonychus and Centrosaurus. Photo by the author.

There are plenty of Edmontosaurus skeletons on display today, but the Yale mount is noteworthy because of its remarkably modern appearance. While the Hawkins Hadrosaurus and Dollo Iguanodon were upright tail-draggers, the Edmontosaurus could be mistaken for a mount constructed in the last quarter century. Its raised tail, horizontal posture, and energetic gait all reflect current thinking about dinosaur posture and locomotion. And yet, it was built at the turn of the century, back when paleontologists supposedly all thought of dinosaurs as lethargic lizards.

The Hawkins Hadrosarus and Dollo Iguanodon. Photos from

The Hawkins Hadrosarus and Dollo Iguanodon. Images from Paper Dinosaurs.

The scientist behind this mount was Charles Beecher. Born in Pennsylvania, Beecher studied at the University of Michigan before taking an Assistant of Paleontology position at Yale in 1888. He completed his PhD under Marsh, who apparently thought highly of him (and Marsh didn’t think highly of many people). Although his preferred research subjects were Paleozoic invertebrates, Beecher could be counted on to help prepare his mentor’s vast collection of dinosaur fossils, when needed. When Marsh died in 1899, Beecher succeeded him as the head of the Peabody Museum, and set himself the task of mounting one of the institution’s best dinosaur specimens for display.

Beecher selected YPM VP 2182 as the Peabody Museum’s first fossil mount because it was nearly complete and mostly articulated. Known to Marsh and Beecher as “Claosaurus” annectens*, this Edmontosaurus skeleton was collected in Wyoming by John Bell Hatcher (because of course it was). Beecher and assisting preparator Hugh Gibb attempted to preserve the fossils within their original matrix as much as possible. Since the specimen was somewhat laterally compressed, Beecher kept the right side mostly in situ and built up the left in high relief. The head and neck were technically never removed from their matrix block, but since the head was found curved under the body it had to be rotated into its life position. All told, only the right ribs, the corocoids, the final two-thirds of the tail, and some of the vertebral processes were reconstructed. No attempt was made to restore the ossified dorsal tendons, which were poorly preserved on this specimen.


Beecher’s Edmontosaurus, ca. 1917. Source

The complete mount is 13 feet tall and 29 feet long, its tail extending past the edge of the 27 foot slab. For a few years, it was the largest fossil mount ever built. The slab itself is made up of original matrix blocks sealed together with a manufactured surface created from plaster, resin, and ground Laramie Formation sandstone. It was assembled in four pieces secured to wooden frames. These were designed to be separated and moved with relative ease, although PMNH staff have yet to try.

According to Beecher, he imbued the Edmontosaurus with its lively pose in order to preserve the in situ orientation of the pelvis and left femur. It is worth quoting Beecher’s 1901 description of the mount in full:

“It is intended that this huge specimen should convey to the observer the impression of the rapid rush of a Mesozoic brute. The head is thrown up and turned outward. The jaws are slightly separated. The forearms are balancing the sway of the shoulders. The left hind leg is at the end of the forward stride and bears the entire weight of the animal. The right foot has completed a step and has just left the ground preparatory to the forward swing. The ponderous and powerful tail is lifted free and doubly curved so as to balance the weight and compensate for the swaying of the body and legs. The whole expression is one of action and the spectator with little effort may endow this creature with many of its living attributes.”

Much like the AMNH Gorgosaurus, the Yale Edmontosaurus demonstrates that early 20th century paleontologists’ supposed aversion to energetic and agile dinosaurs has been grossly overstated. Beecher saw Edmontosaurus as a powerful, active animal, and actually criticized the earlier reconstructions by Hawkins and Dollo. He correctly pointed out that the back-swept ischia of ornithopod dinosaurs would not allow room for the drooping tails they had reconstructed, and also noted that fossilized dinosaur trackways never show the mark of a dragging tail.

In the great hall of dinosaurs

Edmontosaurus as presently displayed in the Great Hall of Dinosaurs. Source

Beecher died suddenly in January of 1904, and the Edmontosaurus display ended up being one of his final professional accomplishments. Despite the relative dearth of dinosaur material available at the time, Beecher’s careful and impartial study of the available evidence allowed him to reconstruct this animal in a way that is still considered accurate 114 years later. Beecher’s work shows us that old research isn’t necessarily outmoded. Good science can come from any age and any source, if one only takes the time to look.

*Today, the genus Claosaurus is reserved for Claosaurus agilis from Kansas. The referred species annectens has since been placed in Thespesius, Trachodon, Anatosaurus, and now Edmontosaurus.


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

Jackson, R.T. 1904. Charles Emerson Beecher. The American Naturalist. Vol 38, No. 450.

Marsh, Othniel C. 1892. Restorations of Claosaurus and Ceratosaurus. American Journal of Science. Vol. 44, pp. 343-349.


Filed under dinosaurs, fossil mounts, history of science, museums, ornithopods, PMNH, reptiles

A Trio of Tyrants

The frentic search for North American dinosaur fossils in the late 19th and early 20th centuries can be divided into three phases. First came O.C. Marsh and E.D Cope, whose infamous rivalry resulted in literal trainloads of fossil material and laid the groundwork for our present understanding of dinosaur diversity. Next, teams sponsored by the newly-formed American, Carnegie, and Field museums returned to the same hunting grounds in the western interior to secure display-worthy specimens for their great halls of exhibition. The final phase was smaller in scale but yielded dinosaur specimens so spectacularly complete that most have gone unmatched to this day.

This third fossil rush occurred not in the United States but in Canada, along the cliff-like banks of Alberta’s Red Deer River. Fossil hunting in this region was pioneered in the late 1800s by George Dawson, Joseph Tyrell, and Lawrence Lambe, all working for the Canadian Geological Survey. This success did not go unnoticed by the the American Museum of Natural History’s Department of Vertebrate Paleontology. In 1910, the museum mounted an expedition led by Barnum Brown to the Red Deer River. Rather ingeniously, Brown’s team acquired a pair of 30-foot floating barges, which were used as mobile platforms from which they could excavate the steep river banks. The barges also served as floating campsites and a handy means of transportation in a region without reliable roads.The adventurous Brown was already a media favorite, and the publicity surrounding his Alberta expeditions only increased when the team started bringing back fully articulated and nearly complete dinosaur skeletons (including several with skin impressions).

