March 24, 2013 · 4:00 pm

Fossil mounts in the museum environment

Sue and Stan reconstructions from Scott Hartman's DeviantArt page.

Sue and Stan reconstructions from Scott Hartman’s DeviantArt page.

Scott Hartman posted the above image to his DeviantArt page the other day, comparing the Tyrannosaurus specimens Sue and Stan side by side. For those unfamiliar, Hartman is known for his rigorously measured skeletal diagrams of dinosaurs (and sometimes other animals) that are crucial references for many artists and paleontologists. I’m always impressed by Hartman’s work, but this new comparative image really floored me. I knew that Sue is the largest and most complete rex yet found, but I had never properly appreciated what a monster she is. I’ve seen the mounted Sue skeleton at the Field Museum several times, and I’ve seen at least four casts of Stan in various locations, but I never realized what a significant size disparity exists between the two.

Tyrannosaurus Sue at the Field Museum of Natural History.

Tyrannosaurus Sue at the Field Museum of Natural History.

Tyrannosaurus Stan at the National Museum of Natural History.

Tyrannosaurus Stan at the National Museum of Natural History.

It’s not a groundbreaking discovery by any means, but I’m struck by how important the museum environment is when exhibiting a mounted skeleton. I mentioned yesterday that exhibits are never neutral, and this is a particularly clear example. Sue is exhibited in the gigantic central hall of the Field Museum, and in this open, grandiose environment, her size is actually deemphasized. By comparison, the presence of the Stan mount at the National Museum of Natural History was not anticipated during the 1981 renovation of the dinosaur hall (it was added in 2001, I believe) and is sort of crammed into a corner. In the cramped space, Stan looks pretty big, and it’s little wonder I had never appreciated the marked difference in size between the two mounts.

The takeaway, I guess, is that it would do us well to pay careful attention to the design choices (or constraints) in a museum exhibit. We’d like to think that a rare and important specimen like a Tyrannosaurus skeleton speaks for itself, but visitor impressions of even these fossils are shaped by the context they are placed in.

Leave a comment

Filed under dinosaurs, fossil mounts, museums, NMNH, paleoart

Tagged as , , , ,

March 23, 2013 · 7:49 pm

Drama and natural history

While running errands this morning a thought came to me: a natural history exhibit in a museum is a lot like a stage performance*. When watching a play, the viewer knows she is seeing a performance, but it willing to suspend disbelief so long as the fantasy is well-created. To varying degrees, most modern natural history exhibits engage in the same theatrical relationship with their audiences. Exhibits re-create reality within the museum environment, and visitors accept the performance as truth.

*Actually, I thought “movie” first, but theater is a better analogy because the actors are real and present.

CMNH zebra diorama. Source: amyboemig on flickr.

A rather poignant picture of the CMNH zebra diorama. Source: amyboemig on flickr.

Habitat dioramas featuring taxidermied animals are the most obvious example. Dioramas like the lovely east African savannah scene at the Carnegie Museum of Natural History pictured above are exactingly detailed microcosms modeled after actual environments. The backdrops are typically  based on photographs of real locations. The teams that collected the animal skins would also take samples of leaves and even molds of tree bark, in order to exhibit the ecosystem in toto. And of course, the mannequins on which the animal skins are mounted were sculpted by artists with a strong foundation in anatomical science. And yet, the diorama is clearly not real. Visitors know that they are not looking at an actual game reserve that has been somehow frozen in time. Many viewers might mistake the animals as being “stuffed” (they are in fact sculptures with tanned skins fitted onto them), but  they still recognize some element of artifice.  The animals clearly didn’t end up in the glass-enclosed box on their own accord. And yet, visitors accept the illusion, because they keep coming to museums to learn about the world around us.

The same holds true for most other displays. These dioramas at the New York State Museum are not literally historic Iroquois villages shrunk down to 1/20 scale. The Tyrannosaurus and Triceratops pictured below are not really fighting, nor did they die in a death struggle. Even the Apple Store-eque NMNH Hall of Mammals recreates natural behaviors against a sterile backdrop. Unless the museum is displaying completely decontextualized specimens lying prone on a shelf, there is some degree of theatricality in the exhibit.

