Category Archives: 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, 13 year-old India Wood discovered and identified an Allosaurus skeleton on her family’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 a box under her bed, paleontology curator K. Don Lindsay agreed to excavate the rest of the skeleton.

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.

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

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

The Carnegie Quarry Diaspora

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

Dinosaur National Monument interns collect data on the quarry wall.

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

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

The Discovery

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

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

The Mounts

CMNH

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

Apatosaurus louisae – CM 3018

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

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

Fancy fisheye photo.

AMNH Barosaurus. Source

Barosaurus lentus – AMNH 6341

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

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

ROM Barosaurus.

ROM Barosaurus. Source

Barosaurus lentus – ROM 3670

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

Allosaurus fragilis – CM 11844

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

Stegosaurus ungulatus – CM 11341

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

Carnegie Camarasaurus.

Carnegie Camarasaurus. Source

Camarasaurus lentus – CM 11338

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

NMNH Camarasaurus. Photo by the author.

NMNH Camarasaurus. Photo by the author.

Camarasaurus lentus – USNM 13786

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

DMNH Diplodocus. Source

DMNH Diplodocus. Source

Diplodocus longus – DMNH 1494

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

CMNH Camptosaurus.

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

Camptosaurus aphanoecetes – CM 11337

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

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

Modern photo by the author.

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

Dryosaurus altus – CM 3392

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

National Museum of Natural History in Washington, DC.

NMNH Diplodocus. Photo by the author.

Diplodocus sp. – USNM 10865

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

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

References

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

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

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

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

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

Real or cast? If only it were that simple!

Norman Boss Brachyceratops courtesy Smithsonian archives

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

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

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

Sculpted feet

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

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

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

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

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

How much is too much?

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

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

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

Photos by the author.

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

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

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

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

Installation art in the service of science

totes awesome

Unbridled awesome. Photo by the author.

Earlier this week, Dippy the Diplodocus gave me an opportunity to discuss mounted fossil skeletons as objects imbued with cultural and historical meaning. Today, I’d like to take that a step further and discuss them as art. Hold on tight, because it’s about to get interdisciplinary up in here.

The Barosaurus and Allosaurus encounter at the American Museum of Natural History is one of the most amazing fossil displays in the world. Within the historic Theodore Roosevelt Rotunda, an adult Barosaurus skeleton rears to a height of fifty feet to protect its offspring from a charging Allosaurus. Although all three skeletons are glass-reinforced polyester and polyurethane foam casts (by necessity – it would be unwise to mount real fossil bones in such a precarious manner), they are based directly on real specimens. The adult Barosaurus is a cast of AMNH 6341, which was excavated by Earl Douglass at Dinosaur National Monument in 1923. The Allosaurus is a cast of DMNH 1483. The young Barosaurus is the most speculative of the lot and mostly consists of sculpted bones, but it includes casts of real juvenile sauropod vertebrae.

Looking past its physical properties, this display comes with an explicit pedagogical agenda. AMNH paleontologist Mark Norrell stated that the objective was “to imagine dinosaurs as living organisms, facing challenges similar to those that confront animals today.” When the exhibit was built in 1991, it was considered important to showcase what active, hot-blooded dinosaurs might be capable of. In this case, we have a portrayal of considerable speed and agility, as well as a suggestion of parental care and group living. The mount and its associated signage also invite visitors to consider the nature of the fossil record, and what questions paleontologists can and cannot definitively answer. We don’t know whether Barosaurus would have protected or even lived with its young. We don’t know if Allosaurus would have attempted to attack an animal more than three times its size. Even the ability of Barosaurus to rear up on two legs has been the subject of some debate. While not enormously far-fetched, this is still an imaginative reconstruction – one which challenges visitors to consider the evidence behind this and other displays throughout the museum.