Under pressure from constituents concerned that the Americans were hauling away so much of their natural heritage, the Canadian government formed its own team of fossil collectors in 1912. The new Canadian Geological Survey team was headed by independent fossil hunter Charles H. Sternberg (a veteran collector who had once worked for Cope) and his sons George, Levi, and Charles Jr. The Canadian and American teams worked in the same region for the next five field seasons. Their rivalry was usually good-natured, but on more than one occasion Brown saw fit to grumble about the Sternbergs’ ethics (never mind that he was the one permanently removing fossils from their country of origin).

Gorgosaurus at AMNH

Three tyrannosaurs mounted in relief at AMNH. Image courtesy of the AMNH Research Library.

All of this is so much preamble for the actual topic of this post – three remarkable Gorgosaurus skeletons* collected near the Red Deer River during the Canadian fossil rush. All three were eventually mounted in relief by AMNH preparator Peter Kaisen, and for a time they were displayed together in the Hall of Fossil Reptiles. These specimens are on the short list of most complete large theropod dinosaurs ever discovered, and in their day they provided researchers an unprecedented look at the physiology of these amazing animals. Nearly a century later, the three mounts are virtually unchanged. Locked behind glass for decades and largely inaccessible to researchers, the mounts themselves are now relics of a fascinating transitional period in the history of dinosaur studies.

*AMNH also recovered a fourth tyrannosaur during this period – Gorgeous George the Daspletosaurus.

As usual, a brief explanation of nomenclature is required. William Matthew and Barnum Brown originally described these specimens as Gorgosaurus, a genus that Dale Russell sank into Albertosaurus in 1970. Most specialists no longer support this synonymization, but the specimens at AMNH are still labeled as Albertosaurus.

Gorgosaurus libratus – USNM 12814


A recent photo of USNM 12812 from the ongoing renovation of the national fossil hall. Source

USNM 12814 (originally designated AMNH 5248) was excavated by Brown’s company in 1913 and prepared for display in 1918. Kaisen elected to recreate the death pose in which the Gorgosaurus was found, with its head swept backward over its body. All told, the finished mount included a skull, a complete set of cervical and dorsal vertebrae, complete forelimbs, and a single femur – the pelvis and the rest of the hindlimbs were filled in with casts from other specimens. Since the skeleton was mounted in relief, Kaisen simply painted the tail onto the backdrop.

After at least a dozen years on display at AMNH, the Gorgosaurus was traded to the National Museum of Natural History as part of a complicated deal between the two museums. While surveying fossil collections throughout the United States, Brown realized that a single Barosaurus skeleton from Dinosaur National Monument had been divided among three different institutions. NMNH had the neck and part of one forelimb, the Carnegie Museum had the tail, and the University of Utah had the rest. Between 1929 and 1933, Brown arranged a series of trades in order to unify the Barosaurus at AMNH. The Smithsonian in particular drove a hard bargain – the museum had already invested $3400 in preparing their Barosaurus section, and paleontology staff wanted a good return for their investment. Brown’s initial offer was the fully prepared and mounted Gorgosaurus. Although AMNH valued the field and prep time spent on the fossils at $4573, it was at that point a duplicate specimen taking up valuable space in their increasingly crowded exhibit hall.

NMNH dinosaur specialist Charles Gilmore confided in Brown that he was okay with this trade, but fellow Smithsonian paleontologist Alexander Wetmore wasn’t sold. For years, NMNH staff had been trying to acquire one of the many Moropus specimens AMNH had collected at the Agate Fossil Beds in Nebraska. NMNH had offered a variety of specimens to trade, even sending AMNH a set of brontothere skulls at one point, but AMNH was adamant the Moropus fossils could only be exchanged for cash. Brown really wanted that Barosaurus neck, so in January of 1933, he finally relented and offered the Smithsonian a largely complete Moropus in addition to the Gorgosaurus. Not long after, the Gorgosaurus relief mount found its way into the Hall of Extinct Monsters at NMNH.

Gorgosaurus sp. – AMNH 5458


A technician (probably Kaisen) adjusts the steel strap holding the femur in place. Source

Brown’s team found their second Gorgosaurus near Steveville, Alberta in 1914. Complete save for the left leg, right arm, and parts of the rib cage and tail, the mount was ready for display in May of 1921. At 24 feet long and 14 feet high, this was by far the largest relief mount at the museum. In fact, it was too big to fit through the workshop doorway in one piece, so Kaisen constructed it in eight sections that were sealed together in the exhibit hall. Each section had its own wooden frame for support, and the bones themselves were held in place with steel straps. The skull, jaw, and left forearm could be removed for individual study. This was unusual for the period (most contemporary fossil mounts were designed to be permanent) and speaks volumes about this specimen’s unique scientific value.

This mount is particularly notable for its awkward running pose. Directly contradicting many narratives of early 20th century paleontology, Matthew and Brown envisioned Gorgosaurus as an animal that “walked and ran much like a gigantic bird.” The AMNH team posed this mount after studying photos of bipedally running lizards, particularly the western tiger lizard*. However, Matthew and Brown noted that the dinosaur’s  limb proportions and range of motion more closely resemble a bird than a lizard, and adjusted the pose accordingly. They also advised a more conservative stride length to compensate for the animal’s considerable weight.

*Matthew and Brown do not provide a scientific name, and the common name “western tiger lizard” doesn’t seem to be used any more. Anyone know what it’s called today?

The final pose was a compromise between the elevated torso of a running lizard and the comparatively tight gait of a bird. It looks more than a little strange, but AMNH 5458 is certainly closer to our present understanding of theropod posture than most mounts of the era. Matthew and Brown’s interpretation of Gorgosaurus turned out to be ahead of its time. Some contemporary researchers, including Lawrence Lambe, declared the running pose to be highly improbable, and virtually all theropod mounts constructed over the next 60 years returned to the tail-dragging posture of the 1915 AMNH Tyrannosaurus.

Gorgosaurus sternbergi” – AMNH 5664

gorgo sternbergi

Gorgosaurus “sternbergi” as it was discovered and originally mounted. Source

The most complete tyrannosaur from the Red Deer River was not collected by the AMNH party, but by the Sternbergs. The elder Charles Sternberg discovered the specimen in 1917, entirely intact save for the left arm and the very end of the tail. In fact, this was the most complete large theropod ever found in North America until it was surpassed by yet another Gorgosaurus, TCM 2001.89.1. Sternberg first attempted to sell the specimen to the British Museum. They weren’t interested, but AMNH was. In 1918, the Department of Vertebrate Paleontology bought the skeleton for $2000, thus completing the tyrannosaur trio.

