Hello new followers!

Apatosaurus and Camarasaurus at the Peabody Museum of Natural History. Photo by the author.

Apatosaurus and Camarasaurus at the Peabody Museum of Natural History. Photo by the author.

Thanks to the Diplodocus post being featured on Freshly Pressed, the number of people following this blog has increased fourfold in 24 hours. Welcome, everyone, and thanks for your interest! I’ve been using this blog to explore the world of mounted fossil skeletons in museums. These exhibits fascinate me because they are effectively installation art in the service of science, and what’s more, many have taken on a second life as cultural artifacts over the course of their decades on display.

Here is a sampling of key posts that have been reasonably popular…or which I am not yet completely embarrassed by:

A Primer on Fossil Mounts

Museums and the Triceratops Posture Problem – Parts One and Two

Displaying the Tyrant King – Parts One, Two, and Three

The Osborn Problem

History of Fossil Displays at the Smithsonian

The Calvert Marine Museum’s Big Foam Shark

Juan Bautista Bru and the First Fossil Mount

First Full-Sized Dinosaurs: From Crystal Palace to Hadrosaurus

Chicago’s Half-Finished Sauropod

In Defense of New Museums

Beating the Orthogenetic Horse

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Filed under fossil mounts, history of science, museums

Museums and the Triceratops Posture Problem – Part 2

Triceratops at the National Museum of Natural History.

Triceratops “Hatcher” at the National Museum of Natural History. Photo by the author.

Back in July, I wrote about how the forelimb posture of ceratopsian dinosaurs like Triceratops has puzzled paleontologists for more than a century. Most quadrupedal dinosaurs held their front legs straight under their bodies, and it would make sense if Triceratops and its kin did the same. However, when researchers attempted to physically articulate skeletons for museum displays, they found that that the humerus would only fit properly with the scapula if it projected horizontally from the torso – like the sprawling limbs of a lizard. Over the years, new specimens, new research methods, and new technologies have all been used to help resolve this conundrum, but a consensus has not yet been reached. Of particular interest to me is the unusually central role mounted skeletons in museums have played in this biomechanical mystery. The previous post covered the historic Triceratops mounts; this entry will take a look at some more recent Triceratops displays in American museums.

The Hatcher Project

In 1998, a visitor looking at the Triceratops mount at the National Museum of Natural History happened to sneeze. To her alarm, the sneeze was enough to knock a small fragment of bone off the pelvis and onto the floor. The visitor thoughtfully informed security, and after a thorough conservation assessment by Kathy Hawks, it was determined that the 93-year-old mount needed to come off exhibit, and soon. The delicate fossils had served valiantly through 23 presidential administrations, but now it was time for the skeleton to be disassembled and preserved for posterity.

Retiring the classic Triceratops gave Ralph Chapman, head of the Museum’s Applied Morphometrics Laboratory, an opportunity to take on a project he had been germinating for some time. Chapman wanted to demonstrate the potential of 3-D scanning technology for paleontology research by creating a high-resolution digital duplicate of a dinosaur skeleton. Today, the process of making and studying digital copies of fossils is both widespread  and remarkably straightforward, but in the late 1990s it was practically science fiction. Nevertheless, the historic Triceratops was an ideal digitization candidate for several reasons. First, the digital assets would reduce handling of the delicate and aging original fossils. Second, exact copies of the scanned bones could be made from milled foam and plastics to create a replacement exhibit mount. Finally, a digital Triceratops would be a great opportunity to revisit the ceratopsid posture problem in a new way.

digital hatcher

A rendering of the digital Hatcher. Source

The ensuing Hatcher Project (the Triceratops was named in honor of John Bell Hatcher, who found the original fossils in the late 19th century) was a collaboration between Museum staff and several industry experts, including Lisa Federici of Scansite 3-D Services and Arthur Andersen of Virtual Surfaces, Inc. The first step was to place stickers on 100 key points on the Triceratops. These points were recorded with a surface scanner, so that the historic mount could be digitally recreated in its original pose. After that, fossil preparators Steve Jabo and Pete Kroehler carefully dismantled the skeleton. Each bone from the skeleton’s right side* was then scanned individually, producing 20 gigabytes of data (you’re supposed to gasp…again, this was the late 90s).

*Bones from the right side were mirrored to reproduce the left half of the skeleton. 

Since the original mount had been a somewhat disproportionate composite, the team made a few changes when building the new digital Hatcher. Some elements, including the undersized skull, were enlarged to match the rest of the skeleton. In addition, parts that had either been sculpted or were not actually Triceratops bones – such as the dorsal vertebrae and the hindfeet – were replaced with casts acquired from other museums. The result was the world’s first complete digital dinosaur, and shortly afterward, the first full-sized replica skeleton generated from digital assets.

Updated "Hatcher" mount's rarely seen right side. Source

Hatcher’s seldom seen right side was briefly exposed recently, before the mount was moved to a temporary second floor location. Source

In April 2000, the Hatcher team convened at NMNH to determine how the new replica mount would be posed. Chapman, Jabo, and Kroehler were joined by Kent Stevens of the University of Oregon, Brenda Chinnery of Johns Hopkins University, and Rolf Johnson of the Milwaukee Public Museum (among others) to spend a day working with a 1/6th scale model produced by stereolithography specialist Jason Dickman. The miniature Hatcher allowed the researchers to physically test the skeleton’s range of motion without the difficulty of manipulating heavy fossils.

