Tag Archives: fossil mounts

December 10, 2014 · 8:05 am

Extinct Monsters: Basilosaurus

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

The National Museum of Natural History houses the world’s most complete assemblage of fossil marine mammals. The crown jewel of this collection is assuredly the historic mounted Basilosaurus, which was until recently the only mount of its kind composed of original fossils. Since 2008, this ancestral whale has been suspended from the ceiling of the Sant Ocean Hall, but these fossils have actually been on near-continuous display for 120 years and counting. Technically this wasn’t the first time Basilosaurus fossils were used in a mounted skeleton (Albert Koch’s absurd chimera “Hydrarchos the sea serpent” preceded it by 60 years), but it was the first time this species was mounted accurately and under scientific supervision.

Basilosaurus was named by anatomist Richard Harlan in 1834. The name means “king lizard”, since he erroneously thought the bones belonged to a giant sea-going reptile. Richard Owen later re-identified the bones as those of a whale, and coined the new name “Zueglodon” (yoke tooth). While the International Code of Zoological Nomenclature decrees that the first published name must be used, late 19th century paleontologists apparently preferred to use Owen’s junior synonym.

Basilosaurus cast in the original USNM, now called the Arts and Industries Building. Photo courtesy of the Smithsonian Institution Archives.

In 1884 Charles Schuchert, an Assistant Curator at the United States National Museum, went to Clarke County, Alabama in search of “Zueglodon” remains. This would be the very first fossil-hunting expedition ever mounted by the Smithsonian. Decades earlier, Koch came to the same region to collect the fossils he used to assemble Hydrarchos, and local people had been familiar with the whale bones long before that.

Schuchert did not find the complete Basilosaurus skeleton he was looking for, but he did recover a reasonably complete, albeit fragmented, skull and jaw. He returned to Alabama in 1886 and collected an articulated vertebral column, a pelvis, and enough other elements to assemble a composite skeleton. Museum staff used the fossils to produce plaster casts, and combined them with sculpted bones to construct a replica “Zueglodon.” The whale was first unveiled at the Atlanta Exposition in 1895, before finding a home in the original United States National Museum (now the Arts and Industries Building). The 40-foot skeleton hung from the ceiling of the southwest court, with the original fossils laid out in a long case beneath it.

Basilosaurus as the centerpiece of the Hall of Extinct Monsters sometime before 1930. Photo courtesy of the Smithsonian Institution Archives.

In 1910, the USNM relocated to a larger building on the north side of the national mall, which is now of the National Museum of Natural History. The east wing of the new museum became the Hall of Extinct Monsters, and has been the home of fossil displays at the Smithsonian ever since. The Basilosaurus was selected as the centerpiece of the new display, as its great length and toothy appearance made it popular with visitors. In honor of the occasion, preparator James Gidley reworked the old plaster mount to incorporate Schuchert’s original fossils. A series of caudal vertebrae from a third Basilosaurus specimen was also used. Still labeled “Zueglodon”, the mount was completed in 1912, about a year after the Hall of Extinct Monsters first opened to the public. As Curator of Geology George Merrill explained, the wide-open floor plan of the new hall allowed visitors to walk all the way around the mount, and inspect its every aspect up close.

During the 1960s and 70s, Basilosaurus occupied a case in the fossil mammal exhibit in Hall 5. Photo courtesy of the Smithsonian Institution Archives.

In 1931, the Basilosaurus was upstaged by a new centerpiece: the mounted Diplodocus that took Charles Gilmore and his team more than a decade to assemble. The Diplodocus took the front-and-center position (where it remained until 2014), while the Basilosaurus was relocated to the south side of the hall. The Great Depression and World War II ensured that the east wing exhibits remained largely unchanged for nearly three decades after that, but the space was eventually renovated in the early 1960s as part of a Smithsonian-wide modernization campaign. In its new incarnation, the east wing’s open spaces were carved into smaller galleries dedicated to different groups of ancient life. With the central Hall 2 occupied by dinosaurs and fossil reptiles, the Basilosaurus joined the other Cenozoic mammals in Hall 5. This gallery became “Life in the Ancient Seas” in 1989, but the Basilosaurus remained in place.

