Category Archives: dinosaurs

May 18, 2014 · 3:44 pm

Extinct Monsters Updated

This early artist’s conception of the new NMNH fossil hall was on display on closing day.

Way back in 2012, I wrote a series of posts on the history of fossil displays at the National Museum of Natural History. Now that the old exhibit is closed for five years of renovation, it seemed like a good idea to go back and revise the old articles. That, and it can be very painful to read things I wrote over a year ago. Each of the seven posts, plus the launch page, have been substantially updated with new information, new images, and less abuse of the passive voice. You can check out the new articles via the Extinct Monsters link at the top of the page, or by clicking here.

Mount Making at MMFC14

This past week, I had the fantastic opportunity to be a part of the Mid-Mesozoic Field Conference. I can’t possibly offer enough praise to conference leaders ReBecca Hunt-Foster, Jim Kirkland, and John Foster for pulling off this amazingly informative journey across the Colorado plateau. Unfortunately, since we live in a world where it’s a bad idea to post images of fossil localities, and it’s downright toolish to share details about unpublished research, I won’t be posting a ton about the conference right now.

What I can share, however, are two stops we made that are especially relevant to this blog. The first is the Gaston Design workshop in Fruita, Colorado. Rob Gaston and his team specialize in casting and sculpting fossil replicas, and their mounted skeletons are on display all over North America, but especially at younger museums in the western interior. Gaston showed us how they mold, cast, and sculpt fossil replicas, a process that relies a great deal more on artistic and technical skill than fancy equipment.

This second set of photos is from the College of Eastern Utah Prehistoric Museum in Price, Utah. Ken Carpenter, the museum’s new director, has taken on the task of completely remounting the menagerie of Morrison dinosaurs in the center of the paleontology wing (some photos of the old mounts here). The original Allosaurus, Camptosaurus and Stegosaurus mounts from the late 1980s suffered from an unfortunate case of the tail-drags, and the Camarasaurus had previously been relegated to a death pose. Carpenter’s new mounts, which combine original fossils with new and old reconstructed bones, are much livelier. The stated goal of the project is to encourage visitors to imagine what it would be like to encounter these animals in life. What’s really awesome, though, is that the mounts are being built right in the exhibit, so that visitors can see the progress and the tools and techniques used to build these displays. At present, Allosaurus and Camptosaurus are finished, work on Stegosaurus is underway, and the Camarasaurus skeleton is laid out in pieces.

Sorry to post such a short tease of the awesome stuff we saw at the conference. My head is absolutely packed with information and ideas, so hopefully there will be opportunities to share more soon!

Fossil Mount FAQs

Parasaurolophus at the Field Museum of Natural History. Source

I’ve added a Fossil Mount FAQs document to the top of the page. As the name suggests, this is meant to answer some of the questions about mounted fossil skeletons that I am regularly asked during outreach programs. Right now, the document mostly covers how mounts are created and how they can be interpreted, but I plan to expand the list of questions as needed. Please leave a comment if there is something you think should be included.

Displaying the Tyrant King – Part 3

Subtlety is unnessesary when T. rex is involved.

Who needs subtlety when you have a T. rex?

Start with Displaying the Tyrant King Part 1 and Part 2.

Tyrannosaurus rex displays changed for good in the 1990s thanks to two individuals, one real and one fictional. The latter was of course the T. rex from the film Jurassic Park, brought to life with a full-sized hydraulic puppet, game-changing computer animation, and the inspired use of a baby elephant’s screeching cry for the dinosaur’s roar. The film made T. rex real – a breathing, snorting, drooling animal unlike anything audiences had ever seen. Jurassic Park was a tough act to follow, and in one way or another, every subsequent museum display of the tyrant king has had to contend with the shadow cast by the film’s iconic star.

The other dinosaur of the decade was Sue, who scarcely requires introduction. First and foremost, Sue is the most complete Tyrannosaurus ever found, with 80% of the skeleton intact. Approximately 28 years old at the time of her death, Sue is also the eldest T. rex known, as well as one of the largest. The specimen’s completeness and exquisite preservation has allowed paleontologists to ascertain an unprecedented amount of information about the lifestyle of meat-eating dinosaurs. In particular, Sue’s skeleton is riddled with fractured and arthritic bones, as well as evidence of gout and parasitic infection that together paint a dramatic picture of the rough-and-tumble world of the late Cretaceous.

From South Dakota to Chicago

Cast of Sue at Walt Disney World, Orlando. Source

It was the events of Sue’s second life, however, that made her the fossil the world knows by name. Sue was discovered in the late summer of 1990 by avocational fossil hunter Susan Hendrickson (for whom the specimen is named) on the Cheyenne River reservation in South Dakota. Peter Larson of the Black Hills Institute, a commercial outfit that specializes in excavating, preparing, and exhibiting fossils, initially intended to display the Tyrannosaurus at a new facility in Hill City, but soon became embroiled in an ugly four-way legal battle with landowner Maurice Williams, the Cheyenne council, and the United States Department of the Interior. With little precedent for ownership disputes over fossils, it took until 1995 for the District Court to award Williams the skeleton. Williams soon announced that he would put Sue on the auction block, and paleontologists initially worried that the priceless specimen would disappear into the hands of a wealthy collector, or end up in a crass display at a Las Vegas casino. Those fears were put to rest in 1997 when Chicago’s Field Museum of Natural History won Sue with financial backing from McDonald’s and Disney. Including the auctioneer’s commission, the price was an astounding $8.36 million.

FMNH and its corporate partners did not pay seven figures for Sue solely to learn about dinosaur pathology. Sue’s remarkable completeness would be a boon to scientists, but her star power was at least as important for the Museum. Sue was a blockbuster attraction that would bring visitors in the door, and her name and likeness could be marketed for additional earned income. As FMNH President John McCarter explained, “we do dinosaurs…so that we can do fish” (quoted in Fiffer 2000). Particularly in the late 1990s, with Jurassic Park still fresh in people’s minds, a Tyrannosaurus would attract visitors and generate funds, which could in turn fund less sensational but equally important research, like ichthyology and entomology.

Still, some worried that McCarter, whose background was in business, not science, was exploiting an important specimen as a marketing gimmick at the expense of the Museum’s educational mission. This echoed similar concerns voiced 80 years earlier, when the original mounted Tyrannosaurus was introduced at the American Museum of Natural History. As president of AMNH, Henry Osborn oversaw the creation of grandiose and dramatic exhibits, with the intent to draw crowds and justify private and municipal financial support. When the Museum unveiled the Tyrannosaurus mount, Osborn held a lavish publicity gala for the New York elite and members of the press. The buzz generated by Osborn’s promotion resulted in lines around the block and front page headlines, but the attention was focused on the spectacle of the dinosaur rather than the science behind it. Many academics derided this as lowest common denominator pandering, while others, like anthropologist Franz Boas, grudgingly accepted that “it is a fond delusion of many museum officers that the attitude of the public is a more serious one, but the majority do not want anything beyond entertainment.”

Original skull of Sue the T. rex, displayed on the upper mezzanine. Photo by the author.

FMNH was under similar scrutiny as museum staff revealed their plans for Sue. The role of the corporate sponsors that paid for the fossils was a particular cause for concern, and the marketing team knew it. Although the idea of T. rex-themed Happy Meals was briefly on the table, McDonald’s and Disney wisely opted to present themselves only as patrons of science. McDonald’s got its name on the new fossil preparation lab at FMNH and Disney got a mounted cast of Sue to display at Walt Disney World, but the principal benefit to the two companies was high-profile exposure in association with youth science education. The Museum retained control over the message, highlighting Sue’s importance to paleontology and only coyly admitting her role as a promotional tool. Likewise, FMNH is the sole profiteer from the litany of shirts, hats, toys, mugs, and assorted trinkets bearing the Sue name and logo that are continually sold at the Museum and around Chicago.

You May Approach Her Majesty

Once Sue arrived at FMNH, the Museum did not hold back marketing the dinosaur as a must-see attraction. A pair of Sue’s teeth went on display days after the auction, which expanded organically into the “Sue Uncrated” exhibit, where visitors could watch the plaster-wrapped bones being unpacked and inventoried. Meanwhile, McDonald’s prepared an educational packet on Sue that was distributed to 60,000 elementary schools.

The main event, of course, was the mounted skeleton, which needed to be ready by the summer of 2000. This was an alarmingly short timetable, and the FMNH team had to hit the ground running. Much of Sue’s skeleton was still buried in rock and plaster. The bones needed to be prepared and stabilized before they could be studied, and they needed to be studied before they could be mounted. In addition, two complete Sue casts had to be fabricated: one for Disney World and one for a McDonald’s-sponsored traveling exhibit. The casts were produced by Research Casting International, the Toronto-based company that recently built the mounted menagerie for “Ultimate Dinosaurs“. Phil Fraley Productions, the same exhibit company that rebuilt the American Museum and Carnegie Museum T. rex mounts, was tapped to mount Sue’s original skeleton.