The day was full of surprises. The team was impressed by the wide range of motion afforded by the ball and socket joint connecting the Triceratops skull to the atlas. They also found that the elbow joints could lock, which may have been helpful for shock absorption when the animal smashed things with its face. Nevertheless, when it came time to articulate the humerus and scapula, the team essentially validated Charles Gilmore’s original conclusion that sprawling forelimbs worked best (although the new Hatcher mount stands a little straighter than the historic version, and a lot straighter than the New York Triceratops). While other paleontologists had used indirect evidence (like evenly spaced trackways and wide nasal cavities for sucking down lots of oxygen) to support the idea that Triceratops was a straight-legged, fast-moving rhino analogue, articulating the actual bones showed once again that ceratopsid forelimbs had to sprawl.

Houston and Los Angeles Mounts

LACM Triceratops mount. Photo by Heinrich Mallison, many more here.

LACM Triceratops mount. Photo by Heinrich Mallison, many more here.

Hatcher is the Triceratops I am best acquainted with, and I can’t help but think of it as the definitive example of this animal. However, two new Triceratops mounts demonstrate a radically different take on ceratopsid posture. In 2011, the Natural History Museum of Los Angeles County completed a thoroughly renovated dinosaur hall, which features a brand-new Triceratops mount at its entrance. Like Hatcher, this skeleton is a composite of several specimens, in this case excavated in Montana by LACM teams between 2002 and 2004. Phil Fraley Productions, the exhibit fabrication company behind Sue and the Carnegie Museum dinosaurs, was responsible for mounting the fossils. The primary specimen (LACM 141459, which provided the skull and right forelimb) is notable because it included a completely intact and articulated front leg. Although the analysis of this important find has yet to be published, exhibit curator Luis Chiappe tellingly chose an erect, rather than sprawling, forelimb posture.

Meanwhile, the Houston Museum of Nature and Science opened its colossal, 30,000 square foot Hall of Paleontology in 2012. Among the dozens of mounted skeletons on display is Lane, reportedly the most complete Triceratops ever found. The museum purchased the skeleton from the Black Hills Institute, and the company also constructed the display mount. Robert Bakker, who curates the Hall of Paleontology, specifically requested that Lane be given a straight-legged, trotting pose. With two legs off the ground, this display emanates strength and speed.

"Lane" at Houston Museum

“Lane” at Houston Museum of Nature and Science. Source

So how did the Los Angeles and Houston exhibit teams manage to construct plausible-looking, straight-legged Triceratops mounts? Since full descriptions of either specimen have not been published, it’s hard to say for sure. From the look of it, however, the new mounts both have narrower, flatter rib cages (as suggested by Paul and Christiansen), which allows more room for the elbow. Likewise, the shoulder girdles are lower than Hatcher’s, and they seem to have been rotated closer to the front of the chest. Also note that the forelimbs of the Los Angeles and Houston mounts are not completely erect – they are strongly flexed at the elbow, as is typical of many quadrupedal mammals.

These new mounts don’t mean the Triceratops posture problem is resolved, though. The angle of the ribs and the position of the scapula are apparently both touchy subjects, so alternate interpretations are sure to arise in the future. After all, Triceratops forelimb posture isn’t just an esoteric bit of anatomical trivia: it has major implications for the speed and athleticism of an extremely successful keystone herbivore. Understanding the limitations on this animal’s movement and behavior can contribute to our understanding of the ecosystem and environmental pressures in late Cretaceous North America. As such, I am eagerly awaiting the next round in this 100-plus year investigation.

A big thank you to Rebecca Hunt-Foster and Ralph Chapman for sharing their time and expertise while I was writing this post!

References

Chapman, R. Personal communication.

Chapman, R., Andersen, A., Breithaupt, B.H. and Matthews, N.A. 2012. Technology and the Study of Dinosaurs. The Complete Dinosaur, 2nd Edition. Bloomington, IN: Indiana University Press.

Fujiwara, S. and Hutchinson, J.R. 2012. Elbow Joint Adductor Movement Arm as an Indicator of Forelimb Posture in Extinct Quadrupedal Tetrapods. Proceedings of the Royal Society 279: 2561-2570.

Hunt-Foster, R. Personal communication.

Paul, G.S. and Christiansen, P. 2000. Forelimb Posture in Neoceratopsian Dinosaurs: Implications for Gait and Locomotion. Paleobiology 26:3:450-465.

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

The Diplodocus seen around the world

1st cast in spot of honor

The first cast of the Carnegie Diplodocus holds court at London’s Natural History Museum. Source

The story of Andrew Carnegie’s Diplodocus will surely be well known to most readers. As the legend goes, Carnegie the millionaire philanthropist saw a cartoon in the November 1898 New York Journal depicting a sauropod dinosaur peering into the window of a skyscraper. He immediately contacted the paleontology department at the newly established Carnegie Museum of Natural History in Pittsburgh, and offered ample funding to find a sauropod skeleton for display. So began a frantic competition among the United States’ large urban museums to be the first to collect and mount a sauropod – the bigger the better.

The American Museum of Natural History was first across the finish line, unveiling their composite “Brontosaurus” in February of 1905. By that time, the Carnegie team had already found a sauropod skeleton of their own, a Diplodocus, near Medicine Bow, Wyoming. Unfortunately, they had nowhere to display it, as the Carnegie Museum building was still far from finished. Unwilling to be bested by his New York competition, Andrew Carnegie offered his chum King Edward VII a complete plaster replica of the Diplodocus, and hired a team of modelmakers to help make it happen. The arrival of the facsimile Diplodocus at the British Museum (now the Natural History Museum) in London was celebrated with a white tie event presided over by Carnegie and Baron Avebury, who spoke on behalf of the king. The London Diplodocus was on display two months after the AMNH “Brontosaurus”, and the original skeleton was unveiled in Pittsburgh in 1907.

diplodocus_nocopyright

In March 1905, a classy shindig celebrated the arrival of the first replica Diplodocus in London.