Matthew and Brown described AMNH 5664 as a new species – Gorgosaurus sternbergi. In their 1921 publication, they describe the skull as longer and shallower than other Gorgosaurus specimens, with rounder orbits. However, Brown and Matthew recognized that these could be juvenile characteristics, noting as well that the unfused pelvic bones were an indication of immaturity. As early as 1970, this specimen was suspected to be a juvenile Gorgosaurus (or Albertosaurus) libratus.

Kaisen prepared the relief mount in 1921, this time assisted by Carl Sorenson. The photo above shows the original version of this mount, with the tail projecting straight back from the body. This was how Sternberg discovered the skeleton, and Kaisen wanted to keep the death pose intact. In the 1950s, the tail was “corrected” to make it drag on the ground. Although the display has not been altered since, the revised tail posture is now considered inaccurate. Indeed, the vertebrae apparently had to be angled unnaturally to make the dragging tail work at all.

AMNH 5027 was restored and remounted in 1995.

The Gorgosaurus plaque mounts hide behind Tyrannosaurus rex at AMNH. Photo by the author.

All three Gorgosaurus specimens were first displayed in the cramped quarters of the Hall of Fossil Reptiles (now the Hall of Primitive Mammals) with the rest of the growing AMNH dinosaur collection (USNM 12814 and the tail of AMNH 5664 are barely visible in this photo). 5458 and 5664 moved to the newly opened Great Hall of Dinosaurs in 1922. They flanked the gallery’s rear doorway for 70 years before being moved to the Hall of Saurischian Dinosaurs in 1994. Meanwhile, the Gorgosaurus transferred to the Smithsonian first appeared in the Hall of Extinct Monsters in the 1940s, displayed behind glass on the north wall. It switched to the south side in 1962, and moved about 30 feet up the wall in 1981, where it could only be properly seen from the mezzanine ramp.

Aside from the aforementioned alternation to AMNH 5664’s tail, the Red Deer River Gorgosaurus trio has not been modified since they were first built. This may well change in the not-to-distant future. The NMNH crew is hard at work on a thorough renovation of the national fossil hall, dismantling and restoring all of the classic dinosaur mounts. Meanwhile, the current AMNH paleontology exhibits are now 20 years old, and will soon be due for a similar overhaul. Both institutions will need to decide whether or not to free the Gorgosaurus specimens from their plaster substrate. This would be an extremely difficult process, but not impossible – Phil Fraley Productions recently rebuilt the Carnegie Museum’s Corythosaurus, Dryosaurus, and Camptosaurus as free-standing mounts. Dismantling the relief mounts would give a new generation of scientists access to these important specimens, and it would allow for the skeletons to be given more accurate poses. In addition, a standing Gorgosaurus mount alongside either museum’s Tyrannosaurus rex would be both informative and awesome.

Nevertheless, remaking these mounts would also destroy significant historical context. The carefully restored death pose of USNM 12812 seems like something worth preserving, and the AMNH specimens represent an important transitional period in the history of dinosaur science. In the past, museums have often taken a “science marches on” approach when updating aging displays, but in these mounts might be unique enough in their current form to be left as-is. What do you think?


Carr, T.D. (1999). Craniofacial Ontogeny in Tyrannosauridae (Dinosauria, Coelurosauria). Journal of Vertebrate Paleontology 19: 497-520.

Colbert, E.H. (1968). Men and Dinosaurs: The Search in Field and Laboratory. New York, NY: E.P. Dutton & Co., Inc.

Gilmore, C.W. (1946). Notes on Recently Mounted Reptile Fossil Skeletons in the United States National Museum. Proceedings of the United States National Museum Vol. 96 No. 3196.

The Long Road to a Fossil Swap. Digging the Fossil Record, March 19, 2015.

Matthew, W.D. and Brown, B. (1923). Preliminary Notices of Skeletons and Skulls of Deinodontidae from the Cretaceous of Alberta. American Museum Noviates 89: 1-10.

Russell, D. (1970). Tyrannosaurs from the Late Cretaceous of western Canada. National Museum of Natural Science Publications in Palaeontology 1: 1–34.


Filed under AMNH, dinosaurs, field work, fossil mounts, history of science, museums, NMNH, reptiles, theropods

History of the AMNH Fossil Halls – Part 2

Start with History of the AMNH Fossil Halls – Part 1.

During his leadership of the American Museum of Natural History’s Department of Vertebrate Paleontology and later, the museum at large, Henry Osborn oversaw an unprecedented expansion of the institution’s paleontology exhibits. As fossils poured in from the Department’s international collecting expeditions, these displays expanded into five separate galleries on the museum’s fourth floor. During the first two decades of the 20th century, AMNH staff was installing newly prepared and mounted specimens every single year. In it’s heyday, AMNH was the undisputed center of American vertebrate paleontology. The increasingly marginal role of descriptive natural history in the greater field of biology at this time made the scale of Osborn’s program all the more impressive.

Nevertheless, this golden age of fossil exhibits would not last forever. Osborn supported the expensive expeditions and monumental displays through his personal connections with wealthy benefactors. The combination of the Great Depression and Osborn’s death in 1933 all but eliminated this source of income, and the museum had to scale back its activities considerably. In 1942, the Department of Vertebrate Paleontology was dissolved. Paleontology work continued under the Department of Geology, but with only a fraction of its former staff and budget.

Phase IV: 1940 – 1955


In the post-Osborn era, responsibility for the fourth floor exhibits deservedly transferred to Barnum Brown. Indeed, Brown’s adventures as a swashbuckling fossil hunter not only brought him personal fame, but made the museum’s world-class paleontology exhibits what they were. Of the 36 dinosaurs on display by 1939, no less than 27 had been discovered by Brown. Most of these iconic finds were made in his 20s and 30s, but Brown nevertheless remained at AMNH for most of his life. Even after officially retiring in 1943, Brown still frequented the museum, often giving spontaneous personal tours of the exhibits.

brown's jurassic hall

Brown’s Jurassic Hall, around 1940. Photo from Dingus 1996.