The mounted skeleton of Sue in the Stanley Field Hall. Photo by the author.

Unlike every other Tyrannosaurus mount before or since, Sue can hardly be called a composite. With the exception of a missing arm, left foot, a couple ribs, and small number of other odds and ends, the mounted Sue skeleton is composed of real fossils from a single individual. FMNH public relations latched onto this fact, emphasizing in press releases that while “many museums are displaying replicas of dinosaur skeletons, the Field Museum has strengthened its commitment to authenticity. This is Sue.” Just as they did with the AMNH Tyrannosaurus, Fraley’s team built an armature with individual brackets securing each bone, allowing them to be removed with relative ease for research and conservation. No bolts were drilled into the bones and no permanent glue was applied, ensuring that the fossils incur only minimal damage for the sake of the exhibit. Despite these improvements over historic mount-making techniques, however, the Sue mount does have some inexplicable anatomical errors. The coracoids should be almost touching in the middle of the chest, but the shoulder girdles are mounted so high on the rib cage that there is a substantial space between them. Consequently, the furcula (wishbone) is also positioned incorrectly.

After a private event not unlike the one held by Osborn in 1915, Sue was revealed to the public on May 17, 2000 with the literal raising of a curtain. A week-long series of celebrations and press junkets introduced Sue to Chicago, and she has been one of the city’s biggest attractions every since. All the publicity paid off, at least in the short term: FMNH attendance soared that year from 1.6 million to 2.4 million. 14 years later, Sue the Tyrannosaurus is still known by name, and is even used as the voice of FMNH on twitter. Interestingly, Sue’s new identity as a Chicago landmark seems to have all but eclipsed the legal dispute that was her original source of fame. A recent RedEye cover story goes so far as to proclaim this South Dakotan skeleton as “pure Chicago.”

The Nation’s T. rex

This customized truck transported the Nation’s T. rex from Montana to Washington, DC.

This year, another Tyrannosaurus specimen has rocketed to Sue-like levels of notoriety. MOR 555, also known as “Wankel Rex”, is being transferred to the Smithsonian National Museum of Natural History, where it will eventually be mounted for long-term display. Now dubbed “the Nation’s T. rex“, the promotion of this specimen has mirrored that of Sue in many ways. Front-page media coverage, first-person tweets from the dinosaur and even an official song and dance contest herald the arrival of the fossils from their previous repository, the Museum of the Rockies in Montana. Much like the “Sue Uncrated” exhibit, the process of unpacking the unarticulated bones will soon be on view in a temporary display called “The Rex Room.” Meanwhile, the very name “Nation’s T. rex” is a provocative invented identity akin to Sue’s new status as a Chicagoan.

Nevertheless, the Nation’s T. rex does not quite live up to Sue’s mystique. This Tyrannosaurus is neither as large nor as complete as Sue, and there was no prolonged legal battle or frantic auction in its past. The 60% complete skeleton was found in 1988 by Montana rancher Kathy Wankel, on land owned by the US Army Corps of Engineers. The fossils are now on a 50 year loan from from the Corps to the Smithsonian, (presumably) a straightforward transfer between federal agencies. In addition, MOR 555 is by no means a new specimen. Several casts of the skeleton are already on display, including exhibits at the Royal Ontario Museum, the Museum of the Rockies, the Perot Museum of Nature and Science, and even the Google campus. In fact, a cast of the MOR 555 skull has been on display at NMNH for years.

NMNH Director Kirk Johnson, fossil hunter Kathy Wankel, her husband Bob Wankel, and Lt. Gen. Thomas Bostick preside over the arrival of the Nation’s T. rex at the Smithsonian. Source

With that in mind, the hype around the Nation’s T. rex might seem like much ado about nothing. As this series has demonstrated, the number of Tyrannosaurus skeletons on exhibit, whether original fossils or casts, has exploded in recent years. A quarter century ago, New York and Pittsburgh were the only places where the world’s most famous dinosaur could be seen in person. Today, there may well be over a hundred Tyrannosaurus mounts worldwide, most of which are identical casts of a handful of specimens. Acquiring and displaying a T. rex is neither risky nor ambitious for a natural history museum. No audience research or focus groups are needed to know that the tyrant king will be a hit. And yet, excessive duplication of a sure thing might eventually lead to monotony and over-saturation.

So far, such fears appear to be unfounded. A specimen like Sue or the Nation’s T. rex is ideal for museums because it is at once scientifically informative and irresistibly captivating. Museums do not need to choose between education and entertainment because a Tyrannosaurus skeleton effectively does both. And even as ever more lifelike dinosaurs grace film screens, museums are still the symbolic home of T. rex. The iconic image associated with Tyrannosaurus is that of a mounted skeleton in a grand museum hall, just as it was when the dinosaur was introduced to the world nearly a century ago. The tyrant king is an ambassador to science that unfailingly excites audiences about the natural world, and museums are lucky to have it.

The Nation’s T. rex in its final pose at the Research Casting International workshop.

This week, NMNH will be celebrating all things Tyrannosaurus, starting with a live webcast of arrival of the Nation’s T. rex on Tuesday morning. Stay tuned to this blog for further coverage of the events!

References

Asma, S.T. 2001. Stuffed Animals and Pickled Heads: The Culture and Evolution of Natural History Museums. New York, NY: Oxford University Press.

Boas, F. 1907. Some Principles of Museum Administration. Science 25:650:931-933.

Counts, C.M. 2009. Spectacular Design in Museum Exhibitions. Curator 52: 3: 273-289.

Fiffer, S. 2000. Tyrannosaurus Sue: The Extraordinary Saga of the Largest, Most Fought Over T. rex ever Found. New York, NY: W.H. Freeman and Company.

Larson, N. 2008. “One Hundred Years of Tyrannosaurus rex: The Skeletons.” Tyrannosaurus rex: The Tyrant King. Larson, Peter and Carpenter, Kenneth, eds. Bloomington, IN: Indiana University Press.

Lee, B.M. 2005. The Business of Dinosaurs: The Chicago Field Museum’s Nonprofit Enterprise. Unpublished thesis, George Washington University.

Rainger, R. 1991. An Agenda for Antiquity: Henry Fairfield Osborn and Vertebrate Paleontology at the American Museum of Natural History, 1980-1935. Tuscaloosa, AL: University of Alabama Press.

Switek, B. 2013. My Beloved Brontosaurus: On the Road with Old Bones, New Science and our Favorite Dinosaurs. New York, NY: Scientific American/Farrar, Straus and Giroux.

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

Tagged as dinosaurs, fossil mounts, history of science, museums, paleontology, science communication, Tyrannosaurus

April 6, 2014 · 5:56 pm

Displaying the Tyrant King – Part 2

Old meets new: The classic Carnegie T. rex (CM 9380) is now paired with a cast of Peck’s Rex (MOR 980). Photo by the author.

Start with Displaying the Tyrant King – Part 1.

In 1915, the American Museum of Natural History unveiled the first mounted skeleton of Tyrannosaurus rex ever constructed. The Carnegie Museum of Natural History followed suit with their Tyrannosaurus mount in 1941, and for most of the 20th century New York and Pittsburgh were the only places in the world where the tyrant king could be seen in person. Nevertheless, these displays propelled Tyrannosaurus to universal stardom, and the instantly recognizable dinosaur appeared in countless books, films, and other media for years to come.

The omnipresence of T. rex was secured in part by two additional museum displays, ironically at institutions that did not have any actual Tyrannosaurus fossils on hand. The Field Museum of Natural History commissioned Charles Knight to paint a series of prehistoric landscapes in 1928, the most recognizable of which depicts a face-off between Triceratops and a surprisingly spry Tyrannosaurus. In 1947, Rudolph Zallinger painted a considerably more bloated and lethargic T. rex as part of his Age of Reptiles mural at the Peabody Museum of Natural History. Both paintings would be endlessly replicated for decades, and would go on to define the prehistoric predator in the public imagination.

Rex Renaissance

Despite enduring public enthusiasm, scientific interest in dinosaurs declined sharply in the mid-20th century, and new discoveries were few and far between. This changed rather suddenly with the onset of the “dinosaur renaissance” in the 1970s and 80s, which brought renewed energy to the discipline in the wake of evidence that dinosaurs had been energetic and socially sophisticated animals. The next generation of paleontologists endeavored to look at fossils in new ways to understand dinosaur behavior, biomechanics, ontogeny, and ecology. Tyrannosaurus was central to the new wave of research, and has been the subject of hundreds of scientific papers since 1980. More interest brought more fossil hunters into the American west, leading to an unprecedented expansion in known Tyrannosaurus fossils. Once considered vanishingly rare, Tyrannosaurus is now known from over 50 individual specimens across a wide range of ages and sizes. Extensive research on growth rate, cellular structure, sexual dimorphism, speed, and energetics, to name but a few topics, has turned T. rex into a veritable model organism among dinosaurs.

