Tag Archives: fossil mounts

Was the Hawkins Hadrosaurus real?

Photo from Weishampel and Young 1996.

Hadrosaurus at the Academy of Natural Sciences. Photo from Weishampel and Young 1996.

In the “Claosaurus” post earlier this week, I temporarily(?) lost my mind when I said that the Hadrosaurus Benjamin Waterhouse Hawkins assembled for the Academy of Natural Sciences was 100% plaster reconstruction. Thanks to John Sime, among others, for pointing out that this was incorrect. As usual, the truth is more complicated, and therefore much more interesting.

The Hadrosaurus project began when Hakwins was commissioned to create a series of life-sized prehistoric animals for display in New York City’s central park, under the direction of Joseph Leidy. The exhibition was cancelled when Hawkins’ on-site workshop was burned down by vandals, but he was able to salvage the Hadrosaurus skeleton for display at the Academy in Philadelphia. This reconstruction was based on little more than two limbs and a handful of vertebrae. It was a well-reasoned attempt – and it drew huge crowds – but it wasn’t long before new dinosaur finds rendered it obsolete. In 1901, Charles Beecher wrote that the Hadrosaurus mount had “long since ceased to have any value or interest except as a historical attempt.” No longer considered informative, the original Hadrosaurus was probably dismantled around the start of the 20th century. At least three plaster copies were distributed to other museums, but these were also discarded long ago.

There is no question that Hawkins’ reconstruction doesn’t reflect our present understanding of this animal, so in that sense it isn’t “real.” Still, it is of historic interest whether Hawkins used the handful of original Hadrosaurus fossils in the mount itself, or whether the entire display was fabricated. There is precedent for both posibilities: John Peale mounted an original mastodon skeleton in 1802, but the Smithsonian’s first attempts at Basilosaurus and Triceratops (1895 and 1900 respectively) included no real fossils. This question was actually up for discussion as early as 1926. Responding to an inquiry from Peabody Museum paleontologist Richard Lull, Academy of Natural Sciences curator Witmer Stone wrote that the Hadrosaurus mount was a complete reproduction. When Lull followed up with William Matthew of the American Museum of Natural History, however, Matthew recalled that “some or all of the original bones were used.”

The two letters reproduced below are in the collection of the Department of Vertebrate Paleontology Archives at the Peabody Museum of Natural History, and are shared with permission.

courtesy

Letter from Witmer Stone to Richard Lull, January 26, 1925. Courtesy of the Dept. of Vertebrate Paleontology Archives, Yale Peabody Museum of Natural History.

Courtesy

Letter from William Matthew to Richard Lull, January 30, 1925. Courtesy of the Dept. of Vertebrate Paleontology Archives, Yale Peabody Museum of Natural History.

A look at the original Hadrosaurus fossils, now cataloged as ANSP 10005, suggests that Matthew was correct. At least a couple of the bones appear to bear drill holes, a tell-tale sign that they were once fastened to an armature. Likewise, in a photograph of the mount in Hawkins workshop, the elements that were actually recovered – the left leg*, part of the pelvis, and a scattering of vertebrae – appear to be darker in color. This suggests that these are the real bones, and the rest of the skeleton is plaster…unless Hawkins painted plaster casts to demonstrate which elements had been found.

*Note that the image below has been flipped horizontally for some reason. In the original, the left side of the skeleton is facing the camera.

Hawkin's studio

Hadrosaurus in Hawkins’ studio. Image from Carpenter et al. 1994.

The answer to this little conundrum can be found in the official guidebook to the Academy of Natural Sciences, published in 1879. Apparently there were two versions of Hadrosaurus on display. The original 1868 mount did include the original fossils, but when the museum moved to a larger facility in 1876 (in part because of the spike in visitation caused by the Hadrosaurus exhibit) the mount was remade. The bones were not faring well in open air and were rapidly deteriorating, so they were retired to the collections and replaced with casts. Anyone who saw the Hadrosaurus before 1876 saw the fossils incorporated into the mount, and anyone who visited later saw a complete facsimile. Still, I’m pretty sure William Matthew was remembering incorrectly. He was born in 1871, so unless he was carefully observing the composition of the mount at age 5, he shouldn’t have seen the original version!

References

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.

Carpenter, K., Madsen, J.H. and Lewis, L. 1994. Mounting of Fossil Vertebrate Skeletons. Vertebrate Paleontological Techniques, Vol. 1. Cambridge, UK: Cambridge University Press.

Prieto-Márquez, A., Weishampel D.B., and Horner J.R. 2006. The dinosaur Hadrosaurus foulkii, from the Campanian of the East Coast of North America, with a re-evaluation of the genus. Acta Palaeontologica Polonica. Vol. 51, pp. 77-98.
Ruschenberger, W.S.W. and Tryon, G.W. 1879. Guide to the Museum of the Academy of Natural Sciences of Philadelphia. Philadelphia, PA: Academy of Natural Sciences.
Weishampel. D.B. and Young, L. 1996. Dinosaurs of the East Coast. Baltimore, MD: The Johns Hopkins University Press.

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

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.

woo

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.

References

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.

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

AMNH 5027 at 100

In December 1915, the American Museum of Natural History unveiled the very first mounted Tyrannosaurus rex skeleton, irrevocably cementing the image of the towering reptilian carnivore in the popular psyche. For a generation, AMNH was the only place in the world where one could see T. rex in person. Despite the tyrant king’s fame, old books emphasize the rarity of its fossils. The situation is very different today. In the last 30 years, the number of known Tyrannosaurus specimens has exploded. Once elusive, T. rex is now one of the best known meat-eating dinosaurs, and real and replica skeletons can be seen in museums around the world. The AMNH mount is no longer the only T. rex around, nor is it the biggest or most complete. It was, however, the first, and in a few weeks it will mark the 100th anniversary of its second life. Below is a partially recycled recap of this mount’s extraordinary journey.

Photo by the author.

AMNH 5027 in November 2015. Photo by the author.