In 1932, the architectural firm Trowbridge and Livingston completed the 13th building in the AMNH complex. This meant that for the first time, the paleontology exhibits formed a complete circuit, an arrangement that persists to this day. Brown opted to spread the dinosaurs into two halls, making the new space the Jurassic Hall and converting the Osborn-era Great Hall of Dinosaurs into the Cretaceous Hall. Several existing fossil mounts had to be moved as a result, including the massive “Brontosaurus.”  Eyeballing the widths of the doorways and corridors separating the present day Hall of Saurischian Dinosaurs (formerly the Jurassic Hall) and Hall of Ornithiscian Dinosaurs (formerly the Cretaceous Hall and Great Hall of Dinosaurs), it’s difficult to imagine how museum staff could have moved the 66-foot sauropod in one piece. This photograph suggests that the skeleton was divided into several sections, which then had to be brought down the freight elevator on one side of museum and carted around to an elevator on the other side. This would be the third and final position for the “Brontosaurus” – even when the mount was updated  in 1995, preparators left the torso and legs in place.

brown's cretaceous hall

Brown’s Cretaceous Hall, around 1939. Photo courtesy of the AMNH Research Library.

The 1930s and 40s saw a number of new dinosaur mounts added to the displays, nearly all of which were discovered by Brown. The new Jurassic Hall gained a Stegosaurus and Tenontosaurus (oddly not a Jurassic dinosaur), and the Cretaceous Hall gained Brown’s astonishingly intact CentrosaurusCorythosaurus, and Styracosaurus from Alberta.

Phase V: 1956 – 1990


Edwin Colbert joined AMNH in 1930 as Osborn’s assistant (he called this “a time of experiences and incidents,” whatever that means). Eventually rising to Curator of Vertebrate Paleontology, Colbert was one of only a handful of mid-century researchers studying dinosaurs. He is also notable for his public outreach – in collaboration with his spouse, Margaret Colbert, he wrote more than 20 popular books about paleontology.

In 1953, Colbert worked with exhibit specialist Katharine Beneker to redesign the Jurassic and Cretaceous Halls. The Jurassic Hall received the more dramatic aesthetic makeover – windows were covered up to create a “black box” effect, while the dinosaur mounts were illuminated dramatically from above and below. Surprisingly, the most significant addition to this space wasn’t a standing mount, but a trace fossil. Exhibit developers incorporated several slabs of sauropod tracks (collected at the Paluxy River in Texas by Roland T. Bird) into the central pedestal, as though left behind by the “Brontosaurus.” Cemented together, the slabs weighed 22 tons – apparently nobody expected that they would ever need to be moved. The fossil fish alcove, formerly part of the 1905 Hall of Fossil Reptiles, also found a home in this space.

In stark contrast to the Charles Knight oil and watercolor murals commissioned by Osborn, Colbert elected to decorate the Jurassic Hall with a series of understated chalk drawings. Joseph Guerry created the artwork, which was then projected onto the walls and traced in chalk. The initial plan was to paint over the chalk outlines, but Colbert enjoyed the blackboard-like look and left them as they were. The exhibit team didn’t even add fixative, since it would have turned the lines an unpleasant yellow.

Jurassic hall colbert. Photo from Dingus 1996.

The Jurassic – or Brontosaur – Hall opened in 1953. Photo from Dingus 1996.

Architectural modifications to the Cretaceous Hall were minimal, although the standing dinosaur mounts were all clustered on a single platform. Interestingly, both the National Museum of Natural History and the Peabody Museum of Natural History would arrange their dinosaurs in precisely the same way within the decade. While it’s possible that these museums were copying AMNH, this similarity is probably a reflection of the transition to more holistic natural history displays that was occurring in museums nationwide. Rather than displaying specimens individually, exhibit designers in the 1950s and 60s began to arrange them in meaningful ways – for example, grouping animals with a shared habitat. The Cretaceous Hall also gained some new specimens, including an array of Protoceratops skulls recovered during the Central Asiatic Expeditions. Signs and labels were updated with more approachable language, once again reflecting contemporary museum theory.

The Cretaceous – or Tyrannosaur – Hall opened in 1954. Photo courtesy of the AMNH Research Library.

Meanwhile, some of the oldest AMNH fossil exhibits were retired and replaced during this period. In 1961, the classic geology hall – the oldest exhibit on the fourth floor – became the research library and was closed to regular museum visitors. Its spiritual successor was the new Earth History exhibit, which replaced Osborn’s Hall of the Age of Man. Around the same time, George Gaylord Simpson curated what was colloquially known as the “Sloth Hall.” Occupying the space that was once the Hall of Fossil Reptiles, this exhibit featured ground sloths and glyptodonts, plus a sizable display demonstrating how fossils are collected and prepared. Only the Hall of Fossil Mammals remained ostensibly untouched during this wave of modernization.

The Hall of Advanced Mammals in 1982 – some sections were boarded up but remaining exhibits were virtually unchanged from the turn of the century. Photo courtesy of the AMNH Research Library.

The 1950s and 60s iterations of the AMNH fossil halls endured for 30 years, making them the longest-lasting versions to date. Displays like the “Brontosaurus” and Tyrannosaurus became immutable symbols for the institution, visited again and again by generations of museum-goers. However, time gradually took its toll. A large section of the Hall of Fossil Mammals was boarded up, since museum staff had removed so many specimens for study or conservation. Railings were eventually added to the Jurassic Hall, because it was too tempting for visitors to join the dinosaurs on the platform, Ke$ha-style.

The Brontosaur Hall in 1988. Photo courtesy of the AMNH Research Library.

Most importantly, the exhibit content became increasingly out-of-date with each passing year. This obsolescence permeated nearly every aspect of the exhibits, from the discussion of the dinosaurs’ extinction to the drab, earth-tone aesthetics. However, the most visibly antiquated elements were the fossil mounts themselves. A new wave of dinosaur research demonstrated that these animals had been active and socially sophisticated, a far cry from the the coldblooded tail-draggers that populated the galleries. AMNH had once been the center of American paleontology, but by the late 1980s its dated displays were lagging far behind newer museums.

Phase VI: 1995 – Present


Between 1987 and 1995, Lowell Dingus coordinated a comprehensive, $44 million renovation of the AMNH fossil exhibits (previously discussed here and here). The original plan was to renovate only the Hall of Fossil Mammals, since it had remained largely unaltered since 1895. Within a year, however, the project had expanded to encompass all six halls on the fourth floor, telling the entire story of vertebrate evolution. Two primary goals originated very early in the planning process. First, the “walk through time” layout would be replaced with one rooted in phylogenetic classification. The cladistic methodology for tracing organisms’ evolutionary history became the central theme that unified the new exhibits. This required a fairly substantial reorganization of existing specimens. The mammals could remain in the same two halls, but the denizens of the Jurassic and Cretaceous halls had to be rearranged to feature Saurischian and Ornithiscian dinosaurs, respectively. Meanwhile, the research library moved to a new location to make way for the Hall of Vertebrate Origins.