RTMP 81.6.1, aka Black Beauty, mounted in relief at the Royal Tyrell Museum. Source

The most celebrated Tyrannosaurus find from the early years of the dinosaur renaissance came from Alberta, making it the northernmost and westernmost T. rex to date. The 30% complete “Black Beauty” specimen, so named for the black luster of the fossilized bones, was found in 1980 by a high school student and was excavated by paleontologist Phil Curie. The original Black Beauty fossils were taken on a tour of Asia before finding a permanent home at the newly established Royal Tyrell Museum in Drumheller, Alberta. In lieu of a standing mount, Black Beauty was embedded in a faux sandstone facade, mirroring the environment in which the fossils were found and the animal’s presumed death pose. This relief mount set Black Beauty apart from its AMNH and CMNH predecessors, and even today it remains one of the most visually striking Tyrannosaurus displays. Since the original specimen consisted of less than half of a skeleton, much of this display is made up of sculpted bones, including the pelvis, scapula, and most of the ribs. The mounted skull is a cast, but the real skull is displayed behind glass nearby. A complete cast of Black Beauty in a traditional free-standing mount is also on display at the Swedish Museum of Natural History in Stockholm.

The World’s Most Replicated Dinosaur

Driven by the increased public demand for dinosaurs, many museums without Tyrannosaurus fossils of their own have purchased complete casts from other institutions. In 1986, the Academy of Natural Sciences in Philadelphia opened “Discovering Dinosaurs”, the world’s first major exhibit showcasing active, endothermic dinosaurs. The centerpiece of the exhibit was a cast of the original AMNH Tyrannosaurus, posed for the first time in the horizontal posture that we now know was the animal’s habitual stance. The following year, another AMNH cast appeared in the lobby of Denver Museum of Nature and Science in a strikingly bizarre pose, with one leg kicking high in the air. The mount’s designer Robert Bakker intended to push boundaries and demonstrate what a dynamic and energetic Tyrannosaurus might be capable of, although the mount has subsequently been described as dancing, kicking a soccer ball, or peeing on a fire hydrant. Meanwhile, The Royal Tyrell Museum prepared a mount of RTMP.81.12.1 (a specimen consisting of a relatively small number of postcranial bones) that was filled in with AMNH casts, including the highly recognizable skull.

Tyrannosaurus cast at the Denver Museum of Nature and Science. Source

Since the late 1990s, however, casts of another specimen have overtaken AMNH 5027 for the title of most ubiquitous T. rex. BHI 3033, more commonly known as Stan, was excavated in South Dakota in 1992 by the Black Hills Institute, a for-profit outfit specializing in excavating, preparing, and mounting fossils. Stan is significant for being over two-thirds complete and for including the best-preserved Tyrannosaurus skull yet found. BHI has sold dozens of casts of the Stan skeleton to museums and other venues around the world. At a relatively affordable $100,000 plus shipping, even small local museums and the occasional wealthy individual can now own a Tyrannosaurus mount. With over 50 casts sold as of 2017, Stan is, by a wide margin, the most duplicated and most exhibited dinosaur in the world.

Stan the Tyrannosaurus at the National Museum of Natural History. Photo by the author.

All these new Tyrannosaurus mounts are forcing museums to get creative, whether they are displaying casts or original fossils. Predator-prey pairings are a popular display choice: for example, the Houston Museum of Natural Science T. rex is positioned alongside an armored Denversaurus, and the Los Angeles Natural History Museum matches the tyrant dinosaur with its eternal enemy, Triceratops. Meanwhile, the growing number of juvenile Tyrannosaurus specimens has allowed for family group displays. A second T. rex exhibit at LACM features an adult, subadult and baby, while the Children’s Museum of Indianapolis pairs a Stan cast with the original skeleton of Bucky, a “teenage” T. rex. The most unique Tyrannosaurus mount so far is certainly the copulating pair at the Jurassic Museum of Asturias.

Tyrannosaurus versus Denversaurus at the Houston Museum of Nature and Science. Photo by the author.

Each of these displays gives a substantially different impression of Tyrannosaurus. Depending on the mount, visitors might see T. rex as a powerful brute, a fast and agile hunter, or a nurturing parent (or a gentle lover). Each mount is accurate insofar that a real Tyrannosaurus probably adopted a similar stance at some point, but the museum’s choice of pose nevertheless influences visitors’ understanding of and attitude toward the dinosaur.

Restoring the Classics

With dozens of new Tyrannosaurus mounts springing up across the country and around the world, the original AMNH and CMNH displays began to look increasingly obsolete. Unfortunately, modernizing historic fossil mounts is an extremely complex and expensive process. The early 20th century technicians that built these displays generally intended for them to be permanent: bolts were drilled directly into the bones and gaps were sealed with plaster that can only be removed by manually chipping it away. What’s more, the cumulative effects of rusting armatures, fluctuating humidity, and vibration from passing crowds have considerably damaged historic mounts over the course of their decades on display.

AMNH 5027 was restored and remounted in 1995. Photo by the author.

Despite these challenges, AMNH and CMNH have both been able to restore and update their classic Tyrannosaurus displays. While fossil mounts used to be built in-house, often by the same people who found and described those fossils, modern mounting projects are typically outsourced to specialist companies. Phil Fraley Productions, an exhibit fabrication company based in the Pittsburgh suburbs, was responsible for both T. rex restorations. At AMNH, Jeanne Kelly spent two years disarticulating and conserving each bone before Phil Fraley’s crew took over to build the new armature. The new mount not only corrected the dinosaur’s posture, but improved visitors’ view of the fossils by removing obstructive vertical supports. Instead, most of the skeleton’s weight is now supported by steel cables hanging from the ceiling. Each bone is secured to an individual metal bracket, allowing researchers to easily remove elements for study as necessary. A new cast of the skull was also prepared, this time with open fenestrae for a more natural appearance. Rather than attempting to match the dramatic and showy T. rex mounts at other museums, the AMNH team chose a comparatively subdued stalking pose. A closed mouth and subtly raised left foot convey a quiet dignity befitting this historically significant display.

Historically, the 1941 CMNH Tyrannosaurus had never quite lived up to its New York predecessor. Although it incorporated the Tyrannosaurus type specimen, it was mostly composed of casts from the New York skeleton, and it sported an unfortunately crude replica skull. It is therefore ironic that CMNH now exhibits the more spectacular T. rex display, one which finally realizes Osborn’s ambitious plan to construct an epic confrontation between two of the giant predators. As they had with the AMNH mount, Phil Fraley’s team dismantled the original display and painstakingly removed many layers of paint, shellac, and plaster from the bones. Michael Holland contributed a new restored skull, actually a composite of several Tyrannosaurus skulls. The restored holotype T. rex now faces off with a cast of “Peck’s Rex”, a specimen recovered from Montana in 1997. Despite the difficulty of modernizing the historic specimen, the team reportedly developed a healthy respect for turn of the century mount-makers like Adam Hermann and Arthur Coggeshall, who developed the techniques for making enduring displays of fragile fossils that are still being refined today.

Continue to Displaying the Tyrant King Part 3.

References

Colbert, E.H., Gillette, D.D. and Molnar, R.N. “North American Dinosaur Hunters.” The Complete Dinosaur, Second Edition. Brett-Surman, M.K., Holtz, T.R. and Farlow, J.O., eds.Bloomington, IN: Indiana University Press.

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

Johnson, K. and Stucky, R.K. 2013. “Paleontology: Discovering the Ancient History of the American West.” Denver Museum of Nature and Science Annals, No. 4.

Larson, N. 2008. “One Hundred Years of Tyrannosaurus rex: The Skeletons.” Tyrannosaurus rex, The Tyrant King. Larson, Peter and Carpenter, Kenneth, eds. Bloomington, IN: Indiana University Press.

Naish, D. 2009. The Great Dinosaur Discoveries. Berkeley, CA: University of California Press.

Norell, M., Gaffney, E.S. and Dingus, L. 1995. Discovering Dinosaurs: Evolution, Extinction, and the Lessons of Prehistory. Berkeley, CA: University of California Press.

Psihoyos, L. 1994. Hunting Dinosaurs. New York, NY: Random House, Inc.