However, even this sort of interpretation does not fully capture the experience of observing this tableau – there is something else going on here. The dynamic poses give the dinosaurs a startling presence, and it is scarcely possible not to imagine them as living animals. Visitors must consider what it would be like to encounter an Allosaurus charging at full speed, or to stand beneath a multi-ton sauropod. Standing in the center of the room, the viewer is literally surrounded by the mounts, and necessarily becomes a participant in the drama. Even if we ignore the representational identities of the dinosaurs and think of this display as a set of abstract shapes, it is still decisively monumental. The mise-en-scène draws the viewer’s eye around the room and up the neck of the Barosaurus, toward the vaulted ceiling. The scene can thus be described as a visual and physical intervention that draws each and every visitor that enters the rotunda into a shared performance.

Fancy fisheye photo.

The visitors themselves become part of the installation by providing a human scale. Source

As impressive as the mounts are on their own, they cannot be divorced from the Theodore Roosevelt Rotunda that surrounds them. Aesthetically, the grandiose nature of the skeletons compliments the neoclassical architecture. The site-specific composition also encourages visitors to look around the room and take note of structural elements they might have missed (e.g. the ceiling). But the room itself is far from a neutral exhibition space. It is a public monument to the first President Roosevelt, who Donna Haraway calls “the patron saint for the museum.” In addition to an array of canvases depicting scenes from Roosevelt’s public life,  quotations are etched into the walls under the headings Youth, Manhood, Nature, and The State. Roosevelt’s words, literally carved in stone, speak to his appreciation of the natural world, his support for what he called “the strenuous life”, and his belief in living honorably and compassionately. Were it not for the throngs of tourists, this space could be mistaken for a shrine.

There are a few possible ways to interpret  the relationship between the dinosaurs and the hall around them. We could cast the adult Barosaurus as Roosevelt’s idealized citizen. Rather than letting the Allosaurus pick off it’s more vulnerable companion, it stands its ground, for “the highest form of success comes not to the man who desires mere easy peace, but to the man who does not shrink from danger, from hardship, or from bitter toil.” Alternatively, we could follow Haraway and consider this space a monument to hyper-masculinity and paternalistic oppression. Haraway slams the Roosevelt Rotunda (which implies a male audience at the exclusion of others) and the adjacent Hall of African Mammals (which displays artificially-assembled nuclear families, always with a male leader) as products of the wealth and privilege of the early-20th century aristocracy. But if we assume – as many visitors apparently do – that the defending Barosaurus is female, the dinosaurs might be read as a direct critique of the institution’s history. While political and sociological readings probably didn’t come up much when these mounts were being constructed, intent isn’t the whole story. This is a public space, and visitors can and will make conscious and unconscious connections between the various objects on view. Besides, this wouldn’t be the first time fossils have been entwined with presidential politics.

Different

The fossils weren’t created to be displayed in this space, but the mounts were. Photo by the author.

A museum display always involves the staging or framing of the world. It is this infusion of creative choice that moves  fossil mounts beyond the realm of science and into art. As Polliquin puts it, a specimen from nature “permits or invites experience, wheras a work of art is intentionally made for an experience.” Whether they are composed of real fossils or casts thereof, fossil mounts are purposefully constructed to exist in the museum environment. Paradoxically, they are both the objects of scrutiny and the exhibit context. This is not something to hide or be ashamed of, but to celebrate. These mounts embody aesthetic  beauty, deep history, and rich culture, and these elements are just as important as their scientific value when we consider their role in the museological landscape.

References

Haraway, D. (1985). Teddy Bear Patriarchy: Taxidermy in the Garden of Eden, New York City, 1908-1936. Social Text 11:20-64.

Kohlstedt, S.G. (2005). “Thoughts in Things” Modernity, History, and North American Museums. Isis 96:4:586-601.

Lindsay, W., Larkin, N. and Smith, N. (1996). Displaying Dinosaurs at the Natural History Museum, London. Curator 39:4:262-279.

Norrell, M.A., Dingus, L.W. and Gaffney, E.S. (1991). Barosaurus on Central Park West. Natural History 100:12:36-41.