Tyrannosaurus and Triceratops at the Children’s Museum of Indianapolis. Source.

The theater analogy begins to go astray, however, when we consider that the performances in natural history exhibits are informed by reality. For the most part, exhibit designers do not place specimens in completely fictitious scenarios; the theatrical element serves to illustrate something real. Perhaps exhibits are more akin to a movie “based on a true story.” But like those movies, there is an undeniable selectivity in how museum workers tell their stories.  Why are the zebra in the CMNH diorama chilling amicably with wildebeest? That is certainly something that real zebra have been known to do, but zebra have also been known to drown lions, trample foals and chew on the cars of obnoxious tourists. For that matter, why does this diorama not include any sign of human pastoralists, who have lived in the same environment as these animals for thousands of years?

Exhibits have human authorship, just like any other document. The manner in which any specimen or object is displayed is inherently subjective, and there will always be emphasis and omissions, intentional or otherwise, that change the way the exhibit is interpreted. Before you misjudge me, dear reader, this is not an argument that there is no objective reality. I wouldn’t even say that it is impossible to understand and perceive objective reality. Scientists do it all the time. But when it comes time to communicate that information, we are creating something new, and choosing what we incorporate and how we express it. Getting back to my original point, we’re putting on a representational show. And that means that what we’re creating only works as long as our audience is willing to participate in the performance.

 

Leave a comment

Filed under anthropology, fossil mounts, mammals, museums, science communication

Tagged as , , , ,

March 18, 2013 · 4:45 pm

A Visit to the Academy of Natural Sciences

I spent yesterday in Philadelphia, my first visit in at least 10 years, and of course made a point of visiting the Academy of Natural Sciences. Founded in 1812, the Academy is the oldest natural science research institution and museum in North America, established “for the encouragement and cultivation of the sciences, and the advancement of useful learning.” Initially formed as a hub for research on the American frontier, the Academy has sponsored scientific expeditions across the world and has amassed a collection of 17 million specimens that is still actively used 200 years after its founding.

In 1868, the Academy museum made a landmark contribution to paleontology by hosting the first mounted dinosaur skeleton ever constructed. The mount, the work of paleontologist Joseph Leidy and sculptor Benjamin Waterhouse Hawkins, depicted Hadrosaurus foulki, the first dinosaur discovered in North America and at the time the most complete dinosaur ever found. With only two limbs, a section of the spinal column and some other odds and ends to work with, Hawkins invented many of the mounting techniques that are still in use today. For instance, Hawkins created mirrored duplicates of the left limb bones for use on the animal’s right side, and reconstructed best-guess stand-ins for the skull, scapulae and most of the vertebrae using extant animals as reference. By modern standards, the Leidy-Hawkins Hadrosaurus mount wasn’t especially accurate (the sculpted scapulae and vertebrae resemble those of a mammal, not a reptile; the skull, based on that of an iguana, turned out to be completely off the mark; the fully upright, kangaroo-like posture is now known to be anatomically implausible), but it nevertheless presented the first-ever opportunity to stand in the presence of a dinosaur. Extinct animals were already known to the public, and some had even been mounted, but the Hadrosaurus was so bizarre,  so utterly unlike anything alive today, that it really opened people’s eyes to the unexplored depths of the Earth’s primordial history.

Original 1868 Hadrosaurus mount.

Original 1868 Hadrosaurus mount.

The Hadrosaurus display caused public visitation to skyrocket, prompting the Academy to relocate in 1876 to a larger building in central Philadelphia, where it remains today. I haven’t been able to find any photographs or detailed information about it, but for much of the 20th century the Academy had a fossil exhibit with a Corythosaurus mount as its centerpiece. This was replaced in 1986 with an expanded “Discovering Dinosaurs” exhibit, which apparently was among the first to showcase the discoveries of the dinosaur renaissance. This exhibit has just about zero web presence, as well (seriously, any help tracking down details about it would be greatly appreciated). The current version of the Dinosaur Hall opened in 1998, and is what I will discuss below.

This cast of the AMNH Tyrannosaurus is the centerpiece of the Dinosaur gallery. Source: Wikipedia Commons.