The mount known as AMNH 5027 is actually a composite of material from two individuals. The first is the Tyrannosaurus rex holotype (originally AMNH 973, now CM 9380), which was discovered by Barnum Brown and Richard Lull during an AMNH expedition to Montana in 1902. The find consisted of little more than the pelvis, a single femur, one arm and shoulder, and fragmentary portions of the jaw and skull. Nevertheless, this was enough for AMNH director Henry Osborn to publish a brief description in 1905, as well as coin the species’ brilliantly evocative name. That same year, Adam Hermann prepared a plaster replica of the animal’s legs and pelvis, using Allosaurus fossils as reference when sculpting the missing lower legs and feet. This partial mount was initially displayed alongside the skeleton of a large ground bird, in order to accentuate the anatomical similarities.

Brown located a better Tyrannosaurus specimen in 1908. Apparently fearing poaching or scooping, Osborn wrote to Brown that he wished to “keep very quiet about this discovery, because I do not want to see a rush into the country where you are working.” After vanquishing many tons of horrific sandstone overburden, Brown returned to New York with what was at the time the most complete theropod specimen ever found. In addition to an “absolutely perfect” skull, the new find included most of the rib cage and spinal column, including the first half of the tail (Osborn 1916). Lowell Dingus would later describe this second specimen (the true AMNH 5027) as “a nasty old codger”, suffering from severe arthritis and possibly bone cancer. These pathologies were undoubtedly painful and probably debilitating.

Model of unrealized T. rex showdown mount from Osborn 1913.

Model of the unrealized T. rex showdown mount from Osborn 1913.

Osborn initially wanted to mount both Tyrannosaurus specimens facing off over a dead hadrosaur. He even commissioned E.S. Christman to sculpt wooden models which which to plan the scene (shown above). However, the structural limitations inherent to securing heavy fossils to a steel armature, as well as the inadequate amount of Tyrannosaurus fossils available, made such a sensational display impossible to achieve. Instead, the available fossils complemented one another remarkably well in the construction of a single mounted skeleton. Osborn noted this good fortune in 1916, but his statement that the two specimens were “exactly the same size” wasn’t quite accurate. The holotype is actually slightly larger and more robust than the 1908 specimen, and to this day the AMNH Tyrannosaurus mount has oversized legs.

The original Tyrannosaurus rex mount at the American Museum of Natural History. Photo from Dingus 1996.

The original Tyrannosaurus rex mount at AMNH. Note the original 1905 replica legs in the background. Photo from Dingus 1996.

Instead, Hermann’s team prepared a single Tyrannosaurus mount, combining the 1908 specimen with the reconstructed pelvis and legs based on the 1905 holotype. When the completed mount was unveiled in 1915, the media briefly lost their minds. In contemporary newspapers, the skeleton was called “the head of animal creation”, “the prize fighter of antiquity”, and “the absolute warlord of the earth”, among similarly hyperbolic proclamations. Even Osborn got in on the game, calling Tyrannosaurus “the most superb carnivorous mechanism among the terrestrial Vertebrata, in which raptorial destructive power and speed are combined.” With its tooth-laden jaws agape and a long, dragging lizard tail extending its length to over 40 feet, the Tyrannosaurus was akin to a mythical dragon, an impossible monster from a primordial world. This dragon, however, was real, albeit safely dead for 66 million years.

Image courtesy of the AMNH Archives.

T. rex in the Cretaceous Hall, 1960. Image courtesy of the AMNH Research Library.

The AMNH’s claim to the world’s only mounted Tyrannosaurus skeleton ended in 1941, when the holotype was sold to the Carnegie Museum of Natural History. The Pittsburgh museum’s hunch-backed reconstruction of the tyrant king was on display within a year. Although no longer the only T. rex on display, the AMNH mount certainly remained the most viewed as the 20th century progressed. It became an immutable symbol for the institution, visited again and again by generations of museum goers. Its likeness was even used as the iconic cover art of Michael Crichton’s Jurassic Park.

By the 1980s, however, a new wave of dinosaur research had conclusively demonstrated that these animals had been active and socially sophisticated. The AMNH fossil galleries had not been updated since the 1960s, and the upright, tail-dragging T. rex in particular was painfully outdated. AMNH had once been the center of American paleontology, but now its displays were lagging far behind newer museums.

finished mount, room under construction

Restoration of AMNH 5027 was completed nearly three years before the hall reopened. Photo from Dingus 1996.

Between 1987 and 1995, Lowell Dingus coordinated a comprehensive, $44 million renovation of the AMNH fossil exhibits. As part of the project, chief preparator Jeanne Kelly led the restoration and remounting of the most iconic specimens, Apatosaurus and Tyrannosaurus. Of the two mounts, the Tyrannosaurus presented the bigger challenge. The fossils were especially fragile, and some elements, specifically the cervical vertebrae, had never been completely freed from the sandstone matrix. It took six people working for two months just to strip away the layers of shellac applied by the original preparators. All told, the team spent a year and a half dismantling, conserving, and rebuilding the T. rex.

Phil Fraley’s exhibit company constructed the new armature, which gave the tyrant king a more accurate horizontal posture. While the original mount was supported by obtrusive rods extending from the floor, the new version is actually suspended from the ceiling by a pair of barely-visible steel cables. Playing with Christman’s original wooden models, curators Gene Gaffney and Mark Norrell settled on a fairly conservative stalking pose, imbuing the mount with a level of dignity befitting this historic specimen. The restored AMNH 5027 was completed in 1992, but would not be unveiled to the public until the rest of the gallery was finished in 1995. Since that time, tens of millions of visitors have flocked to see this new interpretation of Tyrannosaurus. This is the skeleton that showed the world that dragons are real, and it is still holding court today.

References

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

Glut, D.F. 2008. Tyrannosaurus rex: A Century of Celebrity. Tyrannosaurus rex, The Tyrant King. Larson, Peter and Carpenter, Kenneth, eds. Bloomington, IN: Indiana University Press.

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.

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

Osborn, H.F. 1906. Tyrannosaurus, Upper Cretaceous Carnivorous Dinosaur: Second Communication. Bulletin of the American Museum of Natural History vol. 22, pp. 281-296.

Osborn, H.F. 1913. Tyrannosaurus, Restoration and Model of the Skeleton. Bulletin of the American Museum of Natural History vol 32, pp. 9-12.