That’s usually where the Diplodocus story ends, with a footnote that nine more Diplodocus replicas were later manufactured and presented to heads of state throughout Europe and Latin America. I’d like to explore those subsequent displays in more detail. The Carnegie Diplodocus was the first mass-produced dinosaur, and by 1932 it appeared in no less than ten virtually identical displays across three continents. Taylor characterizes Carnegie’s sauropod as “the single most viewed skeleton of any animal in the world”, and its scientific, social, and even political ramifications are both wide-reaching and fascinating.

Building a Sauropod

The original CMNH Diplodocus mount, in the hall built specifically to accomodate it. Source

The real CM 84 has been displayed in Pittsburgh since 1907. Source

The Diplodocus in question is specimen CM 84, recovered in 1899 in Albany County, Wyoming. The skeleton was about 60% intact and remains one of the most complete sauropod specimens ever found. The ubiquitous John Bell Hatcher described the fossils in 1901, coining the new species Diplodocus carnegiei after the project’s benefactor. Arthur Coggeshall of the Carnegie Museum was primarily responsible for preparing and casting the fossils. He was initially supervised by Hatcher, but William Holland took over when Hatcher died in 1904. Holland deferred to Hatcher’s judgement in most cases, although he was not shy about voicing his disagreement. For example, Hatcher had reconstructed the Diplodocus forefeet with slightly elevated digits, but Holland (incorrectly) thought they should be flat and splayed.

As is typical of dinosaur mounts, the incomplete primary specimen was supplemented with other fossils to produce a full skeleton. The skull, for instance, was a cast of USNM 2673, a specimen that was until recently on display at the Smithsonian. A number of missing bones, including most elements of the forelimbs, were sculpted using a smaller Diplodocus specimen for reference. Although it took longer to produce than the AMNH “Brontosaurus”, contemporary paleontologists generally agreed that Carnegie’s Diplodocus was the superior sauropod mount. Not only was it’s pose more natural and lifelike, but the underlying steel armature was cleverly hidden. It’s difficult to overstate the challenges of assembling a mounted skeleton on this scale, and in its day the Diplodocus was the best in the world.

Roll Call

dip_mexico

The Chopo University Museum in Mexico City received the 9th Diplodocus cast in 1929. Source

As mentioned, the first replica Diplodocus was unveiled in London in 1905, and the original fossils were ready for display in 1907. French and German dignitaries were present at an event in Pittsburgh celebrating its completion, and Andrew Carnegie promised both countries Diplodocus casts of their own. Once again, Coggeshall and Holland led the creation of the new mounts, a task they would repeat many times in the years to come. Playing precisely to cartoonish national stereotypes, the Germans provided a detailed plan and ambitious schedule for the project, while the French acted coy, then threw a lavish party when the mount was ready. Diplodocus replicas were on display at the National Natural History Museum in Paris and the Humboldt Museum in Berlin before the end of 1908, but the Pittsburgh team already had orders for a new batch of mounts. By early 1910, three new Diplodocus were on exhibit at the Museum for Paleontology and Geology in Bologna, Italy, the Natural History Museum in Vienna, Austria, and the Zoological Museum in St. Petersburg, Russia. The La Plata Museum in Buenos Aires, Argentina and the National Museum of Natural Science in Madrid, Spain received their Diplodocus mounts in 1912 and 1913, respectively, bringing the total number of replicas up to eight by the onset of World War I.

The war put a damper on this friendly exchange of dinosaurs, and Carnegie’s death in 1919 brought the Diplodocus diaspora to a temporary end. However, in 1929 Louise Carnegie, wife of Andrew, commissioned an additional cast as a gift for Alfonso Herrera of the Chopo University Museum in Mexico City. Herrera originally asked for a bronze cast for outdoor display, but when this proved prohibitively expensive, a plaster version was produced instead. In 1932, the Carnegie Museum traded a Diplodocus replica for a collection of German fossils from the Paleontological Museum in Munich. This copy has never been mounted or displayed. The last Diplodocus cast from the original molds was forged in 1957. Made from concrete, this mount was displayed outdoors for many years at the Utah Field House Museum in Vernal, Utah.

goofy vernal field house concrete cast

The 11th and final facsimile Diplodocus made from the original molds was this concrete version, on exhibit in Vernal, Utah for many years.

Most of the historic Diplodocus mounts remain on display today. The London Diplodocus was taken off exhibit during World War II, but in 1979 it was given a position of honor in the museum’s entrance hall. Later, it was completely restored and remounted with its tail held aloft. The Berlin, Buenos Aires, and Bologna Diplodocus mounts have also been upgraded with modern poses, but the others retain their historic, tail-dragging posture, looking exactly as they did a century ago. The St. Petersburg mount was circulated among a number of Russian museums, and may have been destroyed in an effort to make new molds from the bones (Edit: The Russian mount is still on display at the Orlov Museum for Paleontology – see comments). The concrete Diplodocus in Vernal has likewise been retired, but it was used to create two new casted skeletons, now on display in Utah and Nevada.