Advanced Mammals

The Hall of Advanced Mammals was the first renovated exhibit opened to the public. Photo by the author.

The second major goal was to restore the original architecture in each hall, ensuring that both the historic specimens and the spaces they occupied would come “as close to their original grandeur as possible” (Dingus 2006). In many cases original architecture elements – such as the moulded ceilings – were still intact behind panels that had been installed over them. These features were painstakingly restored, or when necessary, recreated. Classic decorative elements, from the colonnades to the elegant chandeliers, were reintroduced.

Apatosaurus remount

The updated Apatosaurus in the Hall of Saurischian Dinosaurs. Photo by the author.

The vast majority of the fossil mounts in the renovated exhibits had already been on display for years. Among the classic mounts, only the two most iconic displays were completely overhauled. The restoration of Apatosaurus (formerly “Brontosaurus”) took more than a year. A conservation team led by Jeanne Kelly worked from a temporary wooden scaffold, filling cracks in the aging fossils with epoxy and securing loose joints on the armature. The mount’s torso and legs remained in place throughout the process, but the neck and tail were dismantled and remounted by Phil Fraley’s exhibit company. In addition to a new head, the revised Apatosaurus gained several caudal and cervical vertebrae, extending its total length to 88 feet. Remounting the Tyrannosaurus rex was even more difficult, because the fossils were so fragile. Once again, Phil Fraley was responsible for disassembling and reposing the skeleton. The T. rex now sports a more accurate horizontal posture, and its weight is supported by steel cables extending from the ceiling.

The new fossil mounts are easily recognized by their dynamic poses. In the Hall of Vertebrate Origins, the amphibian “Buettneria” (now Koskinodon) assumes a diving pose, while a Prestosuchus charges with its tail aloft. Among the dinosaurs, a new Deinonychus mount (assembled in part from previously-unidentified historic material) is posed in mid-leap. Finally, the dog-like Amphicyon chases the tiny antelope Ramoceros in the Hall of Advanced Mammals.

hall of ver

In the Hall of Vertebrate Origins, a new Koskinodon mount represents the vertebrates’ critical transition to terrestrial life. Photo by the author.

The AMNH fossil halls represent one of the most exhaustively complete fossil collections in the world, but these exhibits ultimately tell two stories. On one hand, we have the story represented by the fossils themselves. The exhibit is an extended genealogy, tracing our origins across 500 million years of deep time. On the other hand, we have the museum’s history, which highlights both the praiseworthy and the ugly sides of 20th century science. It reminds us where our society has been and where it needs to go. Both stories are relevant to each and every person passing through these halls, and laudably, the latest renovation highlights both.


Colbert, E.H. (1958). Chalk Murals. Curator 4:10-16.

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

Norell, M, Gaffney, E, and Dingus, L. (1995). Discovering Dinosaurs in the American Museum of Natural History. New York, NY: Alfred A. Knopf, Inc.


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

History of the AMNH Fossil Halls – Part 1

Much of what I write for this site starts with an attempt to find one reference or another, only to discover that it does not exist online. This time, I was curious how many times the American Museum of Natural History paleontology halls had been renovated, but I quickly found that there was no simple answer.  Unlike the fossil exhibits at the National Museum of Natural History, which have occupied the same large hall since the building opened, the AMNH counterparts have been moving and growing for more than 120 years. The museum expanded organically, eventually encompassing 27 interconnected buildings. And as its footprint grew, the paleontology exhibits grew with it.

The following is my attempt to make sense of the fourth floor exhibit halls’ convoluted history. I’ve divided it into six phases, although this should only be considered a rudimentary outline. Many specimens were added and removed during each phase, particularly during the period of frantic expansion in the early 20th century. At the very least, however, this should be enough to contextualize most of the historic photos made available by the AMNH Research Library. As with my NMNH posts, please note that I will not be discussing field expeditions or scientific discoveries by museum staff, as these topics are well-explored elsewhere. My focus here is solely on the public-facing exhibits, and the people who created them.

Phase I: 1874 – 1904


AMNH was founded in 1869, although the first buildings in Manhattan Square did not begin construction until 1874. The original structure was designed by architect Calvert Vaux. Since electric lights were not yet available, Vaux created exhibit spaces that maximized the impact of natural lighting. Large windows were divided into slits that paralleled rows of glass display cabinets. The sun would shine through the windows and directly into the cabinets, illuminating the specimens within. When the museum first opened, the single exhibit hall on the fourth floor was dedicated to geology specimens. While this space mostly housed rocks, minerals, and small fossils, a handful of mounted skeletons stood among the cabinets. Early acquisitions included a moa and the Pleistocene deer Megaloceros, shown below.

geology hall with moa

Geology Hall, before 1887. Photo from Dingus 1996.

Things changed radically shortly after Henry Osborn was hired in 1891. As a paleontologist, Osborn emerged from Princeton riding the crest of a wave of goodwill his discipline had enjoyed for most of the 19th century. Paleontology was the darling of American science, and one man in particular, O.C. Marsh of Yale, received generous federal funding to find and describe new fossils from the western interior. In the 1880s, however, an economy-minded Congress pulled that funding. Meanwhile, the rise of experimental biology led to the marginalization of descriptive natural history, including paleontology. The next generation of paleontologists needed a new home for their work, and they found it in museums. AMNH was one of several new museums backed by wealthy benefactors with an interest in public education. These benefactors gravitated toward paleontology because, as Ronald Rainger put it, fossils are “rare, valuable, and visible.” The skeletons of extinct monsters were huge and sensational, and naturally complimented the grandiose neoclassical halls of the nascent museums. But while the paleontology programs at institutions like the Carnegie Museum and the Field Museum were quite respectable, they all were overshadowed by Osborn’s Department of Vertebrate Paleontology at AMNH.  Osborn’s goal was to make AMNH the center of American vertebrate paleontology in the post-Marsh world, and by most any measure he succeeded.

Hall of Fossil Mammals, around 1906.

Hall of Fossil Mammals, around 1906. Photo from Dingus 1996.