4 Comments

Filed under AMNH, CMNH, dinosaurs, fossil mounts, history of science, museums, NMNH, paleoart, reptiles, theropods

Tagged as dinosaurs, fossils, history of science, museums, natural history museums, paleontology, Tyrannosaurus

April 2, 2014 · 9:44 am

Displaying the Tyrant King – Part 1

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

Woodrow Wilson is in the white house. The first World War is raging in Europe, but the United States is not yet involved. The women’s suffrage movement is picking up speed. And you just heard that the skeleton of an actual dragon is on display at the American Museum of Natural History in New York. It is difficult to imagine a time before every man, woman, and child in the developed world knew the name Tyrannosaurus rex, but that world existed not even a century ago. In 1915, AMNH unveiled the very first mounted skeleton of the tyrant lizard king, immediately and irrevocably cementing the image of the towering reptilian carnivore in the popular psyche.

Today, Tyrannosaurus is a celebrity among dinosaurs, appearing in every form of media imaginable. More importantly, however, it is an icon for paleontology and an ambassador to science. The cult of T. rex began in the halls of museums, and museums remain the prehistoric carnivore’s symbolic home. The mounted skeletons in museums provide the legendary T. rex its credibility: these are the authentic remains of the giant predator that once stalked North America. And yet, most of the dozens of Tyrannosaurus skeletons on display around the world are casts, and none of them represent complete skeletons (rather, they are filled in with spare parts from other specimens and the occasional sculpted bone). These are sculptures as well as scientific specimens, works of installation art composed by artists, engineers, and scientists. Herein lies the paradox presented by all fossil mounts: they are natural specimens and constructed objects, embodying a challenging duality between the realms of empiricism and imagination.

A Tyrannosaurus mount is at once educational and spectacular. Both roles were embraced at AMNH in 1915, and these dual identities have defined T. rex displays ever since. 14 years ago, FMNH PR 2081, also known as Sue, became a star attraction for the Field Museum of Natural History and the city of Chicago at large. Later this month, another T. rex will unwittingly take on a similar role: on April 15th, MOR 555, an 80% complete Tyrannosaurus specimen discovered in Montana, will be dubbed “The Nation’s T. rex“ and entered into the Smithsonian National Museum of Natural History collection with considerable fanfare.

Skull cast of MOR 555, soon to be "The Nation's T. rex", at NMNH.

Skull cast of MOR 555, soon to be “The Nation’s T. rex“, at the National Museum of Natural History. Photo by the author.

This three part series is a look back at how the tyrant king has defined, and been defined by, the museum experience. Part 1 will cover the circumstances surrounding the creation of the iconic original Tyrannosaurus mount in New York, as well as its successor in Pittsburgh. Part 2 will explore the changing role of Tyrannosaurus in museums caused by a surge of new fossil finds and a revolution in our understanding of dinosaurs. Finally, Part 3 will conclude with a discussion of the positives and negatives of a modern world saturated in all things T. rex.

The Original Tyrant

Between 1890 and 1910, the United States’ large urban natural history museums entered into a frenzied competition to find and display the largest and most spectacular dinosaur skeletons. Although the efforts of paleontologists O.C. Marsh and E.D. Cope in the late 19^th century fleshed out the scientific understanding of Mesozoic reptiles, it was these turn-of-the-century museum displays that brought dinosaurs into the public sphere. Bankrolled by New York’s wealthy aristocrats and led by the ambitious mega-tool Henry Osborn, AMNH won the fossil race by most any measure. The New York museum completed the world’s first mounted skeleton of a sauropod dinosaur in 1905, and also left its Chicago and Pittsburgh competitors in the dust with the highest visitation rate and the most fossil mounts on display.

Osborn’s goal was to establish AMNH as the global epicenter for paleontology research and education, and in 1905 he revealed his ace in the hole: two partial skeletons of giant meat-eating dinosaurs uncovered by fossil hunter Barnum Brown. In a deceptively brief paper in the Bulletin of the American Museum of Natural History, Osborn described the fossils from Wyoming and Montana, coining the names Dynamosaurus imperiosus and Tyrannosaurus rex (a follow-up paper in 1906 reclassified “Dynamosaurus” as a second Tyrannosaurus specimen). Fully aware of what a unique prize he had in his possession, Osborn wasted no time leveraging the fossils for academic glory (and additional funding from benefactors). He placed the unarticulated Tyrannosaurus fossils on display at AMNH shortly after his initial publication, and commissioned legendary artist Charles Knight to prepare a painting of the animal’s life appearance.

In 1908, Brown collected a much more complete Tyrannosaurus specimen (AMNH 5027), with over 50% of the skeleton intact, including the first complete skull and a significant portion of the torso. With this specimen in hand, AMNH technician Adam Hermann and his team began work on a mounted Tyrannosaurus skeleton to join the Museum’s growing menagerie of mounted dinosaurs and prehistoric mammals. Inspired by the Museum’s collection of taxidermy mounts in dynamic habitat dioramas, and seeking to accentuate the spectacle of his reptilian monster, Osborn initially wanted to mount two Tyrannosaurus skeletons facing off over a dead hadrosaur. He even published a brief description complete with illustrations of the projected scene (shown below). 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.

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

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

Instead, Hermann prepared a single Tyrannosaurus mount, combining the 1908 specimen with plaster casts of leg bones from the 1905 holotype. The original skull was impractically heavy, so a cast was used in its place. Finally, missing portions of the skeleton, including the arms, feet, and most of the tail, were sculpted by hand using bones from Allosaurus as reference. During the early 20^th century, constructing fossil mounts was a relatively new art form, and while Hermann was one of the most talented and prolific mount-makers in the business, his techniques were somewhat unkind to the fossil material. Bolts were drilled directly into the fragile bones to secure them to the armature, and in some cases steel rods were tunneled right through the bones. Any fractures were sealed with plaster, and reconstructed portions were painted to be nearly indistinguishable from the original fossils. Like most of the early AMNH fossil mounts, preserving the integrity of the Tyrannosaurus bones was often secondary to aesthetic concerns like concealing the unsightly armature.

Tyrannosaurus and others in AMNH Dinosaur Hall, 1927. Photo courtesy of AMNH Research Library.

AMNH Tyrannosaurus, ca. 1940. Photo courtesy of the AMNH Research Library.

The completed Tyrannosaurus mount, a magnificent sculptural combination of bone, plaster, and steel, was unveiled in 1915 to stunned audiences. The December 3rd New York Times article was thick with hyperbole, declaring the dinosaur “the prize fighter of antiquity”, “the king of all kings in the domain of animal life,” “the absolute warlord of the earth” and “the most formidable fighting animal of which there is any record whatsoever” (and people say that today’s science journalism is sensationalist!). 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.

Today, we know that the original AMNH Tyrannosaurus mount was inaccurate in many ways. The upright, tail-dragging pose, which had been the most popular attitude for bipedal dinosaurs since Joseph Leidy’s 1868 presentation of Hadrosaurus, is now known to be incorrect. More complete Tyrannosaurus skeletons have revealed that the tail reconstructed by Osborn and Hermann was much too long. The Allosaurus-inspired sculpted feet were too robust, the legs (casted from the 1905 holotype), were too large compared to the rest of the body, and the hands had too many fingers (the mount was given proper two-fingered hands when it was moved in 1927). It would be misleading to presume that the prehistoric carnivore’s skeleton sprang from the ground exactly as it was presented, but it is equally problematic to reject it as a fake. There are many reasons to criticize Osborn’s leadership at AMNH, but he did not exhibit outright forgeries. The 1915 Tyrannosaurus mount was a solid representation of the best scientific data available at the time, presented in an evocative and compelling manner.

The AMNH Tyrannosaurus mount was no less than an icon: for paleontology, for its host museum, and for the city of New York. The mount has been a New York attraction for longer than the Empire State Building, and for almost 30 years, AMNH was the only place in the world where visitors could see a T. rex in person. In 1918, Tyrannosaurus would make its first Hollywood appearance in the short film The Ghost of Slumber Mountain. This star turn was followed by roles in 1925’s The Lost World and 1933’s King Kong, firmly establishing the tyrant king’s celebrity status. It is noteworthy that special effects artist Willis O’Brian and model maker Marcel Delgado copied the proportions and posture of the AMNH display exactly when creating the dinosaurs for each of these films. The filmmakers apparently took no artistic liberties, recreating Tyrannosaurus precisely how the nation’s top scientists had reconstructed it in the museum.