Osborn, H.F. 1916. Skeletal Adaptations of Ornitholestes, Struthiomimus, and TyrannosaurusBulletin of the American Museum of Natural History vol 35, pp. 733-771.

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Filed under AMNH, dinosaurs, fossil mounts, history of science, museums, theropods

The Nation’s T. rex Revealed

The Nation's T. rex was temporarily assembled in the RCI workshop for inspection by Smithsonian staff. Source

The Nation’s T. rex was temporarily assembled in the RCI workshop for inspection by Smithsonian staff. Source

Yesterday, a press embargo lifted and the world got it’s first look at the pose the Nation’s T. rex will assume in the new fossil hall at the National Museum of Natural History. I don’t have much to add to the solid coverage at The Washington Post, NPR, and Smithsonian Magazine except holy crap, that’s awesome.

The photo above (by Nikki Kahn of The Washington Post) was taken when Smithsonian staff visited the Research Casting International workshop to inspect the mount’s progress. Located outside of Toronto, RCI is the industry leader in the art of creating mounted fossil skeletons, and their work is on display in museums all over the world. The Nation’s T. rex is one of 52 mounts the company will create for NMNH over the next three years.

Dr. Carrano gestures toward the awesomeness behind him.

Dr. Carrano gestures toward the awesomeness behind him. Source

The Nation’s T. rex (also known as Wankel Rex) is new to NMNH, but it is not a new specimen. It was discovered by Montana rancher Kathy Wankel in 1988 on land owned by the Army Corps of Engineers. The skeleton, which was for a time the most complete Tyrannosaurus known, was held in trust at the Museum of the Rockies until last April, when the Corps loaned the specimen to the Smithsonian for the next 50 years. This is the first time the original fossils have been displayed in a standing mount, but RCI has been producing casts of the specimen for years. Examples can be seen at the Great North Museum, the Royal Ontario Museum, the Perot Museum of Nature and Science, and even the Google Campus.

The Smithsonian team inspecting every inch of the 2,000 pound mount included Curator of Dinosauria Matt Carrano, Exhibit Project Manager Siobhan Starrs, and Preparator Steve Jabo. The violent scene, with the Tyrannosaurus preparing to decapitate its Triceratops prey, was first suggested by Carrano over two years ago. The inspiration came from research by Denver Fowler and colleagues, which proposed that Tyrannosaurus regularly dismembered Triceratops by pulling the head off by the frill. The dynamic pose sets the Nation’s T. rex apart from the more “regal” stances other museums have chosen for their Tyrannosaurus mounts, and also reminds visitors that this animal was a living, acting being within its environment.

A 3-D printed model of the skeleton was used to plan the pose. Source

The exhibit team used a 3-D printed model of the skeleton to plan the pose. Source

The tyrant king’s prey is none other than a cast of Hatcher, NMNH’s resident Triceratops. This composite skeleton was the first mounted Triceratops ever exhibited, and it has been on display in one form or another since 1905. An updated reproduction of Hatcher can be seen right now in The Last American Dinosaurs, but apparently this will be its last hurrah. As Carrano put it, “Hatcher’s done its duty.” Even relegated to the role of food, however, Hatcher is still an impressive beast. The skeleton is nearly as long as the Nation’s T. rex, and noticeably bigger than the Triceratops mounts at other major U.S. museums.

Hatcher Photo by the author.

Poor Hatcher knows nothing of his imminent demise at the claws of a 38-foot murderbird. Photo by the author.

The NMNH team had a few notes for RCI, both for the sake of accuracy and the sake of the exhibit. Carrano requested that the fibula be rotated slightly, while Starrs emphasized that the tail should be at least 10 feet off the ground, to prevent over-enthusiastic visitors from grabbing at it. The workshop visit was also an opportunity to explore how the mount would look among the other denizens of the National Fossil Hall. Hatcher and the Nation’s T. rex will be sharing space on the Creataceous platform with Edmontosaurus, Thescelosaurus, and the crocodile relative Champsosaurus, among others. Working out dynamic poses that also keep key lines of sight open is no easy task, and the gallery space needs to be planned down to the inch.

As is now industry standard, RCI’s armature is made up of intricate steel cradles that are custom fitted to hold each of the 150 real fossils in place. Unlike many historic mounts, no holes have been drilled in the bones and none of the delicate fossils are supporting the structure’s weight. Most bones can be removed individually, and with the right equipment, the entire mount can be assembled in just a few hours. As such, we can rest assured that this display will not only be incredibly cool, but the authentic 66 million-year-old fossils will be as safe as they could possibly be while on view for 7 million visitors per year.

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Filed under dinosaurs, exhibits, fossil mounts, marginocephalians, museums, NMNH, theropods

Denver’s Fighting Dinosaurs

Allosaurus and Stegosaurus mount

Allosaurus and Stegosaurus mounts at the Denver Museum of Nature and Science. Source

Just a quick post today to keep the blog moving. The Allosaurus and Stegosaurus skeletons at the Denver Museum of Nature and Science are among my all-time favorite fossil mounts. While there is no shortage of fighting dinosaur displays today, these mounts were something of a novelty when they were unveiled in 1995 as the centerpieces of the trendsetting “Prehistoric Journey” exhibition. A far cry from the stiff, macabre trophies that had dominated paleontology exhibits since the beginning of the 20th century, the Allosaurus and Stegosaurus plainly represent swift and active animals. Unlike many similar scenes, however, the action here is tempered with careful attention to anatomical detail: no limbs are hyperextended, and no bones are out of place.

The Stegosaurus

A postcard showing STegosaurus in the 50s

This postcard shows the original Stegosaurus mount around 1950.

High school teacher Frank Kessler discovered the Stegosaurus (DMNH 1483) in 1937 while leading a nature hike north of Cañon City. While the Garden Park region had been known for its Jurassic dinosaur fossils since the days of O.C. Marsh and E.D. Cope, Kessler’s find was in a previously unexplored area. Kessler contacted the Denver Museum of Natural History (now the DMNS), and Robert Landberg was dispatched to lead a thorough excavation. Landberg eventually recovered a 70% intact Stegosaurus, in addition to a multitude of turtles, crocodiles, and isolated dinosaur bones.