What’s Cool

Although crammed into a fairly small space, the Academy’s two-level Dinosaur Hall is packed with mounts of North American fossil reptiles, including Tyrannosaurus, Chasmosaurus, Deinonychus, Tylosaurus, Pachycephalosaurus and many more. Compared to the sterile and coldly scientific displays at larger museums like the American Museum of Natural History, the Academy’s exhibit designers clearly put an emphasis on accessibility, particularly for younger visitors. Signs are attractive, colorful and use simple language, but do not sacrifice scientific accuracy. Although “Do Not Touch” notices abound, guardrails are low and allow visitors to view the mounts up close. Even the fossil prep lab, a staple in paleontology exhibits, is not behind glass but is separated from visitors by a low wall, allowing guests to converse freely with the preparators if they so choose (This might not be so fun for the preparators; I’ve worked in a couple of these labs and I’ll be the first to admit that our conversations are not always for public ears).

The Academy’s Dinosaur Hall is also filled with interactive activities. I question the educational value of a green-screen that places visitors into a scene with dinosaurs running around (the last thing we need is to encourage more people to think humans and dinosaurs coexisted), but many of the other interactives are quite inspired. In one corner, children are encouraged to climb inside a Tyrannosaurus skull cast to find evidence for its diet and lifestyle. Crouching between its jaws, kids find partially-erupted teeth, evidence that the predator broke and regrew teeth throughout its life. My favorite interactive, however, featured parallel rows of theropod and crocodile footprints on the floor. Visitors were directed to walk down each trackway, comparing how it felt different to move with an upright or sprawling gait. At the end, a sign explained that it’s harder, and less energy efficient, to move like a crocodile. I loved this activity because it was simple (just images on the floor, no technology required) and yet conveyed a clear explanation of biomechanics. Visitors use their own bodies to reach the conclusion, finding the answer in a tactile and experiential way that is more memorable than just being told that a sprawling posture is inefficient.

Overall, the Dinosaur Hall is a great overview of dinosaur science. It focuses on the biology of dinosaurs, emphasizing their similarity to animals we know today, and how scientists can draw conclusions about past life by studying the modern world. This content is communicated in a way that is clear and engaging for visitors of all ages, making this exhibit a good example of the old adage that all good science can be explained in simple terms. When I visited, there were a couple children using the open exhibits like a playground, but for the most part I think this highly accessible dinosaur exhibit is quite successful.

What’s Not So Cool

The Academy’s Dinosaur Hall is 15 years old, and is in some places showing its age. Some of the exhibit content is not entirely up-to-date; for instance, a display on the relationship between birds and dinosaurs leaves the question completely open ended. I also saw at least two invalid names, “Majungatholus” and “Ultrasauros”, used on labels. Probably more obvious to most visitors is the general wear and tear visible in certain parts of the exhibit. Some labels, particularly those facing large windows, are badly faded. The Elasmosaurus mount was moved from the Dinosaur Hall proper to the entrance lobby at some point, but Elasmosaurus signage, now labeling an empty space, is still in place in the exhibit. I got the impression that the Academy, like much of Philadelphia, is hurting for funding.

Corythosaurus and Chasmosaurus mounts. Source: TravelMuse.

The story of Leidy’s Hadrosaurus appears in several places throughout the museum. Casts of the original fossil material are displayed over a silhouette of the dinosaur toward the back of the Dinosaur Hall. Elsewhere , there is a new full casted mount of Hadrosaurus (signs explain that it is filled in with Maiasaura material), and the original tibia is displayed as part of a rather cool 200th Anniversary special exhibit. At the time, I wished that these displays were consolidated in one place, since the Hadrosaurus story is an important chapter in the history of science and of museums that can be seen exclusively at the Academy. I later found out that in 2008, the Academy had a major temporary exhibit commemorating the 150th anniversary of the original Hadrosaurus mount, which featured, among other things, a recreation of the victorian-era exhibit and the workshop of Benjamin Waterhouse Hawkins (great videos and interviews about the exhibit here). I wish I had been able to see that, because it blends the scientific, cultural and historic value of fossil mounts in a way that only this museum can.