A T. rex for Pittsburgh

In 1941, AMNH ended it’s Tyrannosaurus monopoly and sold the incomplete type specimen (the partial skeleton described in Osborn’s 1905 publication) to Pittsburgh’s Carnegie Museum of Natural History. While it is sometimes reported that this transfer took place to keep the valuable fossils out of harm’s way during World War II (e.g. Larson 2008), the deal was apparently underway well before the United States became involved in the war. Having paid an astounding $100,000 ($1.7 million in today’s dollars) for the fossils, CMNH staff wasted no time in assembling a mount of their own. The Tyrannosaurus holotype only included only about 15% of the skeleton, so most of Pittsburgh mount had to be made from casts and sculpted elements. Somewhat pointlessly, the skull fragments included with the specimen were buried inside a plaster skull replica, making them inaccessible to researchers for several decades. Completed in less than a year, the CMNH Tyrannosaurus was given an upright, tail-dragging posture very much like its AMNH predecessor.

Carnegie Museum of Natural History. Photo from NPR.

CM 9380 at the Carnegie Museum of Natural History. Source

The mid-20^th century is sometimes called the “quiet phase” in vertebrate paleontology. After enjoying public fame and generous federal support during the late 1800s, paleontology as a discipline was largely marginalized when experiment-driven “hard” sciences like physics and molecular biology rose to prominence. By the 1950s and 60s, the comparably small number of researchers studying ancient life were chiefly concerned with theoretical models for quantifying trends in evolution. Although the aging dinosaur displays at American museums remained popular with the public, these animals were perceived as evolutionary dead-ends, of little interest to the majority of scientists. Between 1908 (when Brown found the iconic AMNH Tyrannosaurus skeleton) and 1980, only four largely incomplete Tyrannosaurus specimens were found, and no new mounts of this species were built.

Continue to Displaying the Tyrant King Part 2.

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. 2008. “Tyrannosaurus rex: A century of celebrity.” Tyrannosaurus rex, The Tyrant King. Larson, Peter and Carpenter, Kenneth, eds. Bloomington, IN: Indiana University Press.

Hermann, A. 1909. “Modern Laboratory Methods in Vertebrate Paleontology.” Bulletin of the American Museum of Natural History 21:283-331.

Larson, N. 2008. “One Hundred Years of Tyrannosaurus rex: The Skeletons.” Tyrannosaurus rex, The Tyrant King. Larson, Peter and Carpenter, Kenneth, eds. Bloomington, IN: Indiana University Press.

“Mining for Mammoths in the Badlands: How Tyrannosaurus Rex Was Dug Out of His 8,000,000 Year old Tomb,” The New York Times, December 3, 1905, page SM1.

Naish, D. 2009. The Great Dinosaur Discoveries. Berkeley, CA: University of California Press.

Osborn, H.F. 1906. “Tyrannosaurus, Upper Cretaceous Carnivorous Dinosaur.” Bulletin of the American Museum of Natural History 22:281-296.

Osborn, H.F. 1913. “Tyrannosaurus, Restoration and Model of the Skeleton.” Bulletin of the American Museum of Natural History 32:9-92.

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

Wesihampel, D.B. and White, Nadine M. 2003.The Dinosaur Papers: 1676-1906. Washington, DC: Smithsonian Books.

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Filed under AMNH, CMNH, dinosaurs, fossil mounts, history of science, movies, museums, NMNH, reptiles, theropods

Tagged as dinosaurs, fossil mounts, history of science, museums, natural history museums, paleontology, Tyrannosaurus

March 17, 2014 · 2:55 pm

So that Hadrosaurus skull…

In 1868, paleontologist Joseph Leidy and artist Benjamin Waterhouse Hawkins collaborated on a freestanding mounted skeleton of Hadrosaurus. This was the first time dinosaur fossils had ever been displayed in this way, and the exhibit captured the public imagination like nothing before it. I’ve already written lots about the Hadrosaurus mount (see First Full-Sized Dinosaurs and A Visit to the Academy of Natural Sciences), but it seems there is still more to say.

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

Today, I’m interested in the Hadrosaurus head, or rather, the sculpted replica that stood in for its head. As I’ve covered before, the Hadrosaurus fossils recovered near Haddonfield, New Jersey accounted for less than a third of the animal’s skeleton. With two nearly complete limbs, 28 vertebrae, a partial pelvis and scattered teeth, Hadrosaurus was the most complete dinosaur known at the time, but a great deal of it was still unknown. Specifically, Hawkins had to create a skull from scratch, and conventional wisdom (e.g. these articles) has always been that he based his reconstruction on the skull of an iguana. That makes a certain amount of sense, since Leidy interpreted the Haddonfield teeth as having belonged to an herbivore, and an iguana is a contemporary herbivorous reptile.

Hadrosaurus teeth and dentary (plus some Astrodon teeth on the lower left). From Leidy 1865.

Let’s explore that claim a little more, though. The plate above presumably represents the entirety of the Hadrosaurus cranial material Leidy and Hawkins had to work with. In addition to an assortment of isolated teeth, they had two sections of a dental battery – that is, the grinding surface made up of interlocking teeth that we now know is typical of large ornithopods. One of the battery portions came from the lower jaw (Figs. 24 and 25) and one came from the upper (Fig. 26). The sculpted Hadrosaurus skull, which Academy of Nautral Sciences Associate Curator Ted Daeschler confirms is the only surviving part of the historic mount, is pictured below. Note that Hawkins plainly incorporated the dental batteries into his reconstruction, rather than straight rows of iguana-style teeth.

Hadrosaurus replica skull at Academy of Natural Sciences. Source

So in at least one detail, the Hadrosaurus model skull is not just a scaled-up version of an iguana. The thing is, though, now that I’m really looking at it, the model doesn’t look much like an iguana skull at all beyond the basic silhouette. Look at that broadly flared jugal, the strongly curved postorbital and especially the way the premaxilla and maxilla curve downward in a beakish fashion. None of these characteristics are present on your run-of-the-mill iguana skull, but they are so extreme and precisely modeled that I would be very surprised if expert anatomists like Leidy and Hawkins simply invented them.

Labeled Iguana iguana skull by Udo Savalli.

What does this mean? There are a few options.

Hawkins and Leidy didn’t closely reference anything when creating the Hadrosaurus skull, and just made something up.
Hawkins and Leidy based the Hadrosaurus skull on some contemporary reptile other than a green iguana.
Hawkins and Leidy had more Hadrosaurus cranial fossils than we know about.

Option three is, of course, the interesting one, and is where I would appreciate if any actual hadrosaurid experts in the house would let me know if I’m talking nonsense. But don’t those peculiar non-iguana-like characters on the sculpted Hadrosaurus skull look just a bit like the actual hadrosaurid skulls that would be found in the 20th century?

Kritosaurus skull at AMNH. Photo by WikiMedia user Ryan Somma.

That downward-tilting rostrum in particular looks suspiciously similar. Is it possible that there was a more complete Hadrosaurus skull at the Haddonfield site, but it was lost or destroyed before Leidy’s publication? Maybe it was considered too fragmentary to collect and was left in the field, or maybe it fell apart in transit (J.B. Hatcher hadn’t invented field jacketing yet). Hawkins might have attempted to interpret sketches or hazy descriptions of lost material, and ended up with the model skull that survives today. I realize that this isn’t much to go on, and that it’s impossible to prove without some thorough archival research. But it is cool to think that maybe, just maybe, there was a bit more to the first American dinosaur than we known about.

References

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

Leidy, J. (1865). “Cretaceous Reptiles of the United States.” Smithsonian Contributions to Knowledge Vol. 14, Article VI.

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

Tagged as Academy, Benjamin Waterhouse Hawkins, dinosaurs, Hadrosaurus, Joseph Leidy, museums

March 14, 2014 · 4:27 pm

What’s the deal with Astrodon?

In Laurel, Maryland, a trail of banners depicting a herd of the sauropod dinosaur Astrodon johnstoni leads the way to Dinosaur Park, the site of a historically significant fossil deposit. At the Maryland Science Center in Baltimore, a life-sized Astrodon sculpture towers over the “Dinosaur Mysteries” exhibit. And since 1998, Astrodon has been the official state dinosaur of Maryland, joining other state symbols like the black-eyed susan and Baltimore oriole. In short, Astrodon is a sort of mascot for mid-Atlantic paleontology. Named in 1858 for fossils found in a Prince George’s County iron mine, the appeal of Astrodon for Marylanders is obvious: it’s a home-grown dinosaur in a region that is not widely recognized for its fossil resources, and the story of its discovery also calls attention to the state’s industrial heritage.

But what sort of animal was Astrodon, and how much do paleontologists truly know about it? Compared to many other extinct animals found around the world, the fossil record for Astrodon is and always has been fairly poor. The name Astrodon was first bestowed upon nothing more than isolated teeth, and although other fragmentary remains attributed to Astrodon have been uncovered over the past 150 years, reconstructions of the Maryland sauropod are mostly derived from the fossils of relatives found elsewhere. What’s more, the name Astrodon has a convoluted history, having been applied haphazardly to fossils found across the country and even around the world. For these reasons, some paleontologists would prefer that the name Astrodon not be used at all.