The Basilosaurus was in the Ancient Seas gallery from 1989 to 2008.

For the Ancient Seas gallery, Basilosaurus was remounted with an arched tail. Photo by Chip Clark.

Life in the Ancient Seas was a very different setting for the Basilosaurus than the Hall of Extinct Monsters, reflecting the significant changes in museum interpretation that occurred during the 20th century. The historic exhibit showcased the breadth of the museum’s fossil collection in a fairly neutral environment. Interpretation was minimal, and generally intended for a scholarly audience. In contrast, Life in the Ancient Seas was an immersive educational experience (no pun intended). The Basilosaurus and other marine mammal skeletons were posed over a papier-mâché ocean bottom, while a blue and turquoise color palate and even shimmering lights contributed to the illusion of traveling through an underwater world. Combined with text panels written with a jovial, inviting tone, the net effect was an exhibit pitched to a general audience at home with multimedia.

The historic Basilosaurus, remounted for display in the Ocean Hall. Photo by the author.

The Basilosaurus was moved once more in 2008, when it was incorporated in the enormous new Ocean Hall. In its 5th position in a little over a century, the skeleton now hangs from the ceiling as part of an exhibit on whale evolution. Moving the historic skeleton was not an easy task, and took about six months of work. NMNH staff collaborated with Research Casting International to disassemble the skeleton, stabilize and conserve each bone, and finally remount the Basilosaurus on a new armature. In the new mount, each bone rests in a custom cradle with felt padding, to prevent vibration damage caused by the crowds passing beneath it. Smithsonian paleontologists also reunited the whale with its hind legs, which Schuchert found alongside the articulated vertebral column in Alabama but were, until recently, thought to belong to a bird.

This latest setting for Basilosaurus is a happy medium between museums past and present. The historic gallery occupied by the Ocean Hall has been restored to its original neoclassical glory, and much like the original Hall of Extinct Monsters visitors have clear sight lines across the space. Rather than being led on rails through a scripted exhibit experience, visitors can move freely through the gallery, bouncing among the objects they find compelling. At the same time, however, the Basilosaurus is explicitly contextualized as an example of the transformative power of evolution. Presented alongside cast skeletons of Maiacetus and Dorudon, this display makes whales’ evolutionary link to terrestrial mammals crystal clear.

This post was last updated on 1/8/2018.

References

Gilmore, C.W. (1941). A History of the Division of Vertebrate Paleontology in the United States National Museum. Proceedings of the United States National Museum No. 90.

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

Meet Basilosaurus, an Ancient Whale (2008). Smithsonian Institution. http://www.mnh.si.edu/exhibits/ocean_hall/meet_basilosaurus.html

The Last American Dinosaurs Has Arrived!

Hatcher the Triceratops greets visitors at the entrance to The Last American Dinosaurs.

Dinosaurs are once again on display at the National Museum of Natural History. Opening just in time for Thanksgiving weekend, “The Last American Dinosaurs” provides a much-needed dose of paleontology while the main fossil hall is being renovated. I was fortunate enough to take part in a preview tour for social media users – you can check out the storified version, or read on for photos and my initial thoughts on the new exhibit.

Stan the T. rex is sure to be a crowd-pleaser.

A Triceratops growth series reveals how much we’ve learned about the lives of dinosaurs over the last 25 years.

As promised, there are plenty of dinosaurs on view. Specifically, these are the dinosaurs of Maastrichtian North America, the last of these animals to grace this continent before the extinction event 66 million years ago. In addition to the mounted skeletons of Triceratops and Tyrannosaurus discussed in the previous post, be on the lookout for a hatchling and juvenile Triceratops, an Edmontosaurus, and bits and pieces from dromaeosaurs and pachycephalosaurs.

However, the dinosaurs are just the tip of the iceberg. As lead curator Hans-Dieter Sues explained within the first few minutes of the tour, the central message of this exhibit is that dinosaurs were only one part of a complex ecosystem. To that end, the dinosaurs of The Last American Dinosaurs are outnumbered by a menagerie of of reptiles, mammals, invertebrates, and plants that shared their world, most of which are on display for the first time. These specimens come from a variety of sources. Some, including turtles and fossil leaves, were collected by NMNH paleontologists in North Dakota specifically for this exhibit. Others, like the lizard Polyglyphanodon, have been in the museum’s collection since the 1930s but have never before been put on display. I also spotted a few casts sourced from Triebold Paleontology, including the mammal Didelphodon and the alligator-like Stangerochampsa.