Opportunities for Science

St. Petersburg

The weird bow-legged Diplodocus in St. Petersburg looks more like the original USNM Triceratops than Tornier’s take on the sauropod.  Source

The sudden availability of identical Diplodocus skeletons presented an unusual opportunity for international scientists, allowing researchers based thousands of miles apart to study and compare notes on the same bones. Perhaps inevitably, a few European scientists were not happy with Holland and Coggeshall’s take on the sauropod. The best-known dissenter was Gustav Tornier, who rejected the straight-limbed reconstruction of Diplodocus, arguing instead that the sauropod sprawled like a crocodile. The German scientist provided an illustration of this alternate stance, in which the poor dinosaur’s arms appear to project from the base of its neck. Holland responded with a particularly harsh rebuttal (backed by several European scientists), and Tornier declined to push the issue further in print.

Rather than risk Holland’s wrath in writing, in at least one case local researchers may have quietly modified their Diplodocus mount after the Americans installed it (Warning: speculation ahead). The St. Petersburg Diplodocus once sported bizarrely bowed forelimbs and a strongly arched back. Holland himself directed the assembly of each and every Diplodocus mount*, and based on his impassioned (and occasionally ad-hominem laced) writing on the subject, it seems quite unlikely that he would have permitted this deviation from his standard design. Even a request from the National Natural History Museum in Paris to curl the sauropod’s tail to save space met with some hand-wringing on his part, so I can only surmise that St. Petersburg mount was altered sometime after Holland’s work was finished.

*Holland was definitely present during the initial assembly of the St. Petersburg Diplodocus, as he more than once recounted an incident in which a Russian worker almost dropped one of the steel supports on him (Edit: This may not have happened – see comments).

Dinosaurs for everyone

La plata

Diplodocus cast number seven at the La Plata Museum in Buenos Aires. Source

The most lasting influence of the Carnegie Diplodocus is certainly it’s cultural impact. If any one specimen can be credited with inspiring the global popularity of dinosaurs, it was this one. Thanks to Carnegie, citizens of 11 different nations had their first opportunity to stand in the presence of a giant dinosaur, and to experience the scale and splendor of a creature that completely dwarfed any modern land animal. In every nation where a new Diplodocus was installed, the local press adored the creature, never failing to point out it’s tiny head and presumed stupidity. Diplodocus was an endearing oaf, and for a time, its name was synonymous with dinosaurs and prehistory in general.

What was the significance of Diplodocus to all these people? It’s difficult not to think of it as a vanity project for Andrew Carnegie*, an opportunity to rub shoulders with European royalty and flaunt his wealth and generosity. One might also consider the Diplodocus an expression of America’s economic and technological might, or perhaps a harbinger of the United States’ role in globalization and mass production. French writer Octave Mirbeau seemed to be thinking along those lines when he lamented the mighty dinosaur being reduced to a crass, populist display. According to Carnegie himself, however, the goal was nothing less than world peace: he wanted to bring people together over their shared enthusiasm for the dinosaur. Too bad World War I came along and ruined the sauropod love-in.

*If the accolades went to anyone’s head, it was Holland’s. During his world tour assembling sauropod mounts, he was given countless awards, including the French Legion of Honor and German Knight’s Cross. Holland carefully added each new medal to his portrait at the Carnegie Museum.

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

The original Diplodocus skeleton, now remounted in a livelier pose at the Carnegie Museum. Photo by the author.

On both sides of the Atlantic, Diplodocus was a shared point of reference and a beloved symbol. Most commonly, Diplodocus was the butt of a joke: from politicians to athletes to heavy machinery, anything big and slow and not especially bright was likened to the dinosaur. My favorite anecdote on the subject comes from Nieuwland: during World War I, soldiers from different nations with different languages had the word “Diplodocus” in common, and used it to describe the heavy, plodding tanks.

Today, we think of Diplodocus and its ilk very differently. Sauropods weren’t ungainly dolts – they were surprisingly nimble and extremely successful megaherbivores, unchallenged in their dominance for 140 million years. Still, it’s difficult to think of single fossil that has matched the global cultural impact of CM 84. There are far more copies of Stan the T. rex on display, and Sue is widely known by name, but really, the only contender that even comes close is Archaeopteryx. With eleven versions still on display, Carnegie’s legendary Diplodocus lives on.

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.

Holland, W.J. 1906. The osteology of Diplodocus Marsh with special reference to the restoration of the skeleton of Diplodocus carnegiei Hatcher, presented by Mr. Andrew Carnegie to the British Museum, May 12, 1905. Memoirs of the Carnegie Museum. Vol. 2, No. 6, 225-278.

Nieuwland, I. 2010. The colossal stranger: Andrew Carnegie and Diplodocus intrude European Culture, 1904-1912. Endeavour. Vol 34, No. 2.

Taylor, M.P. 2010. Sauropod dinosaur research: a historical review. Geological Society, London, Special Publications. Vol. 343, pp. 361-386.

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

Exhibit Review: Dinosaur Mysteries at the Maryland Science Center

First, let me assure you that the posts on major fossil exhibits and Triceratops mounts I’ve promised are definitely in the works, and I should be finishing them soon(ish). In the meantime, here’s a quick write-up of my recent trek to the distant land of Baltimore’s inner harbor, home of the Maryland Science Center and the “Dinosaur Mysteries” exhibit. In all seriousness, this exhibit has been open since 2004 and is less than 40 miles from me, so this visit was long overdue. What’s more, now that the Smithsonian’s fossil hall is closed for renovation, this is the largest dinosaur exhibit in the region, and will be the spot to see mounted dinosaur skeletons near Washington, D.C. for the next five years. Is it up to the task? Let’s find out.