Lacking a scientific consensus on what sort of animal the Maryland sauropod was or even what it should be called, I find myself in a difficult position as an educator. How can the messy and contentious taxonomy of Astrodon be condensed into something teachable? Is simplifying or downplaying this controversy doing our audience a disservice, and to what degree?

The taxonomic history of Astrodon

The first scientifically recognized North American dinosaur fossils were found in the Mid-Atlantic region, a scant 17 years after dinosaurs were first recognized as a biological group in 1842. Joseph Leidy’s Hadrosaurus from the New Jersey coast is credited as the first American dinosaur to be described, but Astrodon was a close second. During the mid-19th century, iron mining was big business in central Maryland. Miners extracted large boulders of siderite, or iron ore, from open pit mines throughout Prince George’s County, and these miners were the first in the region to discover dinosaur bones and teeth. The siderite was being mined from clay deposits now known as the Arundel Formation, part of the larger Potomac Group that extends throughout Maryland (the Potomac Group was laid down during the Early Cretaceous period, between 125 and 113 million years ago). Members of the Maryland Academy of Sciences recognized the fossils from the Arundel clay as similar to the English fossil reptiles that Richard Owen had recently unified as Dinosauria. In 1858, academy member Christopher Johnston published a description of a set of teeth from the iron mines in the American Journal of Dental Science, which he named “Astrodon” (Joseph Leidy turned this informal name into a proper binomial, Astrodon johnstoni, in his 1865 review of North American fossil reptiles).

Today, most paleontologists consider it poor judgment to name a new taxon based only on teeth. When scientists describe a newly discovered organism, they designate a type specimen, which is used to define that taxon in perpetuity. But when the type specimen is especially fragmentary, or only consists of a small part of the organism, it poses a problem for future researchers. In the case of Astrodon, no newly discovered fossils other than teeth can be confidently referred to the same species. In 1858, however, paleontological norms were very different. All dinosaur fossils known at the time were exceedingly incomplete: scientists knew that dinosaurs were reptiles and that they were very big and not much else. Any new fossils, even teeth, represented a major addition to our understanding of the life appearance and diversity of these extinct animals. For modern paleontologists, Johnston’s published description of the Astrodon teeth is vague and uninformative, but in his day, these fossils were distinct from anything else yet known.

Astrodon teeth are on the lower left.

In December of 1887, famed paleontologist Othneil Charles Marsh sent his best fossil hunter, John Bell Hatcher, to search the area in Prince George’s County where Astrodon was discovered. Judging from Hatcher’s journal entries, he didn’t have a great time. It rained and snowed almost constantly, and on several days his team didn’t bother to show up for work. Although Hatcher managed to find numerous dinosaur, crocodile and turtle fossils, these finds did not match the quality of the fossils Hatcher had been finding in the western states, and no return trips were made. Nevertheless, Marsh saw fit to name two new dinosaur species from the material Hatcher collected: Pluerocoelus altus and Pluerocoelus nanus. Neither taxon was named for material that would be considered diagnostic if found today: P. altus was based on a tibia and fibula, while P. nanus was based on four nonadjacent vertebrae.

By this time, more complete dinosaur fossils from the American west were beginning to reveal a clearer picture of dinosaur diversity. Based on the shape and size of the fossils collected by Hatcher, Marsh determined that they belonged to sauropods, the group of long-necked herbivores that includes Diplodocus and Apatosaurus. More specifically, Marsh recognized that the Arundel sauropods were similar to “Morosaurus” (now called Camarasaurus) from Colorado. Today, the lineage of stocky, broad-nosed sauropods that includes Camarasaurus and its closest relatives are called macronarians. Unfortunately, by modern standards Marsh’s descriptions of P. altus and P. nanus are rudimentary in nature, and no distinguishing characteristics not common to all macronarian sauropods were offered.

Pleurocoelus elements. Image from NMNH Backyard Dinosaurs.

Pleurocoelus (or Astrodon?) fossils collected by Hatcher. Image from NMNH online exhibit Backyard Dinosaurs.

Contra Marsh, Hatcher suspected that there was only one sauropod in the Arundel Formation. P. altus and P. nanus were probably growth stages of one species, and the Astrodon teeth, now recognized as typical of macronarians, probably came from the same animal, as well. Since the International Code of Zoological Nomenclature decrees that the first published name given to a taxon has priority, Astrodon would take precedence over Pluerocoelus. Later, Charles Gilmore published a review of the Arundel fossils, in which he concurred with Hatcher that P. altus was a junior synonym of Astrodon, but retained P. nanus as a separate species.

Then things started getting really complicated. While paleontologists were still debating how many sauropod species existed in the Arundel clay, Marsh and others had started naming lots of new species of Pluerocoelus. Fossils found in Texas, Oklahoma and even the U.K. were all thrown into the Pluerocoelus bucket, including P. montanus, P. valdensis, P. becklesii and P. suffosus. For much of the 20th century, Pluerocoelus was a classic wastebasket taxon, into which any and all sauropod fossils from early Cretaceous strata were casually thrown. Since the Pluerocoelus type specimens designated by Marsh were insufficient to define the taxon based on morphology, the name became little more than a temporal marker. Adding to the confusion, researchers continued to disagree over whether all these new Pluerocoelus species should be sunk into the earlier genus Astrodon.

In recent years, some progress has been made toward untangling this mess of early Cretaceous sauropods. There is a general consensus that fossils not found in Maryland’s Potomac Group differ substantially from the Arundel sauropods and should never have been referred to Pluerocoelus or Astrodon. New names have been proposed for the midwestern sauropods, including Astrophocaudia and Paluxysaurus. However, removing the non-Maryland fossils from the discussion merely returns us to the original set of problems: how many sauropods are represented in the Arundel clay, what were they like in life, and what should we call them?

Creating a coherent picture of Astrodon

Unfortunately, the answers to these questions depend on who you ask. The most thorough review of Arundel sauropods from the last decade was published by Kenneth Carpenter and Virginia Tidwell in 2005. Carpenter and Tidwell reaffirmed Hatcher’s conclusion that Pluerocoelus is synonymous with Astrodon, and that as the earliest published name, Astrodon has priority. This decision is apparently based only on the fact that the fossils came from the same stratum, however, since the Astrodon holotype cannot be compared to anything besides other teeth. For this reason, Michael D’Emic proposed in 2012 that the names Astrodon and Pluerocoelus are nomen dubia and should both be dropped entirely. Ultimately, neither solution is practical for identifying the sauropod fossils that continue to be collected from the Arundel Formation. Either we blindly refer any and all sauropod fossils to Astrodon, even though we lack a usable holotype, or we have no label available at all. One solution would be to establish a new type specimen (called a neotype) for Astrodon, but this has yet to be done.

Both camarasaur and brachiosaur shaped Astrodon reconstructions are equally reasonable.

Both camarasaur and brachiosaur-shaped Astrodon reconstructions are reasonable. Artwork by Dmitry Bogdanov, via Wikipedia.

While many more sauropod fossils have been found in the Arundel clay since Hatcher’s 1887 expedition, we do not have enough material to fully elucidate what these animals looked like. Size estimates have varied enormously, from as little as 30 feet to as much as 80 feet in length. The assortment of fossil bones and teeth that have been found tell us we have a macronarian sauropod, and we can reconstruct its general shape based on more completely known relatives. However, macronarians were a fairly diverse bunch, ranging from the comparatively stocky camarasaurs to high-shouldered, elongate brachiosaurs. Carpenter and Tidwell describe the Arundel sauropod fossils, particularly the limb bones, as being fairly slender, but still more robust than those of Brachiosaurus. They do recognize, however, that nearly all known Arundel sauropod fossils come from juveniles, which may vary proportionally from adults. Because the precise affinities of Astrodon are unclear, artistic reconstructions vary substantially. The National Museum of Natural History’s Backyard Dinosaurs exhibit and website shows a camarasaur-shaped sauropod, while the life-sized sculpture at the Maryland Science Center is based on the brachiosaur Giraffatitan. At Dinosaur Park in Laurel, meanwhile, both versions are on display. More fossils, ideally cervical vertebrae or more complete adult material, are needed to clarify what the Arundel sauropod looked really like.

Teaching Astrodon

When I show people the teeth and partial bones attributed to Astrodon during public programs, I am almost always asked, “if that’s all you’ve found, how do you know what the whole animal looked like?” As demonstrated by this post, it takes 1,700 words and counting to give a proper answer, which is too much for all but the most dedicated audiences. Nevertheless, to do anything less is to skip crucial caveats and information. Scientists are choosy about the words they use, filling explanations with “probablys” and “almost certainlys”, but they do so with good reason: when one’s job is to create and communicate knowledge, there is no room for ambiguity about what is and is not known. It is therefore just a bit dishonest to say that a large sauropod called Astrodon that was related to Brachiosaurus lived in Maryland, and yet I do so every week. How can I possibly sleep at night?