This Polyglyphanodon was collected by Charles Gilmore in the 1930s.

Stangerochampsa and Champsosaurus are examples of animals that survived the K/T extinction.

Much like the Human Origins exhibit, The Last American Dinosaurs incorporates the faces of Smithsonian researchers and staff throughout the displays. There are large photos showing the museum’s scientists at work in the field, and the popular windowed FossiLab has found a new home in this exhibit. In addition, a large area is deservedly devoted to scientific illustrator Mary Parrish, chronicling the methods she uses to turn fossil data into gorgeously detailed renderings of prehistoric animals and environments. Videos of Parrish and others at work can be seen here.

I’m definitely a fan of this personalized approach to science communication. In-house scientists are museums’ most important and unique resources, and placing them front-and-center reminds visitors that science is done by real and diverse people, not caricatures in lab coats. A human face goes a long way toward making the process of doing science relateable to visitors.

Handwritten labels on these fresh from the field fossils provide a personal touch.

The phenomenon of extinction is another important theme in The Last American Dinosaurs. The exhibit details how an asteroid impact combined with several other factors to radically alter the environment worldwide, causing 70% of species to die out (fun fact: ambient temperatures in North America directly after the impact were comparable to the inside of a brick pizza oven). However, the exhibit goes on to make direct comparisons between the K/Pg extinction event and the anthropogenic extinctions of today. Habitat destruction, introduction of invasive species, and climate change caused by burning fossil fuels are instigators of environmental upheaval as powerful as any space rock.

This moa and dodo remind visitors that extinction isn’t limited to the distant past.

In this way, The Last American Dinosaurs is a warm-up for the key messages of the new fossil hall. The overarching theme of the planned exhibit is that “Earth’s distant past is connected to the present and shapes our future.” It will showcase how living things and their environments are interdependent, and change over time. Crucially, it will also demonstrate how our understanding of how life has changed over time is important for understanding and mitigating our impact on present-day ecosystems. The Last American Dinosaurs is evidently a testing ground for how these ideas will resonate with audiences.

Historic models of Agathaumas and Triceratops by Charles Knight and Charles Gilmore.

In designing modern paleontology exhibits, museum workers have tried many approaches to squelch the idea of the dinosaur pageant show and instead convey how the science of paleontology is relevant to our understanding of the world around us. Back in 1995, the American Museum of Natural History tried a cladistic arrangement with a focus on biodiversity. More recently, the Field Museum used the process of evolution to frame the history of life on Earth. While there are certainly overlaps with what has come before, the “modern implications of environmental change over deep time” approach under development at NMNH is fairly novel, and also quite timely. Some of the displays in The Last American Dinosaurs hit pretty close to home, and I’m eager to find out how visitors respond.

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Filed under dinosaurs, exhibits, fossil mounts, mammals, marginocephalians, museums, NMNH, ornithopods, paleoart, reptiles, reviews, science communication, theropods

Tagged as dinosaurs, exhibits, fossil mounts, NMNH, paleoart, science communication, Smithsonian, Triceratops, Tyrannosaurus

November 14, 2014 · 1:56 pm

Hatcher, Stan, and the Changing Identities of Fossil Mounts

Hatcher the Triceratops and Stan the T. rex in the NMNH fossil hall, early 2014. Photo by the author.

Although the east wing fossil halls are closed for renovation until 2019, the National Museum of Natural History will not be without a dinosaur display for much longer. An interim exhibit entitled “The Last American Dinosaurs” will open later this month, occupying the space that formally held the “Written in Bone” exhibition. The Last American Dinosaurs will cover a small but important slice of the age of dinosaurs: the final ecosystem to grace North America before the extinction event 66 million years ago. While the new exhibit will feature several show-stealing dinosaurs, the main message is that these animals lived within a complete and complex ecosystem, just like the animals of today. The exhibit will also cover the phenomenon of extinction, and how massive environmental change (whether caused by a giant space rock or by human activity) can drastically alter the course of life on Earth.