Dinosaur Mysteries from the second floor. Photo by the author.

Dinosaur Mysteries from the second floor. Photo by the author.

At 15,000 square feet, Dinosaur Mysteries isn’t a huge exhibit, but it’s pretty dense with content. There are a lot of displays and interactives crammed into into the space, including no less than 12 free-standing mounts and life-sized sculptures of Astrodon* and Acrocanthosaurus. This venue is a science center, not a natural history museum, so the exhibit is mostly aimed at kids and families. That said, there’s still plenty for adult visitors to enjoy (the rest of the museum is purely for kids, though…if you don’t have any, I’d recommend taking advantage of the half-priced Friday evenings).

*Alright, it’s really a sculpture of Giraffatitan standing in for the poorly known Astrodon.

Among the mounted skeletons (all casts), expect to see Tyrannosaurus (Peck’s Rex, to be specific), Tarbosaurus, Giganotosaurus, Compsognathus, Herrerasaurus, Protoceratops, what used to be called “Dilophosaurus sinensis”, and plenty of others. The offerings are a little theropod heavy (and a little tyrannosaur heavy, in point of fact), but they certainly don’t fail to impress. Sadly overlooked by most visitors are some lovely genuine Maryland fossils, including an Astrodon femur that is the largest dinosaur bone found east of the Mississippi River.

Full skeleton cast of Peck's Rex, accompanied by skull cast of the Nation's T. rex. Photo by the author.

Full skeleton cast of Peck’s Rex, accompanied by skull cast of the Nation’s T. rex/Wankel Rex. Photo by the author.

Thematically, Dinosaur Mysteries is all about answering questions through observation and deduction. The press release asserts that there are over two dozen interactives available, and indeed, visitors are invited throughout the exhibit to compare, contrast, and even measure fossils in order to draw conclusions about dinosaurs’ lives. Most of the “mysteries” are of the safe variety, tackling issues that are either soundly resolved or were never really issues to begin with (think “are birds dinosaurs” or “was Tyrannosaurus a scavenger or a predator”). Experts might be a bit blasé about these questions, but they nevertheless serve to get visitors thinking about how scientists draw conclusions. I go back and forth on this, but generally I find it helpful to embrace what visitors are already familiar with, at least as a starting point, rather than shutting out their frame of reference entirely.

Birds are dinosaurs, did you know?

This may come as a shock, but birds are dinosaurs. Photo by the author.

Other interactive components include a cool champsosaur skeleton puzzle, and a tabletop sandbox to dig in. I would have liked to see more interactivity with the dinosaur mounts themselves, since they’re the most visually impressive part of the exhibit. For example, there are no less than three Tyrannosaurus skulls on display, all from different specimens. That’s a great opportunity to compare the eccentricities of each individual, perhaps considering age differences, sexual dimorphism, pathology, or even erroneous reconstruction (looking at you, Wankel Rex rostrum). With some guidance, I reckon most visitors would do well with that, and it would push them closer to how paleontologists actually study fossils.

Astrodon and Acrocanthosaurus sculptures with Bored Dad #2. Photo by the author.

Astrodon and Acrocanthosaurus sculptures, with a Bored Dad. Photo by the author.

Apparently included in those two dozen interactives are a number of video terminals. As I’ve ranted before, videos are not interactive, even if you get to press a button to start it. That said, I’m actually of two minds about these. The videos, which are mostly interviews with paleontologists like Tom Holtz, Kristina Curry-Rogers, and Chris Morrow, were fascinating. I enjoyed hearing about the presumed purpose of Tyrannosaurus gastralia, what can and cannot  be presumed from dinosaur trackways, and especially the decision-making process behind posing a T. rex mount. However, these videos are also quite long, and rather unedited. The speakers ramble, repeat themselves, and generally er and um through their spiels. It’s quite a bit like chatting with a scientist about their work in person, actually, and I’m always in favor of giving science a human face. On the other hand, the exhibit team probably could have tightened these up.

What used to be called "Dilophosaurus sinensis" and friends. Photo by the author.

What used to be called “Dilophosaurus sinensis” and friends. Photo by the author.

Overall, I was pretty pleased with Dinosaur Mysteries. It’s not a large-scale fossil hall at a major research museum, but it’s still cool to experience and the science being taught is generally very good. If you’ve got kids who are bummed that the Smithsonian fossil hall is closed (don’t forget that The Last American Dinosaurs is opening this fall, though), this is definitely a worthy substitute. For adults,  keep in mind that you aren’t the Maryland Science Center’s target audience, but if you appreciate the artistry of a well-made dinosaur exhibit, Dinosaur Mysteries is still worth checking out.

PS: There are a few additional photos on my tumblr page.

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Filed under dinosaurs, exhibits, fossil mounts, museums, reviews, science communication

Museums and the Triceratops Posture Problem – Part 1

The Triceratops in the Hall of Extinct Monsters, circa 1911. Photo from NMNH on flickr.

The world’s first Triceratops mount at the United States National Museum, built in 1905. Photo courtesy of the Smithsonian Institution Archives.

We know more about dinosaurs today than previous generations of researchers would have ever thought possible. Who would have guessed that in the 21st century, we would have direct evidence for the color of some species, or a detailed understanding of the life history and ontogeny of others? Modern paleontologists can delve deeper into the biology and ecology of extinct animals than ever before, so it comes as a surprise when a very basic question about dinosaur physiology has gone without a definitive answer for well over a century.