I’ll admit it can be difficult, but I get by because using one proviso-free name for the Maryland sauropod seems to be informative and helpful to my audience. I only have people’s attention for so long, and I’d rather not spend that time on tangents about how Astrodon should really be called Pluerocoelus or why my use of either name is imprecise and problematic. I want visitors to walk away understanding how paleontologists assemble clues from sedimentary structures and anatomical comparisons to reconstruct ancient environments and their inhabitants. I’d like for visitors to practice making observations and drawing conclusions, and understand how paleontology is a meticulous science that can be relevant to their lives. “Paleontologists are weirdly obsessed with changing names” is not one of the most important things to know about paleontology.

Taxonomy, the science of naming and identifying living things, is unquestionably valuable. Biologists would be lost without the ability to differentiate among taxa. From my perspective, however, the public face of paleontology tends to overemphasize taxonomic debates in lieu of more informative discussions. There will always be somebody willing to argue whether Tarbosaurus bataar should be sunk into Tyrannosaurus, or to give incorrect explanations for why we lost “Brontosaurus.” In the end, though, these debates have more to do with people’s preferences than the actual biology of these animals. Astrodon may not be a diagnostic taxon in the strictest sense, but we need to call our fossils something, and taxonomic labels exist to be informative and useful. If asked, I’m always happy to provide the full story. But for the time being, Astrodon seems to be working just fine.

References

Carpenter, K. and Tidwell, V. 2005. Reassessment of the Early Cretaceous sauropod Astrodon johnstoni Leidy 1865 (Titanosauriformes). In Carpenter and Tidwell (eds.), Thunder-Lizards: The Sauropodomorph Dinosaurs. Bloomington, IA: Indiana University Press.

D’Emic M.D. 2012. Revision of the sauropod dinosaurs of the Lower Cretaceous Trinity Group, southern USA, with the description of a new genus. Journal of Systematic Paleontology, iFirst 2012, 1-20.

Gilmore, C.W. 1921. The fauna of the Arundel Formation of Maryland. Proceedings of the United States National Museum. 59: 581-594.

Kranz, P.M. Dinosaurs in Maryland. 1989. Published by Maryland Geological Survey, Department of Natural Resources, Educational Series No. 6.

Marsh, O.C. 1888. Notice of a New Genus of Sauropoda and Other New Dinosaurs from the Potomac Formation.

Please note that the usual disclaimer applies: views or opinions expressed here are mine, and do not reflect any institution with which I am affiliated.

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Filed under citizen science, Dinosaur Park, dinosaurs, field work, history of science, reviews, sauropods, systematics

Tagged as astrodon, dinosaur park, dinosaurs, education, fossils, pluerocoelus, science communication, taxonomy

March 12, 2014 · 7:25 pm

The Top Seven Dinosaur Mounts #MuseumDinos

According to Twitter, today is #MuseumDinos day, possibly because it’s the 10th anniversary of the groundbreaking DinoSphere exhibit at the Indianapolis Children’s Museum. At any rate, dinosaurs in museums is a thing I’m kind of interested in, so here’s the first ever DINOSOURS! listicle: the hastily-planned and in-no-way-definitive top seven coolest ~~dinosaur~~ extinct animal mounts from around the world.

7. Megatherium, Museo Nacional de Ciencias Naturales

The original Megatherium fossils have been remounted at the Museo Nacional de Ciencias Naturales. Image from TripAdvisor.

Megatherium at the Museo Nacional de Ciencias Naturales. Source

Let’s start with the eldest. There are quite a few ground sloth mounts in the world, but the Megatherium in Madrid has the distinction of being the first assembled skeleton of a prehistoric animal ever put on public display. It’s hard to imagine, but when Juan Bautista Bru created this mount in 1795, biological evolution was completely unknown, and naturalists were just beginning wrap their heads around the idea that organisms could become extinct. This Megatherium was a product of a very different era of human understanding about the natural world, but unlike other historic mounts like the Peale mastodon and Leidy Hadrosaurus, it has survived to the present day.

6. Stegosaurus and Allosaurus, Denver Museum of Nature and Science

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

In addition to being a respected scientist, Ken Carpenter is among the most skilled fossil mount creators working today. Among his most recognizable work is the Stegosaurus and Allosaurus face-off at the Denver Museum of Nature and Science. Featuring a remount of a historic Stegosaurus specimen and an Allosaurus discovered and mostly excavated by 12-year-old India Wood, this lively display was unveiled in 1995 as the centerpiece of the “Prehistoric Journey” exhibit. In addition to biomechanical accuracy exceeding many other modern mounts, this display by Carpenter and Bryan Small is imbued with remarkable dynamism and energy.

5. Tyrannosaurus pair, Museo Jurasico de Asturias

Tyrannosaurus at Museo Jurasico de Asturias. Source

Then again, there are a lot of fighting dinosaur mounts. I love that dinosaurs had big teeth and killed things as much as the next person, but it’s refreshing to see a mount that showcases some other aspect of these animals’ lives. That said, the Spanish Museo Jurasico de Asturias is, as far as I know, the only museum to display a pair of copulating dinosaurs. The T. rex on the bottom looks like yet another Stan cast, but I’m not sure about the one on top.

4. Diplodocus, Carnegie Museum of Natural History (and elsewhere)

The original “Dippy” the Diplodocus at the Carnegie Museum of Natural History.

Like the Madrid Megatherium, this Diplodocus is intractably situated in history. If the worldwide popularity of dinosaurs could be traced to a single specimen, it would be this one. At the turn of the 20th century, Andrew Carnegie, who funded the creation of the Carnegie Museum in Pittsburgh, demanded that his museum find and display a sauropod dinosaur. This launched the Great American Sauropod Race, a frenzied competition among the United States’ large natural history museums to assemble the biggest dinosaur for display. The American Museum in New York was first across the finish line in 1905 with their composite “Brontosaurus”, although the Diplodocus collected by the CMNH team was a more complete specimen. Not to be outdone by his New York competitors, Carnegie commissioned several casts of the skeleton, which he presented to several cities in Europe and Latin America. Diplodocus casts sprang up seemingly overnight in London, Paris and elsewhere, and the original specimen was unveiled in Pittsburgh in 1907.

3. Giraffatitan, Museum für Naturkunde

Should the Giraffatitan at Berlin's Museum fur Naturkunde be displayed in Germany? Image from Wikipedia.

The biggest fossil mount in the world. Source

The Berlin Giraffatitan is on this list for two reasons. First, it’s really big. The biggest mount in the world composed mostly of original fossils, as a matter of fact, and big things are awesome. However, this display is also a fascinating example of the cultural meaning natural specimens can take on when placed on display. The fossils themselves were removed from what is now Tanzania under the authority of a colonial government that is no longer considered legitimate or appropriate, and the mount itself was completed in 1935, a time when the hall it was displayed in was filled with swastika flags. The fossils themselves (and the current museum staff that have inherited them) obviously have nothing to do with Nazis or colonial imperialism, but the display they were incorporated into is entrenched in history that should not be ignored or forgotten.

This is actually the second iteration of this display, the bow-legged original having been remounted in 2007.That’s one of the Carnegie Diplodocus casts peeking in from the right, by the way.

2. Triceratops, National Museum of Natural History

Triceratops at the National Museum of Natural History.

Triceratops is objectively the coolest dinosaur ever, and NMNH is the home to the definitive (and first) Triceratops mount. Charles Gilmore and Norman Boss constructed this composite skeleton in 1905 from fossils collected throughout Wyoming, resulting in a mount that was inaccurate in many details; most noticeably, the skull was too small compared to the rest of the body. Nevertheless, this Triceratops was the basis for illustrations in popular books for decades to come. In 2000, Steve Jabo and others retired the original mount, conserving the fossils and replacing them in the exhibit hall with a casted duplicate. Among other improvements, the undersized head was corrected by digitally scanning the original and 3D-printing it at a different scale.

1. Barosaurus and Allosaurus, American Museum of Natural History

Allosaurus and Barosaurus mount in the Roosevelt rotunda of the American Museum of Natural History. Source: http://www.ourtravelpics.com.

Allosaurus and Barosaurus mount at the American Museum of Natural History. Source

Was there ever any question what would be in first place ? The Barosaurus encounter in the Theodore Roosevelt rotunda at AMNH is a prime contender for the world’s most spectacular fossil mount. What I like most about this exhibit is the purposeful mise-en-scene: the dinosaurs decisively fill the space, drawing the viewer’s eye not only around the room but up the neck of the 50-foot Barosaurus toward the high vaulted ceiling. Since 2010, visitors have been able to walk between as well as around the mounts, inserting their own human scale into the scene. According to AMNH paleontologist Mark Norrell, the objective of this exhibit was “to imagine dinosaurs as living organisms, facing challenges similar to those that confront animals today.” However, Norrell freely admits that the display was also meant to be a spectacle, emphasizing the “romantic history and grandeur of fossils”.