The sadly closed Hadrosaurus Anniversary exhibit. Note Hawkins’ original sculpted head on the red pillow. Source: The Art Blog.

The current centerpiece of the Dinosaur Hall is a cast of the AMNH Tyrannosaurus. It’s neat, but I imagine most visitors would be more enthused to see the real one just a couple hours down the road. Indeed, most of the dinosaurs on display at the Academy are casts from other institutions. I have no problem with displaying casts, but I can’t help but feel that this generalized dinosaur exhibit is underselling the Academy’s own fossil collections, not to mention its contributions to paleontology. Should the Academy renovate this space again, I’d love to see the institutions’ unique history play a more prominent role, as well as the work that Academy-affiliated researchers are doing today.

Leave a comment

Filed under collections, dinosaurs, exhibits, fossil mounts, history of science, museums, ornithopods, reptiles, reviews, science communication

Tagged as , , , , , ,

January 31, 2013 · 2:43 pm

Scientific uses for fossil mounts

I have a question for the paleontological community. I know this blog doesn’t get anywhere near the traffic to expect many answers, if any, but I’m going to ask it anyway.

How do fossil mounts factor into your research? What information can be gained from an assembled and articulated vertebrate skeleton that cannot be determined (or is more difficult to determine) from the study of individual bones? Mounts did have a role in research historically: for instance, Gilmore used the process of creating the Triceratops, Camptosaurus and Diplodocus mounts for the United States National Museum to correct anatomical errors and assumptions previously published by Marsh. But are we still learning from the process of physically assembling skeletons (digital models don’t count)?

I ask because my immediate assumption is that mounts do not benefit research. Fossil mounts clearly have (admittedly difficult to quantify) educational value. They are spectacular, awe-inspiring displays with a physical presence that no book, film or shoddy cable documentary could hope to achieve. For many, including myself, fossil mounts were a first encounter with science in general, inspiring me to ask questions about the natural world and seek ways to answer them. But if we focus entirely on the process of studying and learning from fossils, do mounts have any value?

There is no shortage of reasons why mounts utilizing original fossils are problematic for researchers. Mounted fossils, which are often all-important holotypes, are difficult for researchers to access, and certain parts of the skeleton, like the back of the skull or the vertebral bodies, cannot be reached at all. The mounting process, while better than it was a century ago,  is invasive, destructive and sometimes irreversible.  Mounted fossils in public spaces inevitably suffer damage from fluctuating temperature and humidity (such as pyrite disease), uneven weight distribution and vibration from passing crowds. Many historic mounts used plaster or shellac to seal bones together or to reconstruct broken pieces, which is effectively impossible to remove without damaging the fossils. In the case of the Peabody Museum Apatosaurus, modern researchers do not know how much of certain bones are real and how much was reconstructed.

There is a long, worthwhile discussion to be had on whether the needs of research or the needs of education are more important in this scenario (David Hone and Heinrich Mallison make a case for each side on their respective blogs). But before I get to that point, I’d like to sort out if the distinction is as clear cut as “mounts good for education, mounts bad for research.” Any comments or experience on the matter would be very much appreciated!

8 Comments

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

January 8, 2013 · 8:28 pm

Extinct Monsters: Murals and Dioramas

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

Fossils are the hard evidence behind paleontology. They tell us not only that prehistoric organisms existed, but hold clues as to how they lived and behaved. However, it is only through  artwork that extinct animals and ecosystems can be brought back to life. Since Benjamin Waterhouse Hawkins built the first life-sized dinosaur sculptures in 1842, skilled artists have played a critical role in visualizing the results of paleontological research and making that information available to a wider audience.

At the National Museum of Natural History, spectacular works of art have always appeared alongside displays of original fossils, firing up the viewer’s imagination and inviting them to visualize the world of prehistory. Although many of these pieces are now scientifically dated, they were on the cutting edge in their time. These artworks remain exquisite works of craftsmanship, invaluable for their decades of contribution to science education.