The next Phase I exhibit was the Hall of Fossil Mammals, which opened to the public in 1895. Osborn’s research was focused on Cenozoic mammals, especially brontotheres, and he tasked his department with assembling a suitably impressive collection. Some of the fossils on display were acquired in an 1897 purchase of Edward Cope’s personal collection. Many others were collected by AMNH staff in the Big Horn Basin of Wyoming. Among these in-house finds was the famous (and famously misleading) series of fossil horses, most of which were found and prepared by William Matthew. The largest and most captivating mounted skeleton on view was the Warren mastodon. Discovered in 1845 in a bog near Newburgh, New York, this specimen was the first complete mastodon ever found. It was initially described and displayed by Boston-based anatomist John Warren, but Osborn convinced J.P. Morgan to buy it for AMNH in 1906.

Aside from a few shuffled mounts (including the aforementioned mastodon, which seems to have been in nearly every room on the fourth floor), the Hall of Fossil Mammals remained mostly intact for the duration of the 20th century. Shortly after it was completed, the Department of Vertebrate Paleontology shifted its focus to dinosaurs. The mammals were only the star attractions for a few short years, but this display would nevertheless endure in its original form for generations.

“Ancestry of Man” case in the Hall of the Age of Man, 1929. Photo courtesy of the AMNH Research Library.

At this point, it is crucial to mention that Osborn was an objectively lousy scientist, and that much of his work was motivated by a bigoted personal agenda.  He subscribed to an inaccurate orthogenetic (or as he called it, “aristogenetic”) interpretation of evolution, professing that all life forms had their place in a natural hierarchy. According to Osborn, people of Anglo-Saxon and Scandinavian ancestry were the pinnacle of existence, and he endeavored to turn his flagrantly racist beliefs into public knowledge by way of his exhibits. Nowhere is this clearer than the Hall of the Age of Man, which opened around 1900. This hall included a range of extinct animals that coexisted with early humans, but the central cases were dedicated to Osborn’s unorthodox narrative of human evolution. Hominid fossils were co-opted to illustrate Osborn’s unfounded view that modern human races were evolutionarily distinct, and to communicate his support for eugenics and racial purity. Osborn’s agenda was supported by many of the aristocratic elite that funded the museum, but apparently few of the AMNH research staff endorsed it. Margaret Mead in particular was highly critical of Osborn’s views, and especially his influence over public-facing interpretation.

Phase II: 1905 – 1920


Edit: The map above should read “Invertebrate Fossils and Minerals.” 

For all of Osborn’s bigotry and bad science, it’s difficult to imagine the modern museum field without his influence. He was very good at marketing himself and his paleontology program, and he knew how to put on a show that would attract visitors in droves. Osborn heightened the standards for public exhibitions, investing in lifelike habitat dioramas of taxidermy animals and spectacular fossil mounts in order to make science exciting for a wide audience. Osborn’s devotion to storytelling and drama in the exhibits he curated brought millions of visitors to AMNH and defined public expectations for what museums should offer.

In 1906, Osborn became the fourth president of AMNH, and he oversaw its most rapid period of expansion. As president, he tripled municipal funding for the museum from New York City, and gained plenty more through his connections with wealthy potential donors. Much of this income was funneled into the Department of Vertebrate Paleontology’s famous dinosaur collecting expeditions, in which fossil hunters like Barnum Brown and Walter Granger earned fame and notoriety. However, the pioneering work on fossil preparation and mounting at AMNH was also significant. While many peer institutions were assembling and exhibiting new dinosaur mounts during this period, none matched the output or ambition of AMNH. With the sheer quantity of fossils coming in and institutional pressure to mount them for display as quickly as possible, chief preparator Adam Hermann had no choice but to modernize and professionalize his craft. Hermann developed a sophisticated prep lab with overhead tracks for hoisting heavy fossils, as well as electric and pnuematic hook-ups for power tools. Techniques like sand-blasting, acid preparation, and on-site metalworking developed by Hermann are still standard practice today.

trachodon crowded reptile hall

“Trachodon” pair in the Hall of Fossil Reptiles. Photo from Dingus 1996.

Dinosaurs take up a lot of space, and to accommodate them, a new gallery was opened on the far end of the Hall of Fossil Mammals. This Hall of Fossil Reptiles debuted in 1905 with “Brontosaurus” – the first mounted sauropod ever built – as its centerpiece. Actually a composite of four individuals and many sculpted elements (including the way-off-the-mark head), the “Brontosaurus” took Hermann’s team the better part of six years to construct. After that, the Hall of Fossil Reptiles filled with new dinosaur mounts very quickly, cementing the repuation of AMNH as the place to see dinosaurs. In 1906, Hermann added the “Trachodon” pair. The standing individual came from the Cope collection, but the crouching specimen was excavated that very year by Barnum Brown. The Allosaurus was also a Cope specimen, but apparently the 19th century paleontologist had never unpacked or inspected it. Several years passed before Hermann’s team discovered that the skeleton was remarkably complete, although it was missing a skull. The Allosaurus fossils were mounted in 1908, posed as though feeding on a set of Apatosaurus vertebrae.

crowded reptile hall

Tyrannosaurus stands with Allosaurus and “Brontosaurus” in the increasingly crowded Hall of Fossil Reptiles. Photo from Dingus 1996.

Arguably the most important mount added during the early 20th century mounting spree was the Tyrannosaurus rex. This specimen is no less than an icon, and has been a destination attraction in New York for longer than the Empire State Building. When the Tyrannosaurus was unveiled in 1915, it was a sensation, akin to mythical dragon made real. For a generation, AMNH was the only place in the world where visitors could stand in the presence of a T. rex, and to this day the image of the classic mount is quintessential to both paleontology and museums in general. For example, you may recognize it from the cover of a certain Michael Crichton novel.

Phase III: 1921 – 1939


In 1922, the 9th building in the AMNH complex was completed, and the paleontology exhibits expanded into what Osborn called the “Great Hall of Dinosaurs.” The largest dinosaur mounts – including Tyrannosaurus, “Brontosaurus”, “Trachodon”, and Allosaurus – were moved from the comparatively cramped Hall of Fossil Reptiles into this new space. The extra breathing room allowed for the mounts to be clustered into Jurassic and Cretaceous areas on opposite sides of the room. There were also a few new skeletons, including Leptoceratops, Thescelosaurus, and most significantly, Triceratops.

brontosaurus in great dinosaur hall

“Brontosaurus” in the Great Dinosaur Hall, around 1927. Photo courtesy of the AMNH Research Library.