References

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

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

López Piñero , J.M. (1988). Juan Bautista Bru (1740-1799) and the Description of the Genus Megatherium. Journal of the History of Biology. 21:1:147-163.

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

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Filed under AMNH, CMNH, dinosaurs, fossil mounts, history of science, mammals, museums, NMNH, paleoart, reptiles

Tagged as dinosaurs, fossil mounts, history of science, museums, paleoart, paleontology, pictures

February 20, 2014 · 8:39 am

Extinct Monsters: Brachyceratops

Click here to start the Extinct Monsters series from the beginning.

Most of the mounted dinosaur skeletons at the National Museum of Natural History (NMNH) represent taxa that are well-known to casual paleontology enthusiasts. But nestled amongst household names like Triceratops, Stegosaurus and Diplodocus is an easily-overlooked horned dinosaur that was historically called Brachyceratops montanensis (it’s currently labeled Styracosaurus sp). Tucked away in a glass case behind the giant Triceratops, this pocket-sized ceratopsian may not be the most spectacular display in the exhibit, but it is nevertheless an important one for the Museum. Discovered in 1913 by the Smithsonian’s own Curator of Fossil Reptiles Charles Gilmore, Brachyceratops represents one of only a few dinosaur species excavated, prepared, described and exhibited entirely in-house at NMNH. It is therefore unfortunate that modern researchers have banished the name Brachyceratops to the realm of taxonomic obscurity. What’s more, the days of the Brachyceratops mount, on exhibit since 1922, are numbered: when the NMNH paleontology halls closed for renovation in April 2014, this specimen was be retired to the collections, and is not planned for inclusion when the exhibit reopens in 2019.

The Brachyceratops mount today. Photo by the author.

During his tenure at NMNH, Gilmore was an inexhaustibly productive writer, publishing at least 170 scientific articles, including numerous important descriptions and reassessments of fossils discovered by O.C. Marsh’s teams in the 19th century. However, Gilmore was much happier studying fossils in his lab than excavating new finds in the field, taking part in a scant 16 NMNH-sponsored field expeditions over the course of his career. A 1913 trip to the Cretaceous Two Medicine Formation in Northeast Montana was therefore unusual for Gilmore. He was following in the footsteps of Eugene Stebinger of the US Geological Survey, who had reported the previous year that the region was only minimally explored but clearly awash in vertebrate fossils.

On this inaugural fossil prospecting trip, Gilmore’s team located abundant remains of fish, small reptiles and dinosaurs, especially hadrosaurs and ankylosaurs. The most notable find, however, was a small bone bed (about six feet square) of ceratopsian fossils, representing at least five individuals. Gilmore described this find in a 1917 monograph, naming the dinosaur Brachyceratops montanensis. Today we know that ceratopsians were quite diverse, particularly during the Campanian, but in the early 20th century the true extent of the group was only just being revealed. Still, it was clear to Gilmore that at an estimated six feet in length, Brachyceratops was an unusually small ceratopsian. He proposed that it may have fed on different plants or occupied a different niche than larger contemporaries like Centrosaurus and Styracosaurus.

Reconstruction of Brachyceratops holotype skull. Plate from Gilmore 1917.

In 1917, most of the dinosaur mounts on display at NMNH came from fossils collected by Marsh for the US Geological Survey, and many represented species also on display in New York, Pittsburgh and New Haven. Accordingly, Gilmore was doubtlessly enthused by the prospect of displaying a dinosaur exclusive to Smithsonian. He awarded the task of creating a Brachyceratops mount to preparator Norman Boss, who would spend 345 working days on the project. Of the five individuals found in Montana, USNM 7953 was selected as the basis for the mount because it was the most complete, with the sacrum, pelvis, femora and complete set of caudal vertebrae found articulated in situ. Helpfully, Gilmore published a list of precisely which parts of the mount came from which individual specimen (see below). This was a marked contrast from some of his contemporaries at other museums, who would not bother to record such information, or even actively obscure how many disparate specimens they were using to build their mounts.

A helpful breakdown of the Brachyceratops mount from Gilmore 1922.

Boss based his restoration of Brachyceratops closely on the complete, articulated Monoclonius (=Centrosaurus) specimen (AMNH 5351) discovered by Barnum Brown in 1914. In particular, Boss replicated the angle of the scapulae and the number of vertebrae (22) on the American Museum of Natural History skeleton. Missing bones and portions thereof were sculpted in plaster, easily recognized by their solid color and smooth texture. Just as Gilmore and Boss had done with their 1905 Triceratops mount, the Brachyceratops was given strongly flexed elbows. According to Gilmore, a very large olecranon process on the ulna would have forced all ceratopsians into this somewhat awkward stance. Of particular note is the restoration of the skull, which was found shattered into dozens of pieces, many smaller than one inch. A close look at the specimen reveals how Boss painstakingly reassembled these fragments. Unfortunately, this is difficult in the exhibit hall because the mount is posed with the side of the skull that is mostly plaster facing visitors.

Norman Boss Brachyceratops courtesy Smithsonian archives

Norman Boss puts the finishing touches on the Brachyceratops mount. Photo courtesy of the Smithsonian Archives.

The completed Brachyceratops mount was placed on exhibit in 1922, on the same pedestal in the Hall of Extinct Monsters as the Triceratops. The substrate beneath the mount was colored and textured to match the Two Medicine Formation sandstone in which the fossils were found. Gilmore also prepared one of his charming models of Brachyceratops, mirroring the pose of the mount, but it is unclear whether it was ever exhibited.

Brachyceratops on exhibit with Triceratops. Plate from Gilmore 1922.

The Brachyceratops has remained on view through each subsequent renovation of the fossil halls, always placed close to Triceratops. This close association has prompted many visitors to mistake the diminutive Brachyceratops for a baby Triceratops, and in fact these visitors are on the right track. While Gilmore always described Brachyceratops as an unusually small but full-grown ceratopsian, Scott Sampson and colleagues confirmed in 1997 that all five specimens were juveniles. A century’s worth of new fossil discoveries has provided modern paleontologists with a thorough understanding of ceratopsian ontogeny, and characteristics like the unfused nasal horn clearly mark the mounted Brachyceratops as a young animal. Unfortunately, Gilmore’s Brachyceratops specimens lack any good diagnostic features that could link it to an adult form. According to Andrew McDonald, the most likely candidate is Rubeosaurus ovatus, which was, incidentally, discovered by Gilmore on a 1922 repeat trip to the Two Medicine site. Nevertheless, without the ability to recognize other growth stages of the same species, the name Brachyceratops is unusable and is generally regarded as a nomen dubium.

It is not difficult to surmise why the Brachyceratops would end up near the bottom of the list of mounts to include in a renovated gallery. It is not especially large or impressive, it doesn’t have a recognizable name (or any proper name at all, really) and it doesn’t tell a critical story about evolution or deep time. With limited space available and new specimens being prepped for display, little Brachyceratops will have to go. It’s not all bad, though. Taking these fossils off exhibit will make them more accessible to researchers, and allow them to be closely examined in all aspects for the first time in decades. Perhaps one day soon we will have a clearer idea of the identity of one of Gilmore’s great finds.

References

Gilmore, C.W. (1917). Brachyceratops, a Ceratopsian Dinosaur from the Two Medicine Formation of Montana, with Notes on Associated Fossil Reptiles. Washington, DC: US Geological Survey.

Gilmore, C.W. (1922). The Smallest Known Horned Dinosaur, Brachyceratops. Proceedings of the US National Museum 63:2424.

Gilmore, C.W. (1930). On Dinosaurian Reptiles from the Two Medicine Formation of Montana. Proceedings of the US National Museum 77:2839.

McDonald, A.T. (2011). A Subadult Specimen of Rubeosaurus ovatus (Dinosauria: Ceratopsidae), with Observations on other Ceratopsids from the Two Medicine Formation. PLoS ONE 6:8.

Sampson, S.D., Ryan, M.J. and Tanke, D.H. (1997). Craniofacial Ontogeny in Centrosaurine Dinosaurs: Taxonomic and Behavioral Implications. Zoological Journal of the Linnean Society 12:1:293-337.

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Filed under dinosaurs, exhibits, Extinct Monsters, field work, fossil mounts, history of science, marginocephalians, museums, NMNH, reptiles

Tagged as dinosaurs, Extinct Monsters, fossil mounts, museums, NMNH, Smithsonian

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