The Life-Sized Models

The charmingly ugly Stegosaurus is one of the oldest fixtures of the Smithsonian fossil exhibits. F.A.L. Richardson created this model for the the Smithsonian’s exhibition at the St. Louis, Missouri World’s Fair in 1904. Made from papier mâché with a foam skin, the Stegosaurus was based on small sculpture produced by Charles Gilmore. With its sagging belly, sprawling forelimbs, and head held well below the horizontal plane, this Stegosaurus is typical of reconstructions from the early to mid 20th century.

As legend had it, the paper used to fabricate the Stegosaurus was ground-up money from the National Treasury. The model had even earned the nickname “Mr. Moneybags” among some of the museum staff. Curator Emeritus Ray Rye got to the bottom of this in 1981. He contacted the Treasury to find out what was done with worn-out paper money at the turn of the century – apparently it was burned at a plant in Maryland. Nevertheless, at Rye’s request a group of historians from the Treasury took a sample of the Stegosaurus while the hall was closed for construction, and confirmed that it was made from regular paper.

This pudgy papier mache Stegosaurus has been a fixture at the Smithsonian since 1904.

This pudgy Stegosaurus has been a fixture at the Smithsonian since 1904. Photo courtesy of the Smithsonian Institution Archives.

When the Hall of Extinct Monsters opened in 1910, the Stegosaurus was given a spot of honor right in the center of the room. In 1913, a real Stegosaurus skeleton was placed alongside it. Both dinosaurs would remain in place until the exhibit was renovated in 1963. In the reconfigured and renamed Hall of Fossil Reptiles, the model Stegosaurus was relocated to a corner display.  Most recently, the 1981 renovation saw the Stegosaurus model moved to the south side of the gallery, protected by a low plexiglass barrier. This time, it was given a cycad replica for company, and a mural of lush Jurassic jungle behind it. The Stegosaurus remained in this position until the fossil halls closed in 2014.

quetzalcoatlusprogress

The NMNH exhibits team with their nearly-finished Quetzalcoatlus. Image from Thomson 1985.

quetzal2014

The Quetzalcoatlus survived a 2010 earthquake, although the plaster molding above it was damaged. Photo by the author.

The 1981 renovation also saw the introduction of a life-sized model of the pterosaur Quetzalcoatlus. Having been discovered in 1971, the largest flying animal that ever lived was big news at that time. In-house modelmakers spent two years on the project, first sculpting the animal in clay, then casting it in lightweight fiberglass with a steel armature. Paleontologist Nicholas Hotton served as the scientific consultant. Although he was dubious that pterosaurs had any sort of soft body covering, he okayed the use of deer fur to give the model believable texture. However, Hotton nixed the idea of placing a dangling fish in the mouth of the Quetzalcoatlus. Contemporary wisdom was that even giant pterosaurs were extremely light, weighing as little as 75 pounds, so even a 5-pound fish was thought to be enough to disrupt a Quetzalcoatlus in flight.

The Stegosaurus and Quetzalcoatlus both now reside at the Museum of the Earth in Ithaca, New York.

The Murals

The first dedicated prehistoric mammal exhibit at NMNH opened in the summer of 1961. Alongside the array of Cenozoic fossil mounts, the exhibit featured four brand new murals created by paleoartist Jay Matternes (he painted two more for the Ice Age hall several years later). Still active today, Matternes is a prolific artist of both modern and prehistoric wildlife. In addition to the NMNH murals, Matternes has contributed to exhibits at the American Museum of Natural History and the Cleveland Museum of Natural History, as well as numerous publications including National Geographic Magazine.

c.11

Matternes’ Oligocene mural as first exhibited in the 1960s. Photo courtesy of the Smithsonian Institution Archives.

Oligocene and early Miocene murals, as seen in the 1985-2014 iteration of the exhibit, Mammals in the Limelight. Photo by the author.

Each of the murals Matternes contributed to the exhibit depicts North America during an epoch of the Cenozoic, and is displayed behind corresponding fossil mounts. Most of the animals on display coincide with life reconstructions in the murals, so visitors can match the skeletons to images of how they may have looked in life. Matternes’ hyper-detailed style is particularly striking. The environments look nearly photo-real, and not too far removed from the world today. Likewise, the artist’s knowledge of anatomy plainly shows in the utterly lifelike appearances of the animals. I particularly like Matternes’ use of familiar color patterns on the relatives of modern taxa. The Pliocene and Pleistocene murals will be returning in 2019.