Back in Denver, Phillip Reinheimer assembled the Stegosaurus fossils into a standing mount. A former steelworker from Pittsburgh, Reinheimer was initially hired by the museum to maintain the furnaces, but eventually proved to be an uncommonly talented fossil preparator. Described by Johnson and Stucky as “a master craftsman,” Reinheimer remains something of a legend among preparators to this day. Reinheimer completed the Stegosaurus mount in 1938, and it remained a focal point of the museum’s fossil exhibits for decades afterward. In 1982, this specific specimen was named the state fossil of Colorado.

The Allosaurus

A close up of Allosaurus

Another look at Allosaurus and Stegosaurus. Source

In 1979, 12 year-old India Wood discovered and identified an Allosaurus skeleton on a friend’s ranch in Moffat County, Colorado. She excavated the find herself over a period of three years, until her mother encouraged her to reach out to the DMNS. After seeing the fossils Wood had been collecting in her bedroom, paleontology curator K. Don Lindsay agreed to excavate the rest of the skeleton. India was hired as a field assistant alongside Lindsay’s son Jim.

The project took two more summers to complete, and Wood remained an active participant. Although many at the museum remember being impressed by her knowledge and talent, Wood ultimately did not pursue paleontology as a career—she instead went on to earn an MBA from MIT and founded a business consulting firm. Meanwhile, Wood’s Allosaurus (DMNH 2149) remained in storage for more than a decade—until it was selected to feature in an ambitious new exhibit.

Prehistoric Journey

From left to right

From left to right: Wood’s Allosaurus, Karen Alf, Bryan Small, Jon Christians, Jerry Harris, Jennifer Moerman, Ken Carpenter, and Kessler’s Stegosaurus. Image from Johnson and Stucky 2013.

The DMNS had been a powerhouse of paleontology research in the early and mid 20th century, but by the 1980s its reputation had slipped away. That changed in 1989 when Richard Stucky came on board as the new Curator of Vertebrate Paleontology. Stucky brought order to the museum’s historic collections, and laid out plans for a comprehensive new exhibit entitled “Prehistoric Journey.” He also hired a new pool of talent to make the project happen, including paleontologist and preparator Ken Carpenter. As Chief Preparator, Carpenter was tasked with moving, restoring, and in some cases remaking the classic Reinheimer mounts, including the Kessler Stegosaurus. The DMNS crew also ventured into the field to collect new material for Prehistoric Journey. Among the most impressive finds was a new Stegosaurus (DMNH 2818), discovered by Bryan Small at Garden Park only a few hundred yards from where the Kessler specimen was unearthed. This articulated specimen clarified for the first time the position of the animal’s plates and spikes, and also confirmed that Stegosaurus had throat armor made up of tiny hexagonal ossicles. All of this informed the remounting of the Kessler Stegosaurus.

Carpenter’s take on this classic specimen paired it with India Wood’s Allosaurus, right in the middle of the Prehistoric Journey dinosaur gallery. The Stegosaurus is shown defending two (largely reconstructed) juveniles from the attacking theropod, while five or six Othnielia (casts) flee the scene. Twenty years after its 1995 debut, this scene is still among the most impressive fossil mounts around because of the seemingly effortless way it captures action and behavior. Carpenter and his colleagues did not only restore the shape of these animals but breathed life into them. The viewer cannot help but imagine the events that preceded this encounter, as well as the eventual outcome. The suspended bones are like brush strokes in an impressionist painting, swooping through the space and imbuing it with energy and motion. The fact that these are mostly original fossils rather than lightweight casts makes the display all the more impressive. I’ve said it many times before, but it bears repeating that fossil mounts are fascinating, challenging objects in that they are both authentic specimens and interpretive creations. In many cases these conflicting identities are jarring. However, with the right amounts of artistry, aptitude, and solid science, a fossil mount can transcend this juxtaposition and serve each identity equally well. Not an easy feat, but the DMNS Stegosaurus and Allosaurus are a defining example of the craft.

Update 2/4/2021: Details of this post were corrected at the request of India Wood.

References

Carpenter, K. (1998). Armor of Stegosaurus stenops and the Taphonomic History of a New Specimen from Garden Park, Colorado. Modern Geology Vol. 22: pp. 127-144.

Johnson, K.R. and Stucky, R.K. (1995). Prehistoric Journey: A History of Life on Earth. Golden, CO: Fulcrum Publishing.

Johnson, K.R. and Stucky, R.K. (2013). Paleontology: Discovering the Ancient History of the American West. Denver Museum of Nature and Science Annals No. 4: pp. 231-282..

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Filed under dinosaurs, DMNS, fossil mounts, museums, theropods, thyreophorans

The Pan-American Expo Triceratops Lives On UPDATE: Or does it?

Triceratops at the Natural History Museum, London.

Triceratops at the Natural History Museum, London. Source

Don’t you hate it when you miss something glaringly obvious? I’ve never seen the Triceratops skeleton at London’s Natural History Museum in person, but I’ve seen enough pictures to know that it’s a little weird. Inaccuracies like the columnar feet, dragging tail, and vertical forelimbs can be attributed the display’s age, but the head doesn’t really look like any other Triceratops skull that’s ever been found. I had assumed that the funky frill and extremely long nasal horn were sculpted flourishes, but it turns out that no part of this Triceratops is real. It’s not a heavily-reconstructed original skeleton or even a cast – it’s a papier mâché model. And not just any model, but one that I’ve already written about in a different context.

Pan American exhibition

The Lucas Triceratops model at the 1901 Pan-American Exhibition. Source

Frederic Lucas, an Assistant Curator at the United States National Museum, created this Triceratops in 1900 for the Smithsonian display at the Pan-American Exhibition in Buffalo, New York. A mix of corporate and government displays based around the themes of peace, prosperity, and technology, the Pan-American Exhibition lasted from May to November 1901 (it was cut short when President William McKinley was shot on the fairgrounds). The Smithsonian’s 7,500 square foot exhibit took nearly a year to prepare, and showcased specimens from all departments of the nascent institution. Indeed, the Smithsonian’s participation in this and other fairs around the turn of the century is significant because these attractions were the basis for the some of the first exhibits at the USNM. Displays initially created for fairs often found a home in the museum’s permanent galleries, and the fair exhibitions were generally used as a template for the first generation of Smithsonian exhibits.