Meanwhile, AMNH fossil collecting efforts had moved from the American West to Mongolia. The primary goal of Roy Chapman Andrews’ Central Asiatic Expeditions was to find evidence for Osborn’s pseudoscientific ideas about human ancestry, but no such remains were found. Instead, the expedition returned a wealth of new dinosaur fossils, including the first dinosaur nests ever found. Dispatches from the field also drummed up considerable publicity for the New York museum.

great dinosaur hall

Tyrannosaurus and Triceratops in the Great Dinosaur Hall, around 1927. Photo courtesy of the AMNH Research Library.

Osborn’s iron-fisted reign over American paleontology lasted until his death in 1933. Unfortunately for the Department of Vertebrate Paleontology, Osborn’s activities depended heavily on personal relationships with private donors. With Osborn out of the picture (and the Great Depression at its bottom), those donations dried up. Meanwhile, Osborn’s good standing in the scientific community had begun to wane, and his unorthodox anthropological ideas became something of a joke. The results of internal investigations into Osborn’s less-than-legitimate use of funds and favors during his time as president did not help matters. In 1942 the Department of Vertebrate Paleontology was dissolved. Paleontology work was folded into the Department of Geology with a much smaller budget and fewer staff. The Osborn-era fossil displays at AMNH remained largely unaltered in the years that followed, but only because of the lack of staff time, money, and interest.

Next week, we’ll wrap up this timeline, passing through the era of Edwin Colbert and into the present day. Stay tuned!


Brinkman, P.D. (2009). Dinosaurs, Museums, and the Modernization of American Fossil Preparation at the Turn of the 20th Century. Fossil Preparation: Proceedings of the First Annual Fossil Preparation and Collections Symposium 21-34.

Brinkman, P.D. (2010). The Second Jurassic Dinosaur Rush: Museums and Paleontology in America at the Turn of the 20th Century. Chicago, IL: The University of Chicago Press.

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

Haraway, D. (1984). Teddy Bear Patriarchy: Taxidermy in the Garden of Eden, New York City, 1908-1936. Social Text 11:20-64.

Hermann, A. (1909). Modern Laboratory Methods in Vertebrate Paleontology. Bulletin of the American Museum of Natural History 56:283-331.

Osborn, H.F. (1921). The Hall of the Age of Man in the American Museum. Nature 107:236-240.

Rainger, R. (1991). An Agenda for Antiquity: Henry Fairfield Osborn and Vertebrate Paleontology at the American Museum of Natural History, 1890-1935. Tuscaloosa, AL: The University of Alabama Press.


Filed under AMNH, anthropology, dinosaurs, exhibits, fossil mounts, mammals, museums, reptiles

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.


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

Framing Fossil Exhibits: Phylogeny

This is the third part of an on-again, off-again series about organizational and interpretive approaches in large-scale paleontology exhibits (see the introduction and walk through time entries). This time, I’ll be discussing exhibits arranged according to phylogenetics – that is, the evolutionary relationships among living things. Natural history museums have displayed specimens according to their place on the tree of life since the days of Charles Wilson Peale, and more than any other organizational scheme, phylogeny is the way biologists think about the living world. Perhaps unsurprisingly, this arrangement was more common in the past, when exhibits were typically designed by and for experts. Examples of these old-school displays include the fossil mammal gallery at the Peabody Museum of Natural History and the paleontology halls at the University of Kansas Natural History Museum (neither has been thoroughly overhauled since the 1950s).

peabody mammals

The jargon-heavy signage in the Peabody Museum’s classic fossil mammal exhibit is probably ignored by most visitors. Photo by the author.

Modern natural history museums rarely attempt phylogenetic exhibits. In vertebrate paleontology, an understanding of the evolutionary relationships of animals as identified via minute anatomical details is fundamental to our science. However, most people simply don’t think about the world in this way. For example, I was halfway through my first semester teaching an undergraduate anatomy course when I realized that most of the class didn’t really understand what a mammal is. The students were familiar with the word “mammal” and could provide some examples, but they couldn’t articulate what sets mammals apart from other animals, and the relationship of mammals to other vertebrates within the tree of life was all new to them. It’s easy to forget that even the most basic elements of evolutionary classification are specialized knowledge, even among biology students.

Describing the history of life on Earth chronologically is relatively easy – museum visitors intuitively understand the forward progression of time. But scientific classification (as opposed to colloquial categorization) requires a lot of explanation up front, and it’s easy to overwhelm an audience with jargon. While not impossible (see Neil Shubin’s masterful Your Inner Fish), it is very difficult to explain phylogeny to a general audience in a relatable and approachable way.

In 1995, the American Museum of Natural History attempted to do just that with the most recent renovation of its historic 4th floor fossil halls. This evolutionary arrangement was a major change for AMNH, since this space had a “walk through time” layout for most of the 20th century. In the accompanying book Discovering Dinosaurs in the American Museum of Natural History, curators Norell, Gaffney, and Dingus explain that phylogenetics (and the cladistic methodology in particular) is the only way to approach the study of prehistoric life in an objective way. Patterns of evolutionary relationships revealed by cladistic analyses are hard evidence in a field of study traditionally characterized by idle speculation. Norell and colleagues argue that the new exhibit arrangement shows visitors the credibility and scientific rigor behind modern paleontology.

4th floor of AMNH.

Map of the fossil halls on the 4th floor of AMNH. Source

Communicating the rigorous and trustworthy nature of scientific conclusions is a worthy goal, and the choice to ground the AMNH exhibit in this way seems almost prophetic given the litany of speculation-heavy paleontology “documentaries” that have proliferated in the years since it opened. Scientific rigor is definitely a running theme here – sign after sign explains that popularly depicted dinosaur behaviors like parental care and pack-hunting are largely untestable speculation. To a degree, this label copy takes the fun out of an undeniably fun subject, but I can appreciate the effort to legitimize paleontological science in the public eye. Overall, the AMNH exhibits represent an attempt to train visitors to look at fossils the way scientists do, and the phylogenetic layout is central to that goal.

In the exhibit, visitors are meant to walk through a cladogram of chordates. You’ll pass through large halls dedicated to broad groups like saurischian dinosaurs and advanced mammals, while visiting smaller cul-de-sacs that  represent narrower clades like ornithomimids and testudines. A central black path guides you through the evolution of life, and centrally-situated pillars along your route identify major evolutionary innovations, such as jaws or the ability to reproduce on land. The insanely comprehensive vertebrate fossil collections at AMNH make this institution uniquely capable of putting so much diversity on display (although non-tetrapods are woefully underrepresented). Meanwhile, an open floor plan allows you to spend as much or as little time in each area as you wish, and ample natural lighting goes a long way toward making it possible to study specimens in detail.

follow the path for now

Pillars mark major evolutionary milestones in the Hall of Vertebrate Origins. Photo by the author.

path disappears among dinosaurs

The evolutionary pathway becomes considerably less obvious among the dinosaurs. Photo by the author.