Polliquin, R. (2012). The Breathless Zoo: Taxidermy and the Cultures of Longing. University Park, PA: Pennsylvania State University Press.

Vogel, S. (1991). Always True to the Object, in Our Fashion. Exhibiting Cultures: The Poetics and Politics of Museum Displays. Washington, DC: Smithsonian Institution Press.

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Filed under AMNH, dinosaurs, education, exhibits, fossil mounts, museums, paleoart, reptiles, sauropods, theropods

The Glorious Journey of Gorgeous George

Since 2000, Sue the Tyrannosaurus rex has been the Field Museum of Natural History’s star attraction. However, Sue is not the first dinosaur to grace the Stanley Field Hall, or even the first tyrannosaur. In March of 1956, the mounted skeleton of a Daspletosaurus (then called Gorgosaurus, more on that in a moment) poised menacingly over a prone Lambeosaurus was unveiled in the museum’s entrance hall. Assembled by preparator Orville “Gilly” Gilpin and affectionately called Gorgeous George, the Daspletosaurus remained in this position of honor for more than 30 years, before being remounted and relocated to the 2nd floor paleontology exhibit. As one of only a few new dinosaur mounts constructed in the middle decades of the 20th century, the story of Gorgeous George speaks volumes about midcentury museum paleontology.

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

The Daspletosaurus in it’s original position in the Stanley Field Hall. Photo courtesy of Field Museum Photo Archives.

The fossils in question were discovered in 1914 near the Red Deer River in Alberta, by none other than Barnum Brown. Consisting of a skull, a nearly complete set of cervical and dorsal vertebrae, a partial pelvis, and most of the rib cage, the specimen entered the American Museum of Natural History collections as AMNH 5434. It was labeled Gorgosaurus libratus, a species named and described by Lawrence Lambe that same year. Tyrannosaur remains from southern Alberta’s Dinosaur Park Formation were routinely referred to Gorgosaurus, until Dale Russell re-evaluated much of the available material in 1970.

Russell proposed two major changes to the nomenclature. First, the genus Gorgosaurus was eliminated*, considered a junior synonym of the older name Albertosaurus. Second, Russell referred several specimens formerly classified as Gorgosaurus to a new genus, Daspletosaurus. However, Gorgeous George was not among the specimens used to name Daspletosaurus – it wouldn’t be identified as such until Thomas Carr published on it in 1999. This all means that Gorgeous George has had three names over the past century: Gorgosaurus from 1914 to 1970, Albertosaurus until 1999, and Daspletosaurus after that. I will refer to this specimen as Daspletosaurus from here on out for the sake of clarity.

*Just to complicate things further, Russell’s decision to lump Gorgosaurus into Albertosaurus is no longer supported by most of today’s specialists. Gorgosaurus and Albertosaurus are different taxa, but they are still more closely related to one another than to any other known species. Keep in mind that many taxonomical discussions concerning dinosaurs come down to personal preference, rather than actual reflections of biodiversity.

Gilpin secures skull on 24 Jan 1956

Gilpin secures the Daspletosaurus skull to the armature. Source

The FMNH board of trustees purchased the partially prepared Daspletosaurus fossils from AMNH in 1955. Board member Louis Ware spearheaded the effort, which according to the March 1956 members’ bulletin was “the most important acquisition to the museum in recent years.” Notably, FMNH acquired the dinosaur explicitly to construct a display mount – there were no specific research plans for the specimen. The mid 20th century was, after all, a quiet period for dinosaur paleontology. Although these animals remained consistently popular with the public, most paleontologists of the day considered them uninteresting evolutionary dead-ends. The golden age of fossil mount construction was long over, and the Daspletosaurus was one of only a handful of new mounts built in the 1950s and 60s.