Cenozoic

The Cenozoic section of Kish’s 130-foot magnum opus. Source

The “Life in the Ancient Seas” exhibit debuted in 1990 with a monumental 130-foot mural by Eleanor Kish. From the explosion of invertebrate diversity in the Cambrian to the proliferation of aquatic mammals in the recent past, the mural spans 541 years of deep time. The project took Kish two years to complete and is, simply put, a masterpiece. Within the exhibit, this meticulously crafted image defines the space’s layout and color palate. It visually separates concepts and themes, and even directs visitor traffic with its strong leftward momentum.

The Dioramas

The dinosaur dioramas were one of my favorite parts of the old NMNH fossil halls. Norman Neal Deaton created three dioramas, representing North America during the Triassic, Jurassic, and Cretaceous. The Mesozoic dioramas were commissioned for the 1963 exhibit renovation, and were on display until 2014. Each 1″:1′ scale diorama is set into a recessed space in the wall and is protected by glass.  The scenes are populated by a menagerie of outdated but gorgeously detailed dinosaurs and contemporary reptiles, set among dense forests of ferns and craggy rock formations. The complexity of the dioramas allows viewers to get lost in them as their eye wanders from one static encounter to the next. I’ve been admiring these scenes since literally before I could talk and I still notice minute details I hadn’t seen before.

The diorama project began in 1963 and took four years to complete. The scenes were initially blocked out by Jay Matternes and Nicholas Hotton, the Curator of Vertebrate Paleontology at the time. Matternes and Hotton worked together on anatomical drawings for each of the animals to be reconstructed, and planned the basic layout of the dioramas. Deaton created the final dioramas at his studio in Newton, Iowa. Deaton had been previously employed at the Smithsonian as an exhibits specialist, but had left to found his own studio in the late 1950s, where he continued to work on projects for the Smithsonian as a contractor. In addition to the dinosaur dioramas, Deaton led the creation of the iconic Fénykövi elephant that stands in the NMNH rotunda today, and has created sculptures and dioramas for dozens of other museums. Deaton is still active today, and much of his 2-D and 3-D work can be seen at his website.

Deaton mailed these slides of his unpainted models to Hotton for approval. Photos courtesy of the Smithsonian Institution Archives.

Deaton mailed these slides of his unpainted models to Hotton for approval. Photos courtesy of the Smithsonian Institution Archives.

Deaton sculpted each of the animals in clay based on the drawings provided by Matternes and Hotton. Nearly every model went through a few incremental adjustments based on notes from Hotton, changing things like the bulk of the muscles or how visible the scapula or pelvis would be under the skin. The soft anatomy was based on modern reptiles, particularly crocodiles, although Deaton found that some of the animals had no obvious analogs. Once the clay models were approved, they were casted in rubber, then painted. Deaton also created the miniature worlds inhabited by the animals, including foliage, muddy riverbanks, and sheer cliffs. The backdrops, however, were painted by Matternes.

The completed dioramas represented the most up-to-date knowledge of the Mesozoic world at that time. Of course, our understanding of dinosaurs has been overhauled significantly since then. Compared to the active, fleet-footed, and often feathered dinosaurs we know today, the inhabitants of the NMNH dioramas at first look a bit ponderous and inert. Inaccuracies are easy to point out: the Ankylosaurus has a weird clubless armadillo tail, the torso of the Diplodocus is much too long, the Cretaceous diorama mixes Hell Creek and Belly River dinosaurs that were separated by at least 20 million years, and there are sprawly tail-draggers aplenty.

Cretaceous diorama by Norman Deaton. Source: flickr.

Cretaceous diorama by Norman Deaton. Photo by the author.

Triassic diorama

Triassic diorama by Norman Deaton. Source

Still, these issues are easy to overlook when one appreciates just how engaging these scenes are. Little details like footprints behind each animal and mud splattered on their feet fill the motionless dioramas with life and the possibility of more adventures in the imagination of the viewer. And several of the models are surprisingly energetic for 60’s dinosaurs. The Ceratosaurus face-biting the Camptosaurus (above) is full of energy, and the Elphrosaurus  is running full-tilt with its tail in the air (and even has propatagia for some reason).