For 125 years, paleontogists have struggled to understand how large ceratopsids like Triceratops held their forelimbs. Usually, someone with a good understanding of anatomy can assemble a tetrapod skeleton without much difficulty. Vertebrates are all built along the same basic body plan, and bones fit together in the same general way. However, the forelimb bones of Triceratops and its relatives are quite perplexing. The head of the humerus, which articulates with the scapula, is off-center and extends backward from the shaft. Meanwhile, the lesser tubercle, a tiny nubbin on a human humerus, is enormous and boxy. Taken together, these two traits make it so that if Triceratops held its arm erect and under its body, like most dinosaurs did, the humerus would either puncture the rib cage or be completely dislocated from the shoulder. The simplest way to solve this is to orient the humerus so that the arms project at right angles from the torso, like the sprawling limbs of a lizard. But this just looks wrong. First, ceratopsid hindlimbs are plainly meant to stand straight up. Sprawling forelimbs make Triceratops look mismatched, like the front end a tortoise sewn was to the back end of a rhino. Second, and perhaps more importantly, a sprawling posture would drastically inhibit speed and maneuverability in what is otherwise a very powerfully-built animal. The posture of Triceratops and its kin would ultimately have had a dramatic impact on the animal’s behavior, lifestyle, and ecological role.

Paleontologists haven’t spent the last century just scratching their heads over this problem. Ceratopsid forelimbs have inspired a considerable amount of research over the years, as scientists continue to develop new methods and new tools to explore the biomechanics of prehistoric animals. New technologies have been developed and refined specifically to help determine how Triceratops and its relatives walked and stood. Nevertheless, my intent with this post is not to thoroughly recount the history of ceratopsid forelimb research (if you’re interested, most of the articles referenced below are freely available online). Instead, I’d like to explore the central role museum displays have played in this debate. An artist drawing a two-dimensional image of Triceratops can fudge the orientation of the limbs (and many have), but the team building a mounted skeleton needs to know exactly how to articulate the bones. The ceratopsid posture question first arose in the process of building a mounted Triceratops skeleton for display, and museum mounts continue to be referenced by researchers looking to “ground truth” their ideas. While museum mounts usually exist primarily for education and display, in the case of the ceratopsid forelimb question these exhibits have long been central to the process of studying fossil evidence and creating knowledge.

Early Reconstructions

Marsh's 1891 restoration of Triceratops.

Marsh’s 1888 restoration of Triceratops.

O.C. Marsh published the first illustrated reconstruction of a Triceratops skeleton in 1888. Marsh was legendary in his attention to detail, and the restoration holds up reasonably well today – better, in fact, than his illustrations of Stegosaurus and “Brontosaurus.” Contemporary scientists had no complaints, even though Marsh had given the Triceratops vertical forelimbs. Other dinosaurs had erect limbs, as does the superficially similar modern rhino, so why shouldn’t Triceratops? Marsh’s reconstruction was brought to three-dimensional life in 1901, when the Smithsonian Institution commissioned a life-sized papier mache replica of a Triceratops skeleton for the Pan-American Exposition in Buffalo. Since the model was hand-sculpted, not casted from original fossils, artist F.A. Lucas had no trouble making Triceratops stand up straight, exactly as portrayed by Marsh. The model appeared again at a Smithsonian exhibit in St. Louis, but was apparently lost or destroyed shortly afterwards. In its place, newly hired United States National Museum preparator Charles Gilmore began work on a mounted Triceratops skeleton composed of original fossils.

St. Louis Expo

Straight-legged Triceratops model at the Pan American Expo in St. Louis. Source

Gilmore’s 1905 Triceratops mount was the first real skeleton of a ceratopsid ever assembled for display (first image). Like virtually all dinosaur mounts of the era, the skeleton was a composite of several specimens and a few sculpted pieces. All the Triceratops fossils at Gilmore’s disposal were collected by John Bell Hatcher in the late 19th century, and inherited by the Smithsonian as part of the Marsh collection. USNM 4842, a partial skeleton consisting mostly of a torso and pelvis, formed the basis for the mount, but at least six other individuals were also incorporated. Gilmore selected the skull because it was more complete and less distorted than the other Triceratops skulls available, but it was also on the small side compared to the body. Likewise, the left humerus was about 40% smaller than the right, and conspicuously three-toed Edmontosaurus hindfeet were used (no Triceratops feet had been found at the time). In the process of building his Triceratops, Gilmore had to make several changes to the idealized Triceratops envisioned by Marsh, most notably the orientation of the forelimbs. Not only was it apparently impossible to articulate the humerus in an upright position, but as Gilmore explained it, “a straightened form of leg would so elevate the anterior portion of the body as to have made it a physical impossibility for the animal to reach the ground with its head.”

The American Museum of Natural History produced their own Triceratops mount in 1923. Like its USNM predecessor, the AMNH Triceratops was a composite of several specimens. AMNH 5033, discovered by Barnum Brown in Montana and consisting of most of the dorsal vertebral column, ribs, and pelvic girdle, made up the largest portion of the mount. The skull was recovered by Charles Sternberg in Wyoming, and many of the appendicular bones were sculpted or cast from Smithsonian specimens. Preparator Charles Lang spent over 263 working days on the project, and much of that time was reportedly spent puzzling over the forelimbs. Lang studied living and preserved specimens of a variety of tetrapods, including rhinos, lizards, crocodiles, and tortoises, trying to find a living analogue for the strangely shaped ceratopsid bones. He ended up articulating the forelimbs so that they were even more widely splayed than Gilmore’s reconstruction, to the point that the back of the Triceratops slopes dramatically forward, and the head is almost dragging along the ground. In an accompanying paper, Henry Osborn asserted that “nothing short of a horizontal humerus and completely everted elbow would permit proper articulation of the facets.” By way of explanation, Osborn offered that this posture might have been helpful in withstanding a frontal impact.

triceratops

American Museum of Natural History Triceratops mount, circa 1959. Photo courtesy of the AMNH Research Library.