Resident preparator Orville Gilpin led the mounting process with the help of Cameron Gifford, Stanley Kuczek, and William Turnbull. Gilpin was particularly enthusiastic about the project because it was an opportunity to test his skill at building a free-standing mount, with no visible armature of any kind. This was possible because the most of the weight-bearing lower limbs would be plaster replicas. These facsimile bones could be sculpted around a steel armature, effectively hiding the support structure from view and eliminating the need for unsightly external rods. Nevertheless, this plan required a significant amount of destructive drilling on the upper half of the skeleton. Gilpin drilled holes through each of the dorsal and cervical vertebrae, then threaded each bone onto the 1.5-inch steel rod needed to support the spinal column and skull.

Unlike many theropod mounts, the Daspletosaurus was mounted with its real skull. At over 200 pounds, the massive fossil skull presented a substantial structural problem, and Gilpin consulted with engineers to determine the minimum support rod thickness needed to carry its weight. This mount was also unusual for its time in that it included a gastrallia basket (plaster, not original bone).

The Daspletosaurus skeleton included one original leg bone – the right femur. Gilpin was determined to include it in the mount, despite the need for an internal armature. His grim solution to this problem is worth quoting in full:

“The childlike urge to break something was satisfied when I came to prepare the legs of our skeleton. The right femur was bone. The only way to get a 2 inch pipe through it was to break it all to pieces. The internal bone was discarded, and the surface pieces were put back together around the pipe. This procedure may not be proper, but it seemed justified in this case” (Gilpin 1959, 165).

That’s right. Gilpin completely destroyed the Daspletosaurus femur, one of only a handful in existence, for the sake of creating a free-standing mount. Why did the femur have to be included, if doing so would involve permanently disfiguring it? Who knows. This remarkably candid story does, however, demonstrate that during the mid 20th century, dinosaur specimens were thought of as display pieces first, and irreplaceable specimens second.

December 12 1955

By December 1955, all the original fossils had been mounted, and Gilpin’s team began adding plaster elements to complete the skeleton.

From its snarling snout to the tip of its dragging tail, the completed Daspletosaurus mount was 26 feet long and 15 feet tall. Gilpin opted to pair it with a Lambeosaurus skeleton, which was recovered by the Field Museum’s own Elmer Riggs in 1922 but never exhibited. This evocative predator-prey scenario foreshadowed the more dynamic dinosaur mounts that would start to appear in the 1980s. Although there were already two dedicated fossil halls on the museum’s second floor, the new mount was considered important enough to join the classic Carl Akeley elephants in the central Stanley Field Hall. Much like the unveiling of the original Tyrannosaurus mount at AMNH in 1915 and Sue in 2000, George’s March 27th debut was a well-publicized evening event. Speakers included FMNH president Stanley Field and AMNH Curator of Fossil Reptiles Edwin Colbert.

Addendum 4/2018: Emily Graslie recently produced a video featuring Gorgeous George, including a dramatic reading of a poem former curator Eugene Richardson wrote about the mount. It is not to be missed. 

Photo by the author

The remounted Daspletosaurus in the Evolving Planet exhibit. Photo by the author.

After decades on display, the Daspletosaurus was removed from its original location around 1990 to make way for a replica Brachiosaurus skeleton. Gorgeous George reappeared in 1994, as part of the modernized “Life Over Time” exhibit on the second floor. Gilles Danis of Prehistoric Animal Structures, Inc. was contracted to revitalize the Daspletosaurus for the new exhibit, along with several other historic mounts. The new George still stands over the same dead Lambeosaurus, but a proper horizontal posture and elevated tail replaces the classic Godzilla pose. Additionally, the new mount features a replica skull. This Daspletosaurus is still on view today.

References

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

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

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

Russell, D.A. (1970). Tyrannosaurs from the Late Cretaceous of Western Canada. National Museum of Natural Sciences Publications in Paleontology. 1:1-34.

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Filed under dinosaurs, FMNH, fossil mounts, history of science, museums, reptiles, theropods