What I’d like to discuss in this post are the two dinosaurian centerpieces of the exhibit: Hatcher the Triceratops and Stan the Tyrannosaurus. Both mounts stood in the classic fossil hall for years, and I’ve already written extensively about each of them. Nevertheless, these two dinosaurs nicely encapsulate the history of mounted fossil skeletons, as well as the changing face of museum paleontology. As the ambassadors to the Smithsonian’s dinosaur collection for the next five years, I think it’s worth revisiting their origin stories.

The First Triceratops

This Triceratops stood in the NMNH fossil hall for nearly 90 years. Photo courtesy of the Smithsonian Institution Archives.

The Smithsonian Triceratops hails from what we might call the golden age of museum paleontology. Mounted dinosaur skeletons were an integral part of the rise of large urban natural history museums at the turn of the 20^th century. The opening of the American western frontier revealed an unprecedented treasure trove of fossils, far greater than what was previously known in Europe. As a result, paleontology became one of the first realms of science in which Americans were leaders, and patriotism was a significant factor in the growing public enthusiasm for extinct monsters. Wealthy benefactors of recently formed institutions like the American Museum of Natural History and the Field Columbian Museum envisioned the mounted skeletons of dinosaurs as an opportunity to increase attendance and public interest, and they provided ample funding to find fossils for display. These efforts were not wasted, as the golden age fossil mounts have been enjoyed for generations…and most are still on display today.

It’s easy to get caught up in the romanticism of this era of discovery and exposition. Golden age fossil mounts were forged into being entirely in-house. At a given museum, the same small group of staff was frequently responsible for finding, preparing, describing, naming and mounting a new dinosaur. As such, fossil mounts were typically exclusives to particular museums, and they garnered significant amounts of institutional and regional pride. New York had “Brontosaurus” and Tyrannosaurus. Pittsburgh had Diplodocus. And for more than 20 years, Washington, DC had the world’s only mounted Triceratops.

A spread in the June 11, 1905 Sunday Star profiled the Smithsonian Triceratops. Image courtesy of the Smithsonian Institution Archives.

Built in 1905 by Charles Gilmore and Norman Boss, the Smithsonian Triceratops has been a Washington, DC attraction for longer than the Lincoln Memorial. Like most turn of the century dinosaur mounts, it is not a single specimen but a composite of several individuals. The fossils were recovered from Wyoming by the prolific fossil hunter John Bell Hatcher, working in the employ of O.C. Marsh and the United States Geological Survey*. USNM 4842, the most complete partial skeleton available, provided the torso and pelvis, while the remains of at least six other Triceratops filled in the rest of the mount.

*Incidentally, this means the Triceratops doesn’t quite fit the story I outlined above. It was not discovered or named by Smithsonian scientists – instead, the Smithsonian inherited the fossils Marsh collected for the federal government when he was through with them.

Even though it was a slightly disproportionate chimera, for experts and laypeople alike the Smithsonian Triceratops mount was Triceratops. Virtually every illustration of the animal for decades after the mount’s debut dutifully copied its every eccentricity, including the slightly undersized head and excessively sprawled forelimbs. If you can strain your eyes to read Sunday Star article above, it’s also interesting to see how the mount was presented to the public. Even in an era when museum displays were unapologetically created by experts for experts, the Triceratops is repeatedly likened to a fantastical monster. Although the creation of the mount was an important anatomical exercise for the small community of professional paleontologists, it seems that for most visitors a display like this primarily served as whimsical entertainment.

Hatcher was moved to his new home on the second floor at the beginning of the summer. Photo by the author.

After a brief stint in the original United States National Museum (now called the Arts and Industries Building), Gilmore and Boss’s Triceratops was transferred the east wing of the present-day NMNH in 1911. It remained there for 90 years, until the aging and deteriorating fossils were finally disassembled and retired to the collections. In their place, Smithsonian staff created an updated replica skeleton, called “Hatcher”, from digital scans of the original bones. This version is the Triceratops that will be on display in The Last American Dinosaurs.