Together, the Washington and New York Triceratops mounts, with their mismatched tortoise-in-the-front, rhino-in-the-back posture, would come to define both popular and scientific conceptions of ceratopsids for the better part of a century. Other museums followed Gilmore and Lang’s lead and built sprawling ceratopsids of their own, including Richard Lull’s 1929 Centrosaurus at the Peabody Museum of Natural History and Kenneth Carpenter’s 1986 Chasmosaurus at the Academy of Natural Sciences. Even as recently as 1995, AMNH curators chose not to change a single bone on the historic Triceratops mount while modernizing their exhibit.

Voices of Dissent

Robert Bakker was one of the first to challenge the ceratopsid forelimb orthodoxy. In 1986, Bakker criticized Gilmore and Lull’s museum mounts and resurrected Marsh’s original interpretation of a straight-legged Triceratops. His reasoning was that the ceratopsid glenoid fossa (the concavity on the scapula that holds the head of the humerus) was more like the narrow cup of a horse or rhino than the wide trough of a lizard. Bakker went as far as to suggest that Triceratops and its kin might have been able to run or even gallop. Gregory Paul and others piled on, arguing that earlier researchers had run into trouble articulating Triceratops forelimbs because they had made the ribcage too broad. If the ribs were articulated so that the animal had flat flanks, the elbow apparently wouldn’t get in the way. Additional evidence for an upright stance came from a set of ceratopsid trackways described by Martin Lockley and Adrian Hunt. The trackways showed forefeet in line with the hindfeet, suggesting that front and back legs were not mismatched, after all.

This cast of the AMNH Triceratops at the Field Museum replicates the sprawling posture. Photo by the author.

This cast of the AMNH Triceratops at the Field Museum replicates the sprawling posture of the original. Photo by the author.

However, paleontologists like Peter Dodson were unmoved by these new arguments. Dodson proposed that the trackways had been misinterpreted: since ceratopsids are wider at the hips than at the shoulders, evenly spaced front and back prints should imply that the animal was holding its forelimbs out farther than its hindlimbs. Dodson was concerned that the rhino analogy was being taken too far: Triceratops looked like a rhino, so reasearchers were trying their hardest to make it move and behave like a rhino.

As Kenneth Carpenter explained in a comment last year, dinosaurs can do anything on paper, but physically assembling a skeleton forces you to confront the reality of what the bones can and cannot do. In the last decade, two new Triceratops mounts provided paleontologists the opportunity to re-explore this process, with more complete specimens and modern technology at their disposal. Next time, we’ll take a look at what the new Triceratops displays at the National Museum of Natural History and the Los Angeles County Natural History Museum can tell us about ceratopsid posture and lifestyle.

References

Bakker, R.T. 1986. The Dinosaur Heresies: New Theories Unlocking the Mystery of Dinosaurs and Their Extinction. New York, NY: Citadel Press.

Dodson, P. 1996. The Horned Dinosaurs: A Natural History. Princeton, NJ: Princeton University Press.

Fujiwara, S. 2009. A Reevaluation of the Manus Structure in Triceratops (Ceratopsia: Ceratopsidae). Journal of Vertebrate Paleontology 29:4:1136-1147.

Fujiwara, S. and Hutchinson, J.R. 2012. Elbow Joint Adductor Movement Arm as an Indicator of Forelimb Posture in Extinct Quadrupedal Tetrapods. Proceedings of the Royal Society 279: 2561-2570.

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

Makovicky, P. 2012. Marginocephalia. The Complete Dinosaur, 2nd Edition. Eds. Brett-Surman, M.K., Holtz, T.R. and Farlow, J.O. Bloomington, IN: Indiana University Press.

Osborn, H.F. 1933. Mounted Skeleton of Triceratops elatus. American Museum Novitates 654:1-14.

Paul, G.S. and Christiansen, P. 2000. Forelimb Posture in Neoceratopsian Dinosaurs: Implications for Gait and Locomotion. Paleobiology 26:3:450-465.

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

Framing Fossil Exhibits, Part 1

This post started out as a review of “Evolving Planet”, the expansive paleontology exhibit at the Field Museum of Natural History. The short version is that it’s very good exhibit constrained by a somewhat frustrating layout. We’ll get back to that eventually, but first it’s worth considering the purpose of large-scale fossil exhibits in a more general sense.

Fossils, particularly the mounted skeletons of dinosaurs and other prehistoric animals, have been central to the identity of natural history museums since the late 19th century. In the early days, public exhibits were afterthoughts to the primary work of the museum (research and curation of collections), and if there was any logic behind their layout, it was an aesthetic logic. Typically posed in neutral, trophy-like stances on centrally-situated pedestals, mounted skeletons were the highlights of a natural history display for most visitors. For anyone not trained in comparative anatomy, however, these exhibits ultimately amounted to prehistoric pageantry. People could marvel at the great size of the animals, but there was very little to be learned besides the names of the species in question.

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

A typically random assortment of fossil specimens at the Field Colombian Museum, ca. 1898. Image courtesy of the Field Museum Photo Archives.