The Triceratops model was meant to represent the glut of fossils from the western United States that the Smithsonian had recently acquired from O.C. Marsh. Perhaps because most of those specimens were still unpacked and unprepared (the USNM didn’t hire a dedicated fossil preparator until 1903), Lucas sculpted the skeleton freehand based on one of Marsh’s published illustrations. It’s noteworthy that Lucas was not a paleontologist – he was brought on board at the age of 21 with no formal training because of his talent for constructing taxidermy displays. At any rate, Lucas followed Marsh’s reconstruction – at the time the only Triceratops reconstruction available – religiously when constructing his full-sized model.

St. Louis Expo

The Lucas Triceratops at the Louisiana Purchase Exposition in 1904. Source

After the Pan-American Exhibition, Lucas’s Triceratops made a second appearance at the 1904 Louisiana Purchase Exposition in St. Louis, Missouri. It was rendered obsolete shortly thereafter when Charles Gilmore assembled the world’s first real Triceratops skeleton at the USNM. As I’ve covered before, the act of physically manipulating the Triceratops fossils into a standing mount showed Gilmore that Marsh’s straight-legged reconstruction was a physical impossibility.

My understanding was that the Lucas model was lost or destroyed shortly after Gilmore’s real Triceratops went on display in 1905. I should have been more skeptical, however, because exhibits like this are almost never wasted. For example, Gilmore reported in 1943 that the Hadrosaurus cast displayed at the USNM before his arrival had been discarded due to wear and tear, but the mount had actually been given to the Field Museum in the 1890s. A couple months ago, I found out that Albert Koch’s chimeric mastodon (what he called “Missourium”) was purchased by Richard Owen on behalf of the British Museum and remounted. And just this year, the Smithsonian’s 112 year-old Stegosaurus model began a new life at the Museum of the Earth in Ithaca, New York.

tweet

Hey, that looks familiar! Source

The above tweet from the London Natural History Museum finally clued me in that the Lucas Triceratops had been hiding in plain sight for more than a century. The NHM (then the British Museum) received their Triceratops from the Smithsonian in 1907 (confirmed in the July 1907 issue of The Museums Journal), just when the Smithsonian had an extra Triceratops on hand. The London model is plainly not a cast of Gilmore’s 1905 mount, but it does resemble the Lucas model in most every detail, from the way the legs are posed to the exaggerated horns and frill. The only clear difference I can see is in the position of the head, which is much more elevated in the photos from the Buffalo and St. Louis expositions. However, I imagine the model would have been partially disassembled for transport. Perhaps when it was rebuilt in London the head ended up lower, whether by accident or design.

Unless there’s reason to think there were two copies of the Lucas Triceratops, I’d say the most parsimonious conclusion is that the London Triceratops is the very same model that was first displayed at the Pan-American Exhibition in 1901. Much like it’s long-time companion Dippy the Diplodocus, this Triceratops model is a century-old historic icon, one that has introduced generations upon generations of visitors to the enormity of deep time and the wonders of our prehistoric past. Inaccurate sculpture or not, it’s definitely something to preserve and to celebrate.

UPDATE: Shortly after I finished this post, @NHM_London responded to my inquiry with the following:

Hmm

Did I speak too soon? Source

I’m dubious that the NHM Triceratops is a copy of Gilmore’s 1905 version, but hey, it *is* their museum. I’ll leave this post up for now and follow up when I find out more. I love a good museum mystery!

References

Gilmore C.W. (1905).The Mounted Skeleton of Triceratops prorsus. Proceedings of the U.S. National Museum 29:1426:433-435.

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.

Howarth, E., Rowley, F.R., Ruskin Butterfield, W., and Madeley, C. (1908). The Museums Journal, Volume 7. Museums Association.

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Filed under dinosaurs, fossil mounts, history of science, marginocephalians, museums, NHM, NMNH

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

gorgo

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

albertosaurus

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?

References

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. http://nmnh.typepad.com/smithsonian_fossils/2015/03/gorgosaurus-and-moropus.html

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.

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

Extinct Monsters: The Marsh Dinosaurs, Part III

allosaurus

A close-up of Allosaurus. Photo by the author.

Click here to start the NMNH series from the beginning.

Some time ago, I wrote about the O.C. Marsh dinosaurs at the National Museum of Natural History. These are the mounted skeletons made from the enormous collection of fossils Marsh accumulated while working for the United States Geological Survey – if you’d like, you can catch up with Part 1 (on Edmontosaurus and Triceratops) and Part 2 (on Camptosaurus, Ceratosaurus, and Stegosaurus). Looking back, I noticed that I never actually finished, so here are the two Marsh dinosaurs with as-yet untold stories.

The Thescelosaurus

The name Thescelosaurus neglectus means “neglected wonderful lizard”, because Smithsonian paleontologist Charles Gilmore found the original specimen at the bottom of a crate, more than 10 years after it arrived at NMNH. Still buried its its field jacket, this skeleton had been long overlooked by both Marsh and the museum staff. Nevertheless, Gilmore found that it was remarkably complete and that it represented a taxon new to science.

Gilmore's illustration

An illustration of the Thescelosaurus holotype prior to reconstruction. Source

Thescelosaurus at USNM.

Thescelosaurus as displayed after 1981. Photo by Chip Clark.

The specimen that would become the Thescelosaurus holotype (USNM 7757) was excavated by John Bell Hatcher and William Utterback in July of 1891, while they were collecting for Marsh in Niobrara County, Wyoming. 20 years later, Gilmore discovered that the skeleton was articulated and intact, save for the head, neck, and parts of the shoulder. He even found small patches of preserved skin on the tail and legs. According to Gilmore, the animal had been buried rapidly after death, since it showed no signs of dismemberment by scavengers.