Many of the works of art in the NMNH fossil halls are no longer appropriate as literal representations of prehistoric animals. But that does not mean they are irrelevant relics of mid-century science. Each model and painting is a stunning example of artistry, and more to the point, every inaccuracy is an opportunity to start up a conversation about what we know about prehistory and how we know it. These pieces are time capsules in the history of science, representing different eras of understanding and the researchers that took part in them. I, for one, would hate to see them forgotten.

A big thank you  to Norman Deaton and Raymond Rye for their assistance with this article.

4 Comments

Filed under dinosaurs, Extinct Monsters, history of science, mammals, museums, NMNH, paleoart, reptiles, science communication

Tagged as , , , , , , , , ,

January 1, 2013 · 4:00 pm

Beating the orthogenetic horse

According to the rad personalized 2012 review provided by WordPress, the top search engine terms leading people here over the last year were dinosours, horse evolutionary tree, horse evolution tree, horse phylogenetic tree and Daspletosaurus. It’s not too difficult to pick out the pattern there – horse evolution seems to be a major draw, even though I only mentioned it in a single post back in June. I aim to please, so I suppose a more detailed discussion of horse phylogeny is in order. First off, let me recommend Brian Switek’s thorough and thoughtful take on the subject. If you stick around here, you’re going to get more of a tirade.

Most depictions of horse evolution available online, including the one I posted a few months ago that is luring people to this site, are terrible. The typical linear presentation of horses progressively increasing in size from Eohippus to modern Equus, losing toes along the way, misrepresents not only what we know about horses as a group, but how evolution works in general.

This didn’t happen.

Evolution is, of course, neither linear nor progressive: it is primarily the result of populations adapting to thrive in their particular environments. As environments change over time species may evolve or go extinct, but there is no predetermined goal that lineages are reaching for. Modern Equus is not the most “highly evolved” horse – this is, in fact, a misleading if not meaningless concept, because a species’ success is dependent on its ability to thrive in that specific time and place. A modern horse is well adapted for grazing and running fast on open plains, but relocate one to the Eocene cloud forests where Eohippus thrived and it would do very badly.

Furthermore, it has been known for over a century that horses as a group did not consistently grow larger over time or otherwise become more Equus-like. Instead, horses diversified into a variety of forms over the group’s 55 million year existence, each group adapting to different environmental niches across the northern hemisphere. Large and small, forest-dwelling browsers and plains-dwelling grazers, these and all manner of other horses overlapped in time and space over the course of the Cenozoic. As J.W. Gidley of the American Museum of Natural History had worked out as early as 1907, horse evolution was not a linear progression but a tangled bush (just like the evolution of most other clades).

A modern horse phylogeny. From Macfadden 2005, via Laelaps.

A modern horse phylogeny. From MacFadden 2005, via Laelaps.

So where did the orthogenetic depiction of horse evolution come from, and why is it still with us today? The answer highlights the importance of museum exhibits and specimen provenance in the public’s understanding of paleontology, with a dose of jealous personalities for good measure.

In 1859, Charles Darwin published On the Origin of Species, in which he articulated the process of evolution by natural selection virtually exactly as we understand it today. Darwin’s book incited a whirlwind of debate in both scientific and public circles because of its implication that the diversity of life could be attributed to natural forces, rather than an unknowable divine power. Within a decade, however, the vast majority of the scientific community was convinced by the soundness of Darwin’s theory, and to this day billions of individual observations of the natural world tell us that evolution is assuredly true.

One of the many lines of evidence covered in On the Origin of Species is the fossil record, with which we can trace the evolution and extinction of organisms over time, including the ancestors of modern life. However, Chapter 9 of Darwin’s book, “On the Imperfection of the Geological Record” (full text pdf) reads like like a lengthy apology for the incomplete nature of fossil preservation. Today, the use of organized, cladistic methodologies allow paleontologists to piece together detailed phylogenies from fossils, but in Darwin’s day, the evidence was patchier, and he opted to de-emphasise the fossil record’s usefulness to avoid such criticism. As Darwin put it, “we have no right to expect to find in our geological formations an infinite number of of those fine transitional forms.” Unfortunately for paleontology specialists, this led other biologists to believe that fossils could not make any independent contribution to the understanding of evolution. Largely shut out of the biggest biological discovery of all time, paleontologists became stewards of a “second-class discipline” (Sepkoski 2012, 9).