These days, we try to do better. Exhibits are designed with a clear narrative structure, as well as specific learning goals for the audience. The focus of the narrative varies depending on the exhibit and the team behind it, but most modern natural history exhibits are explicitly designed to answer “how” as well as “what.” For paleontology displays, this means telling the story of life on Earth while also communicating how scientists collect and interpret evidence to put that story together. Crafting an exhibit has been compared to writing a popular nonfiction book, except designers are using the three-dimensional space of the exhibition hall as their medium. In this way, modern exhibits are more about ideas than specimens, or at least, the specimens are present primarily to illustrate the major scientific principles being communicated.

That’s how it works on paper, anyway. Despite this focus on education (and institutional mandates to provide learning opportunities for the widest possible audience), visitor surveys show that dinosaur pageantry is still the default mode of understanding for the majority of people passing through paleontology exhibits. No matter how carefully we craft our stories, most visitors still leave these displays recalling little more than a list of cool specimens they saw. Dinosaur pageantry has its place and can be employed for good. Dinosaurs and other prehistoric animals are undeniably impressive and spectacular, and it is absolutely worth taking advantage of that fact. We want people to pay attention to science, and in that respect mounted skeletons of favorite dinosaurs are great ambassadors to the world of research and discovery. The challenge is getting past the attention-grabbing stage. Prior experience has led visitors to expect that dinosaur pageantry is all paleontology has to offer, and many seem unprepared or unwilling to commit to a deeper understanding.

peabody mammals

The great hall at the Peabody Museum of Natural History, one of the last unmodified early 20th century fossil displays in the US. Photo by the author.

So are these people just hopeless rubes? Should exhibits be tailored only to visitors that care enough to put in the effort to understand? It should go without saying that this condescending attitude is completely wrongheaded and goes against the very spirit of museums. Education is half about knowing your content and half about knowing your audience. If visitors are not picking up on the content as desired, then a reassessment of who those visitors are is in order. Many museum exhibits still seem to be pitched at interested adults traveling alone with all the time in the world. This is a good description of many of my museum visits, but I’m also part of an increasingly small fraction of museum visitors. Most people who come to natural history museums come in groups of friends or family, and these groups often represent a range of ages. What’s more, most visitor interactions while in the museum will not be with the exhibits, but with each other. For the typical visitor, the museum experience is primarily a social one.

With this demographic in mind, a textbook on the wall (or a long video lecture*) is the last thing natural history museum audiences need. Visitors are absorbing exhibit content while simultaneously navigating a complicated, unfamiliar space. In the case of parents, they are also monitoring the attention span, hunger, and bathroom needs of their charges. Caught up in this whirlwind of information, visitors frequently fall back on what they already know. In the case of paleontology exhibits, this often means identifying familiar dinosaurs and ignoring the more intellectually challenging contextual information.

*It’s worth pointing out that a long video is NOT an improvement over a long label. Transferring label copy to a video or computer terminal does not inherently make the exhibit more interactive or more interesting. In fact, when the disruptive noise and need to wait for the next showing are taken into account, poorly implemented multimedia is probably less useful than traditional text labels.

The challenge for exhibit design, then, is dealing with the fact that visitors are not passively ingesting information. Visitors passing through an exhibit pull out relevant pieces of information and filter them through the lens of their existing worldview. Exhibit designers want visitors to also learn new information and challenge their preconceptions, but it’s easy to go too far. Survey after survey has shown that visitors do not appreciate exhibits that force them to move (or think) on rails. For practical reasons noted above, few visitors are able to look at every display, watch every orientation video, and work through every interactive in the prescribed order. Visitors need flexibility in order to make the exhibit experience their own. Finding the balance between providing informative context and providing a customizable experience is quite challenging, and not every exhibit succeeds.

struggling to contain the dinosaurs

The dinosaur hall in “Evolving Planet” at the Field Museum. Photo by the author.

On top of that, paleontology exhibits are particularly difficult to design because of problems with relatability. The story of life on Earth is immense, complex, and frequently counter-intuitive. It’s not enough to just explain what happened, we have to explain the history and methodologies of the half-dozen scientific disciplines that have contributed to to our understanding of that narrative. Even something so basic as the numerical age of a given fossil taxon requires a deluge of explanation to convey how we know. And all of this needs to be conveyed concisely, without being alienating, overwhelming, or condescending. Most importantly, it has to be made relevant to what audiences already know and understand.

Over the years, major natural history museums have attempted a variety of organizational strategies for their fossil exhibits. Each of these has been an attempt to break the dinosaur pageantry barrier and to portray the true complexity and relevance of paleontological science. Some arrangements, like taxonomical organization, have generally fallen out of favor. Others, like chronological presentations of life through time, are reliable mainstays that have been re-imagined in varied ways at different institutions. Still others, including cross-sections of specific extinct ecosystems, biogeography, and environmental change over time are relatively new and untested.

Keeping everything in this meandering introduction in mind, the upcoming series of posts will explore the strengths and weaknesses of each approach from the perspectives of science communication, aesthetics, and for lack of a better term, hospitality for non-expert audiences. Stay tuned!

References

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

Falk, J.H. and Dierking, L.D. 1992. The Museum Experience. Washington, DC: Whalesback Books.

Wands, S., Donnis, E. and Wilkening, S. 2010. “Do Guided Tours and Technology Drive Visitors Away?” History News 93:8:21-23.

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Filed under dinosaurs, exhibits, fossil mounts, history of science, museums, science communication

Extinct Monsters Updated

artists conception

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.

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Filed under dinosaurs, Extinct Monsters, fossil mounts, mammals, museums, NMNH