A Prefab Tyrannosaurus?

Stan the T. rex, as seen in the classic NMNH fossil hall. Photo by Chip Clark.

Since 2000, Hatcher the Triceratops was in a permanent face-off with another replica mount, Stan the Tyrannosaurus. Unlike Hatcher, Stan is not based on fossils in the Smithsonian collection. This T. rex cast was purchased from the Black Hills Institute, a private company that produces and sells replica fossil skeletons (as well as original specimens, which is another issue entirely). Discovered by avocational fossil hunter Stan Sacrison in 1987, Stan the dinosaur was excavated and is now owned by BHI. Since 1995, BHI has sold dozens of Stan replicas to museums and other venues. The Smithsonian acquired its version in 1999, in part because of visitor demand for the world’s most famous dinosaur, but also apparently as a consolation prize for missing out on Sue.

Clearly, much has changed in the way museums source their dinosaurs. Rather than creating fossil mounts on-site, museums frequently contract out the production to exhibit fabrication companies like Research Casting International, Gaston Design, and the aforementioned Black Hills Institute. These companies can construct mounts using fossils or casts from a particular museum’s collection, but they also offer catalogs of made-to-order skeletons. Thanks to these exhibit companies, more or less identical copies of certain dinosaurs are now on display all over the world. In Stan’s case, the Smithsonian version has a twin just seven miles north at the Discovery Communications building in Silver Spring.

Stan can be set up in a under an hour. This version was recently displayed at Farmington Museum.

Stan replicas can be set up in a under an hour. This version was recently displayed at New Mexico’s Farmington Museum. Source

An argument could be made that this degree of replication lessens the impact and cultural value of dinosaur displays. How much allure does a mount have when identical versions can be seen at dozens of other locations, including corporate offices and amusement parks? I would counter that this is a small price to pay when we consider the substantial educational benefits of this unprecedented availability of dinosaur skeletons. Widespread casts like Stan give people all over the world the opportunity to see a T. rex in person, an experience that was until recently limited to those with the means to travel to a handful of large cities. Typically priced in the tens of thousands of dollars, dinosaur casts certainly aren’t cheap, but they are still within the means of many small to mid-sized local museums.

Furthermore, these casts are hardly rolling off of assembly lines. They are exact replicas of real fossils, and require a tremendous amount of experience and skill to produce. Mounts are manufactured as needed, and are customized to meet the needs of the specific museum. Meanwhile, museums still employ scientists who collect new fossils for their collections. The difference is that these collecting trips usually seek to answer specific research questions, rather than going after only the biggest and most impressive display specimens. Finally, museums definitely haven’t outsourced exhibit production entirely. All summer at NMNH, in-house preparators have been working in collaboration with contractors from Research Casting International to dismantle the historic fossil exhibits in preparation for the upcoming renovation.

Reassembling Stan upstairs. Photo by Abby Telfer.

Reassembling Stan for The Last American Dinosaurs. Photo by Abby Telfer.

There’s one more change for the better in modern paleontology exhibits. When the Smithsonian Triceratops was first introduced to the world in 1905, natural history displays tended to focus on the breadth of collections. Curators composed exhibits with other experts in mind, and the non-scholars that actually made up the majority of museum visitors were not directly catered to. Without any context to work with, fossil mounts were little more than toothy spectacles for most visitors. Today, museum staff create exhibits that tell stories. The Last American Dinosaurs has been explicitly designed to contextualize the dinosaurs – to show how they fit into the history of life on Earth, and why their world is meaningful today. How successful will this be? I’ll report back after the exhibit opens on November 25th.

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Filed under dinosaurs, exhibits, fossil mounts, history of science, marginocephalians, museums, NMNH, reptiles, theropods

Tagged as dinosaurs, exhibits, fossil mounts, history of science, museums, NMNH, paleontology, Triceratops, Tyrannosaurus

October 26, 2014 · 7:07 pm

Exhibit Review: Kenosha Dinosaur Museum

Stan the Tyrannosaurus with a modern eagle. Photo by the author.