After describing the fossils, Gilmore mounted the Thesclosaurus in relief on its left side. Other than the reconstructed skull (modeled after Hypsilophodon), the specimen was displayed almost exactly as it was found. This was important to Gilmore, because as he wrote in his published description, “I am…of the opinion that specimens so exhibited hold the attention of the average museum visitor far longer and arouse a keener interest in the genuineness of the specimen than does a skeleton that has been freed from the rock and mounted in an upright, lifelike posture.” Today at least, I suspect that the opposite is true –  visitors are generally more impressed by dynamic standing mounts than by reliefs that preserve death poses. Still, it’s fascinating to gain a small amount of insight into the motivations of a pioneering mount-maker.

Although it was first displayed in the Hall of Extinct Monsters, the Thescelosaurus was most prominently exhibited in the 1963 version of the NMNH fossil halls. Here, it joined the Edmontosaurus, Gorgosaurus, and partial Corythosaurus relief mounts along the south wall. In life, these animals were vastly removed from one another in time and space, but displayed together they almost appeared to be parts of a single quarry face. The Thescelosaurus moved to the north wall in 1981, unfortunately placed rather high and out of most visitors’ line of sight.

thescrci

Thescelosaurus cast in the RCI workshop. Source

thescrci2

Close-up of the new Thescelosaurus skull. Source

When the new National Fossil Hall opens in 2019, USNM 7757 will be replaced with a duplicate cast. The original bones will be moved to the collections, where they can be properly studied for the first time in a century. Already, technicians at Research Casting International have freed the skeleton’s left side, which had never been fully prepared. The exhibit replica assembled by RCI is beautiful, retaining the ossified tendons and cartilage impressions of the original. Mounted in a running pose, the new cast also features an updated head, based on Clint Boyd’s recent description of Thescelosaurus cranial anatomy.

The Allosaurus

Built in 1981, the Allosaurus fragilis (USNM 4734) was the last Marsh Collection dinosaur to be mounted, although bits and pieces have been on display at NMNH since 1920. There has been considerable interest in this individual recently, in part because Kenneth Carpenter and Gregory Paul proposed in 2010 that it become the neotype for Allosaurus – more on that in a moment. Others are interested in this specimen because of its unique pathologies. In addition to several broken and healed bones, the Allosaurus has a massive puncture wound on its left scapula, which nicely matches the diameter of a Stegosaurus tail spike.

Benjamin Mudge collected this specimen in 1877 near Cañon City, Colorado. Known as the Garden Park quarry, this site also produced the Stegosaurus, Camptosaurus, and Ceratosaurus on display at NMNH. Although the Smithsonian obtained the Allosaurus with the rest of the Marsh Collection around 1900, Gilmore did not look at it (or any of the theropod material) until at least 1911. All told, USNM 4734 consists of a partial skull and jaw, a complete set of presacral and sacral vertebrae, a few ribs, a pelvis, and virtually complete arms and legs. It would have had a tail as well, but Mudge’s crew accidentally threw the articulated tail over a cliff while excavating the skeleton. Norman Boss assembled a reconstructed skull, which was displayed through the 1970s. The articulated legs and feet were exhibited in a free-standing case until the late 1950s.

Reconstructed skull

Allosaurus skull  as reconstructed by Norman Boss. Image from Gilmore 1920.

This specimen’s taxonomic history merits some discussion. The holotype Marsh selected when naming Allosaurus (YPM 1930) is notoriously poor, consisting of a single phalanx, two dorsal centra, and a tooth. Dozens of very complete skeletons attributed to Allosaurus are now known, and most specialists basically agree on what an Allosaurus is, but the lack of a usable type with which to define the taxon has been an ongoing problem.

The far more complete USNM 4734 was recovered from the same quarry as the Allosaurus holotype, during the same 1877 field season. Marsh himself actually used this specimen, rather than his designated type, to illustrate subsequent publications on Allosaurus. In 1920, Gilmore flirted with the idea of nominating USNM 4734 as a neotype for Allosaurus, but for reasons that I find difficult to follow, he decided to lump both specimens into the older name Antrodemus valens. Joseph Leidy coined Antrodemus in 1870 based on a single caudal vertebra with no geologic provenance, so this move did little to fix the underlying issue. Nevertheless, Antrodemus remained a popular synonym for Allosaurus in some circles for several decades.

allosaurusskullprep

Arnold Lewis rebuilds the Allosaurus skull in 1979. Image from Thomson 1985.

When the NMNH fossil halls were renovated in 1981, the designers noticed that the exhibit badly needed a large theropod mount. Arnold Lewis was tapped to design and construct a complete mounted version of USNM 4734, with some assistance from Ken Carpenter. The tail was cast from a Brigham Young University specimen, but Lewis sculpted the belly ribs and sternum using an alligator skeleton as reference. The completed Allosaurus measures 17 feet from its grinning jaws to the tip of its tail, and a form-hugging armature makes it look particularly dynamic. This mount has been a favorite among visitors for more than 30 years, although the 2001 addition of a Stan the Tyrannosaurus cast has somewhat overshadowed the smaller theropod.

Allosaurus

The complete Allosaurus skeleton was finally exhibited in 1981. Photo by the author.

Technicians from Research Casting International took down the Allosaurus in the summer of 2014 as part of the current round of renovations. You can watch a video of the de-installation here. The skeleton will be remounted in a few years (crouching beside a nest mound), but Smithsonian researchers want to get a good look at it before that happens. In particular, curator Matt Carrano has been wondering for some time whether a partial jaw Marsh named “Labrosaurus ferox” actually belongs to this specimen. The “Labrosaurus” jaw, which has an unusual pathology caused by a bite or twisting force, came from the same quarry as USNM 4734, and appears to be the same portion of jaw that the more complete skeleton is missing. Time will tell whether Carrano’s hunch is correct. Meanwhile, Carpenter and Paul’s petition to replace the Allosaurus type with this more complete specimen from the same locality is still pending. We should expect to hear more about that soon, as well.

References

Carpenter, K., Madsen, J.H., and Lewis, L. (1994). Mounting of Fossil Vertebrate Skeletons. Vertebrate Paleontological Techniques. 285-322.

Gilmore, C. M. (1915). Osteology of Thescelosaurus, an ornithopodus dinosaur from the Lance Formation of Wyoming. Proceedings of the U.S. National Museum 49:2127:591–616.