Nevertheless, I agree with Brian Switek that the AMNH fossil halls don’t do the best job communicating the story of vertebrate evolution to their core audience. The underlying purpose of any exhibit structure is to provide meaning and context for objects – to help visitors see them as more than neat things to look at. According to visitor surveys, the default mode of understanding for most people passing through a paleontology exhibit is what I’ve been calling “dinosaur pageantry.” After seeing the exhibit, most visitors will recall a list of cool skeletons they saw. A few might consider which ones are meat-eaters and which ones are plant-eaters, but without further prompting that’s all we can usually expect from non-specialists. It’s the museum’s job to give visitors the intellectual tools to contextualize those fossils in a more sophisticated way, but there’s a fine line to walk. Provide too little information and nobody learns anything, but provide too much and the content is ignored. Unfortunately, the AMNH exhibits fall into the “overkill” category.

As discussed, phylogeny is complicated, often counter-intuitive, and largely unfamiliar to many visitors. To overcome this, the AMNH designers rely on a fairly long orientation film, which introduces the concept of categorizing organisms based on shared derived characteristics. There are a few problems with this. First there’s the film itself, which dives right into the traits that characterize different groups – like the stirrup-shaped stapes of derived mammals and the temporal fenestrae of archosaurs – without explaining why these traits are significant. To a layperson, these probably seem like really inconsequential things to hang a whole group on. The video also presents a cladogram of vertebrates without explaining how to read it. As Torrens and Barahona demonstrate, interpreting a phylogenetic tree is a specialized skill that many natural history museum visitors lack. Second, I saw no incentive or instruction to actually start my visit to the 4th floor in the orientation hall. There are no less than four entrances to the fossil exhibits, so many visitors won’t know there is an orientation film (I sure didn’t) until they’re halfway through the galleries. Finally, there’s the reliance on media in general: do we really want visitors to spend even a portion of their time in an exhibit full of real fossils watching a video in a darkened room? Telling visitors what to think in a narrated video is easy, but it’s not nearly as meaningful as showing them the same concept with specimens (or better yet, coaxing them to reach conclusions themselves).

Hall of Saurischian Dinosaurs, American Museum of Natural History. Photo by the author.

Iconic mounts in the Hall of Saurischian Dinosaurs are iconic. Photo by the author.

Within the actual fossil halls, interpretation remains stubbornly unapproachable. For example, the sign introducing proboscidians tells visitors that this group is defined primarily by eye sockets located near the snout. An observant visitor might wonder why scientists rely on such an obscure detail, as opposed to the obvious trunks and tusks. There’s a good teaching moment there concerning why some characteristics might face more selection pressure (and thus change more radically) than others, but instead visitors are only offered esoteric statements. Relatedly, the exhibit does little to prioritize information. Most label text is quite small, and there’s a lot of it. Compare this to Evolving Planet at the Field Museum, where there is a clear hierarchy of headings and sub-headings. Visitors can read the main point of a display without even stopping, and parents can quickly find relevant information to answer their charges’ questions (rather than making something up).

Evolving Planet also compares favorably to the AMNH fossil halls in its informative aesthetics and spatial logic. At FMNH, walls and signs in each section are distinctly color-coded, making transitions obvious and intuitive. Likewise, consistent iconography  – such as the mass extinction zones – helps visitors match recurring themes and topics throughout the exhibit. AMNH, in contrast, has a uniform glass and white-walled Apple Store aesthetic. It’s visually appealing, but doesn’t do much to help visitors navigate the space in a meaningful way.

edentates aren't real

Phylogenetic interpretations change quickly – Edentata is no longer considered a natural group. Photo by the author.

The phylogenetic layout introduces a number of other unique interpretive challenges. Since there is no temporal axis,  it’s often unclear whether the lineage in a particular cul-de-sac cluster went extinct, continued on, or gave rise to another group elsewhere in the exhibit. Visitors that want to know which animals lived contemporaneously are out of luck. Meanwhile, the exhibit sometimes uses modern animal skeletons to fill out displays where fossil examples are limited, such as bats and primates. While these are labeled, the text is too small to be seen from a distance. The evolutionary organization is also burdened by the fact that phylogenetics is a fast-moving and often changing field of study. While the order of geologic time periods will never change, the 20 year-old displays at AMNH are already out of date in several details. For example, there is a cul-de-sac devoted to edentates, which is now considered polyphyletic, and a cladogram in the Hall of Saurischian Dinosaurs incorrectly places tyrannosaurids among the carnosaurs.

Cows and broken videos

Glass architecture lets visitors see through displays and get a sense of what lies beyond. Photo by the author.

Neat comparison of mammal teeth. Too bad there's no obvious label.

This display is a great example of the diversity in mammal teeth, but it’s a confusing centerpiece for the Hall of Primitive Mammals. Photo by the author.

The AMNH fossil exhibits excel in many respects, chiefly in the amazing diversity and quantity of specimens on display. The exhibit throws a lot of good science at visitors, but falters in explaining why it matters. The point of all this is not to nit-pick the design choices at AMNH, but to reiterate that phylogenetically-arranged fossil exhibits are really hard to pull off. This is not the most intuitive way to introduce the history of life, or even the process of evolution. With so much background to cover, perhaps a more structured and linear layout would be better. In fact, a lot of my issues with the AMNH fossil exhibits seem to stem from a disconnect between the phylogenetic interpretive content and the wide-open aesthetics. Open exhibits can be great, but in this case it hinders the learning opportunities for self-guided groups of visitors. It’s difficult to imagine a typical visitor, arriving with their family or another mixed-age group, having the patience to make sense of it all. Regrettably, such visitors default to the dinosaur pageantry level of understanding, making all the work invested in creating a meaningful exhibit space for naught.


Norell, M, Gaffney, E, and Dingus, L. (1995). Discovering Dinosaurs in the American Museum of Natural History. New York, NY: Alfred A. Knopf, Inc.

Torrens, E. and Barahona, A. (2012). Why are Some Evolutionary Trees in Natural History Museums Prone to Being Misinterpreted? Evolution: Education and Outreach 1-25.


Filed under AMNH, dinosaurs, exhibits, fish, FMNH, fossil mounts, mammals, museums, opinion, reptiles, reviews, systematics