Last week, I had a chance to visit the Dinosaur Discovery Museum in Kenosha, Wisconsin. I had no idea this place existed until recently, but it’s a short drive north from the Chicago area, and has apparently been open since 2006. The Museum is a joint venture between the municipally funded Kenosha Public Museum system and Carthage College, and is housed in a lovely 1930s post office (on the National Register of Historic Places). As I understand it, the Dinosaur Discovery Museum was initially imagined as a space to host the undergraduate paleontology program at the College, which is led by Dr. Thomas Carr. While the Museum does include a working fossil prep lab and displays of recent finds from Carr’s field expeditions in Montana and South Dakota, the primary draw for most visitors is the permanent exhibit hall. Although less than 100 feet across, this space is packed with more theropod mounts than I have ever seen in one place.

Nary an ornithiscian in sight. Photo by the author.

Naturally, the theme of this theropod-centric exhibit is bird evolution. Circling the central pedestal counter-clockwise, visitors can see the radiation of theropods from primitive forms like Herrerasaurus to larger ceratosaurs and tetanurans and finally to increasingly bird-like coelurosaurs. The Dinosaur Discovery Museum must have gotten a very generous initial donation, because they seem to have bought out virtually the entire catalog of casts from both the Black Hills Institute and Triebold Paleontology.

A squatting Hererrasaurus is one of many unusually posed mounts at the Dinosaur Discovery Museum. Photo by the author.

Many of the casts were familiar to me, including the ubiquitous Stan, the Acrocanthosaurus from the North Carolina Museum of Natural Sciences, and the Anzu from the Carnegie Museum of Natural History. Nevertheless, it’s extremely cool to see such a complete range of theropod diversity in one place. I could directly compare any bone from a given mount to the same bone on any other, or even to the helpful selection of modern bird skeletons. The only thing that would make this exhibit more complete would be the inclusion of growth series from the taxa for which this is known, like Tyrannosaurus and Allosaurus. And for the record, jaded paleophiles, T. rex looks really impressive alongside this menagerie. Overrated, my eye.

Torvosaurus scratches its jaw. Photo by the author.

Unlike some exhibits, the Dinosaur Discovery Museum does not shy away from the fact that all the skeletons on display are casts. Most of the mounts are very obviously painted in two colors, showing precisely which bones are based on real finds and which are sculpted reconstructions. Unfortunately, a handful of mounts inexplicably lack this information, which could confuse some visitors. One helpful side effect of displaying casts is that the dinosaurs can be placed in a variety of life-like poses. These theropods are not all staring straight ahead with mouths agape – instead, we are treated to displays like the Torvosaurus above, which is scratching its head with its foot.

Signs like this accompany each dinosaur. Photo by the author.

The signage is of similarly high quality. Each dinosaur is accompanied by an attractive panel that provides expected information like the animal’s diet and time period, as well as a very helpful section identifying the quarry where the fossils were found and in most cases, the repository housing the original specimen. Additional signs on the walls cover the origin and extinction of dinosaurs, as well as the many lines of evidence that birds are surviving dinosaurs. Although they look a bit wordy at a distance, these signs are quite well-written for inclined to peruse them.

Acrocanthosaurus and an Allosaurus at rest. Photo by the author.

Also of note is a children’s room on the lower level, featuring (sigh) a sandbox dig and some very helpful and enthusiastic volunteers. Indeed, children’s activities appear to be the Dinosaur Discovery Museum’s strong suit. A look at their website reveals that kid’s programs are scheduled every weekend, and special events like dinosaur ornament making and flashlight tours occur throughout the year.

Clearly, I was impressed by my visit to the Dinosaur Discovery Museum. It’s wonderful that an educational opportunity like this exists in a semi-rural community, something that would have been unheard of not so long ago (did I mention it’s free?). What’s more, the exhibit hall is a great resource for specialists interested in comparing a variety of theropods first-hand. If you ever find yourself in the area, this little museum is definitely worth a visit.

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Filed under dinosaurs, education, exhibits, fossil mounts, museums, reptiles, reviews, science communication, theropods

Tagged as Dinosaur Discovery Museum, dinosaurs, exhibit reviews, fossil mounts, museums

August 25, 2014 · 4:30 pm

Hello new followers!

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

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.

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.

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 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!