Gilmore, C.M. (1920). Osteology of the Carnivorous Dinosauria in the United States National Museum with Special Reference to the Genera Antrodemus (Allosaurus) and CeratosaurusUnited States National Museum Bulletin 110:1-154.

Lee, J.J. (2014). The Smithsonian Disassembles its Dinosaurs. National Geographic Online.  http://news.nationalgeographic.com/news/2014/07/140731-dinosaur-hall-smithsonian-renovation-culture-science/

Paul, G.S. and Carpenter, K. (2010). Allosaurus Marsh, 1877 (Dinosauria, Theropoda): proposed conservation of usage by designation of a neotype for its type species Allosaurus fragilis Marsh, 1877. Bulletin of Zoological Nomenclature 67:1:53-56.

Thomson, P. (1985). Auks, Rocks, and the Odd Dinosaur: Inside Stories from the Smithsonian’s Museum of Natural History. New York, NY: Thomas Y. Crowell.

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Filed under dinosaurs, exhibits, Extinct Monsters, fossil mounts, museums, NMNH, ornithopods, theropods

Permo-Triassic Synapsids at NMNH

Click here to start the NMNH series from the beginning.

In the middle decades of the 20th century, museum theory and paleontological science were undergoing complementary revolutions. Museum workers shrugged off their “cabinet of curiosity” roots and embraced visitor-centric, education-oriented exhibits. Designers began to envision the routes visitors would travel through an exhibit space, and consider how objects on display could contribute to holistic stories. Meanwhile, paleontologists like Stephen J. Gould and David Raup moved their field away from purely descriptive natural history, exploring instead how the fossil record could inform our understanding of evolution and ecology. The common thread between both transitions was a focus on connections – bringing new meaning and relevance to disparate parts by placing them in a common narrative.

Between 1953 and 1963, the Smithsonian implemented an institution-wide modernization program, transforming virtually every exhibit in the museum complex. The National Museum of Natural History began renovations to its classic fossil halls in 1959, and the new exhibits were emblematic of contemporary trends in both museum design and paleontology. The plan, as devised by exhibit designer Ann Karras, was to do away with the loose arrangement of specimens and turn the east wing into a guided narrative of the biological and geological history of Earth. Responsibility for selecting specimens and writing label copy in each of the four halls fell to a different curator. In Hall 2, which housed dinosaurs and fossil reptiles, that curator was Nicholas Hotton.

Layout of the USNM east wing, circa 1963.

Layout of the NMNH east wing as of 1963.

Hotton joined NMNH in 1959 as an Associate Curator of Paleontology. Entirely onboard with Karras’s vision and the paleobiology movement as a whole, Hotton described the old exhibits as “crowded” and “unorganized.” He thought NMNH had plenty of dinosaurs, but “mammal-like reptiles”* were sorely needed if Hall 2 was to tell the complete story of amniote evolution. Following that, Hotton’s mission over the next several years was to assemble a respectable collection of synapsid specimens for NMNH, and to incorporate them into a well-illustrated exhibit on the origins of mammals. This post highlights just a few of the specimens featured in Hotton’s version of Hall 2.

*In Hotton’s day, early mammalian relatives were usually called “mammal-like reptiles”, hence their inclusion in the fossil reptile exhibit. Today, most specialists prefer a more precise definition of reptiles that excludes synapsid (mammal-line) animals. In this post, I will be using the modern classification wherever possible. 

The Dimetrodon

Prior to 1960, the non-mammalian synapsid collections at NMNH were mostly limited to early Permian pelycosaurs. The most impressive of these was a Dimetrodon gigas collected in 1917 by independent fossil hunter Charles Sternberg. One of the best collectors of his day, Sternberg worked intermittently for E.D. Cope, O.C. Marsh, and various North American museums. In the summer of 1917, however, Sternberg was on a personal collecting trip with his son Levi. Their target was the Craddock Ranch bone bed of Baylor County, Texas, which was first explored in 1909 by a University of Chicago team. Sternberg was already quite familiar with this part of western Texas, having made some of the first thorough surveys of the Permian “red beds” in the 1880s, but the site itself was new to him. Nevertheless, Sternberg was extraordinarily successful that summer, collecting hundreds of fossils from a wide range of animals. He offered this bounty to the Smithsonian, and they purchased it from him immediately.

The Craddock Ranch fossils were particularly appealing because of their unique preservation. Buried in soft clay at the bottom of a shallow pond, the fossils could be removed from the ground with relative ease, and were largely free of encrusting matrix. Although few of the bones were articulated, many were identifiable. All told, the Sternberg collection included at least 35 skulls and partial skeletons from amphibians like Cardiocephalus, Diplocaulus, and Seymouria, plus hundreds of individual Dimetrodon bones, and a single articulated Dimetrodon specimen.

Note short tail

An early photograph of the Dimetrodon mount. Image from Gilmore 1919.

Dimetrodon first displaed on north wall

The Dimetrodon was first displayed on the north wall of the Hall of Extinct Monsters. Source

That Dimetrodon (USNM 8635) was the basis for a mount constructed by T.J. Horne. The articulated skeleton included a complete series of presacral vertebrae, the shoulder girdles, most of the forelimbs, and the left femur and tibia. The skull and jaw bones were found disarticulated, but bound together in the same mass of matrix as the skeleton. Horne added the pelvic bones and sacrum from smaller Dimetrodon specimens, and sculpted the rest of the missing material in plaster to complete the mount. Notably, his reconstructed tail was extremely short and stubby. Although the American Museum and Field Museum already had Dimetrodon mounts on display, the NMNH version stood out because of its open jaws, which Charles Gilmore said “gives the animal an appearance of angrily defying one who has suddenly blocked his path.”

Gilmore added the Dimetrodon to the Hall of Extinct Monsters in 1918. Like the other standing mounts constructed under Gilmore’s supervision, the skeleton was placed on a base textured and painted to resemble the rocks in which it was found. At this point in time, the NMNH fossil halls lacked any overarching organizational scheme, and interpretive content was minimal. Nevertheless, Gilmore displayed the Dimetrodon mount with both a small model and a 15-foot oil painting by Garnet Jex, which provided general audiences a better understanding of the animal’s life appearance.

dimetrodon

Dimetrodon in the 1963 fossil reptiles exhibit. Image courtesy of the Smithsonian Institution Archives.

Dimetrodon in 2014. Photo by the author.

Dimetrodon after the 1981 renovation. Photo by the author.

During the 1962 renovation, Hotton re-contextualized the classic Dimetrodon mount as a mammal ancestor. Unmissable orange arrows pointed to the specific anatomical traits that signify the animal’s kinship with mammals, including heterodont teeth and a single temporal fenestra. By design, visitors would pass Dimetrodon before visiting the true mammals in the adjacent hall.

The Dimetrodon skeleton itself was altered during the next renovation in 1981, when it was placed on a new, untextured base and given a longer replica tail. Contemporary staff also repainted the plaster sections to more closely resemble the original fossils – a surprising reversal of Gilmore and Horne’s original intention to make the reconstructed bones obvious to viewers.

The Thrinaxodon

Pelycosaurs like Dimetrodon represent the first major synapsid radiation, but by the middle Permian they were almost entirely replaced by therapsids. A more derived group which includes modern mammals, therapsids spread across the globe and became increasingly diverse as the Permian progressed. From weasel-sized burrowers to multi-ton herbivores, non-mammalian therapsids were among the first animal groups to conquer a wide range of terrestrial niches. Hotton wanted to tell this story in the modernized fossil exhibit, but there were hardly any non-mammalian therapsids in the NMNH collections. To correct this problem, Hotton took to the field for several months in 1960, and again in 1961. He joined James Kitching in exploring the Beafort Group rocks of South Africa, which were known to produce plentiful Permian and Triassic vertebrate fossils. Hotton returned to the museum with over 200 new specimens, the best of which were used in the renovated exhibit.

Hotton’s display of South African synapsids and amphibians. Note “Baby Doll” on the far left. Photo courtesy of the Smithsonian Institution Archives.

Thrinraxodon with Cynognathus skull

Thrinaxodon paired with Cynognathus skull. Photo by the author.

Hotton’s most prized find from South Africa was a gorgeously preserved and nearly complete Thrinaxodon liorhinus (USNM 22812). Hotton called this specimen “Baby Doll”, and while it was not prepared in time for Hall 2’s 1963 opening, it would later earn a spot of honor in the exhibit. Before that happened, though, Baby Doll was actually stolen by an over-enthusiastic volunteer. The FBI located and returned the fossil a year and a half later.

Since the 1980s, the Thrinaxodon has been displayed alongside the skull of Cynognathus crateronotus (USNM 22813), which Hotton collected on the same expedition. Both are members of the cynodont clade, which includes some of the closest relatives of modern mammals.

 The Daptocephalus

Less than a month after hall 2 reopened, Nicholas Hotton returned to South Africa. This time, he was accompanied by his spouse Ruth Hotton and their three young children. For seven months, the Hottons traveled among fossil sites on different ranches, camping most nights. They collected some 300 specimens for the Smithsonian, and Hotton’s biostratigraphic mapping of the Beaufort Group brought a measure of clarity to this region’s historically convoluted geology.

Ruth Hotton made one of the trip’s most impressive finds while prospecting in a dry riverbed with her daughter, Carol (who is now a paleobotanist at NMNH). Turning a corner, she stumbled upon a dicynodont skeleton, completely exposed and lying in the middle of the channel. One can only imagine the surprise and delight of finding an articulated fossil skeleton completely uncovered. If the Hottons had been there one season earlier or one season later, the river would have undoubtedly destroyed the fossils.

Daptocephalus on display. Photo by James Di Loreto, National Museum of Natural History.

Back at the museum, Nicholas Hotton prepared the specimen (USNM 299746) and determined it to be Daplocephalus leoniceps, one of the plethora of dicynodonts known from the Beaufort Group. Based on this classification, he reconstructed the damaged skull to resemble more complete Daplocephalus specimens, and added casts of Daplocephalus limbs.

The specimen was restored in 2019 and is now labeled Platypodosaurus. Photo by the author.

As it turns out, however, USNM 299749 is not a Daplocephalus—it is a somewhat distantly related dicynodont currently called Platypodosaurus. To varying degrees, fossil mounts are hypotheses made of bone and plaster. They are based on the best information available at the time, but sometimes they need to be corrected. The NMNH “Daplocephalus” had been mislabeled and erroneously reconstructed for many years, but the 2014 renovation of the NMNH fossil halls now presented an opportunity to deconstruct the specimen and study it up close. As of 2019, Platypodosaurus was back on display with a newly reconstructed skull and limbs.

Thanks to Christian Kammerer for kindly sharing images and insight on “Daptocephalus”!

References

Gilmore, C.W. (1919). A Mounted Skeleton of Dimetrodon gigas in the United States National Museum, with Notes on the Skeletal Anatomy. Proceedings of the United States National Museum 56:2300:525-539.

Kammerer, C. (2015). Personal communication.

Lay, M. (2013). Major Activities of the Division of Vertebrate Paleontology During the 1960s. http://paleobiology.si.edu/history/lay1960s.html

Marsh, D.E. (2014). From Extinct Monsters to Deep Time: An ethnography of fossil exhibits production at the Smithsonian’s National Museum of Natural History. http://circle.ubc.ca/handle/2429/50177

Sepkoski, D. (2012). Rereading the Fossil record: The Growth of Paleobiology as an Evolutionary Discipline. Chicago, IL: The University of Chicago Press.

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Filed under exhibits, Extinct Monsters, field work, fossil mounts, history of science, mammals, museums, NMNH

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, and 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

amnhmap_1939

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 Centrosaurus, Corythosaurus, and Styracosaurus from Alberta.

Phase V: 1956 – 1990

amnhmap_1956

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 partner, 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 most dramatic aesthetic makeover — windows were covered up to create a “black box” effect, while the dinosaur mounts were illuminated dramatically from above and below. 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 illustrations, 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 onto 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

amnhmap_1995

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 molded 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 Koskinonodon) 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.

References

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.

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