Paleontologists in the late 19th century.

Since biologists interested in evolution considered paleontology mostly irrelevant, late 19th-century paleontologists were left with three options. They could support evolution as best they could and accept that other biologists might not take notice, they could ignore theoretical discussion entirely and focus on purely descriptive studies of morphology, or they could be spiteful and seek alternatives to Darwinian evolution. The second course of action was the most popular well into the 20th century. E.D. Cope seems to be  an example of the third approach, favoring an odd sort of neo-Lamarckism in his book The Origin of the Fittest. Such conceptions of directional change, such as Cope’s Law, are counter to evolution as proposed by Darwin and as understood today. However, a handful of paleontologists stuck with it and endeavored to provide meaningful fossil evidence for evolutionary theory.

Throughout the 1860’s, paleontologist O.C. Marsh amassed an impressive array of fossil horses from Wyoming and elsewhere in the American west. Horse fossils had been found in Europe much earlier, but Marsh’s horse collection was much more complete, and was probably the best fossil record compiled for any vertebrate group at the time. In 1870, the influential British naturalist Thomas “Darwin’s Bulldog” Huxley visited Marsh in New Haven and was suitably impressed: Marsh’s fossils ranged from the Eocene up until the Pleistocene, providing a clear picture of how the horse family had evolved over time. While Darwin had been hesitant to make too big a deal about the fossil record as evidence for evolution, the horse fossils were blatant examples of animals changing over time.

During the same visit, Huxley gave a lecture in New York in which he cited the horse fossils as a fantastic new line of evidence in support of evolution. Unfortunately, Huxley’s lecture (while admittedly aimed at a general audience) tread into some severely teleologic territory. As quoted in The Gilded Dinosaur (Jaffe 2000, 162), Huxley told his audience that “the horse is in many ways a most remarkable animal in as much as it presents us with an example of one the most perfect pieces of machinery in the animal kingdom.” He went on to explain how horse ancestors, from the little four-toed Hyracotherium in the Eocene to increasingly large horses like Merychippus and Pliohippus, gradually perfected the design of the modern horse. According to Huxley, over the course of the Cenozoic horses got bigger, faster, leggier, and generally better at being horses as we know them today. Problematically, this essentialist narrative rather misses the point of evolution as described by Darwin. 

Marsh, like Huxley, was an early advocate of evolution,  but his narrative of horse evolution was more on the mark. Marsh concluded that the smaller early horses with brachydont teeth were well suited for life in the rainforests that covered the western United States 50 million years ago. Horses like we know them today emerged as a direct result of the Earth getting cooler and drier over the course of the Cenozoic, and by the end of the Pleistocene the lineages of forest horses were completely extinct. Equus is with us today not because it is the best horse for any circumstance, but because it was most successful during the ice ages that shaped the modern flora and fauna (it also helped that humans figured out that horses are useful and ensured their survival through domestication).

Unfortunately, Marsh was never enthusiastic about public education, and so the progressive view of horse evolution was the one that made it into the public sphere. The history of horses remained a popular example of evidence for evolution, trotted out over the years by prominent biologists like George Simpson and Stephen Gould. Indeed, it was the first good evolutionary story known from fossils, although by no means the last or the best. In the earliest 1900s, Henry Osborn had a major role in solidifying the orthogenetic horse evolution story in the public eye when he curated the exhibit on the subject at the American Museum of Natural History. It is on the basic premise of this exhibit that the textbook, museum, and web descriptions of linear horse evolution that persist to this day are based.

Photo by the author.

The fossil horses of AMNH. Photo by the author.

After the modern biological synthesis, paleontologists realigned with the rest of biology, and the odd pseudo-evolutionary ideas that persisted in paleontological circles began to fall by the wayside. However, orthogenetic ideas remain common in natural history exhibits on horse evolution to this day (in about 62% of them, according to MacFadden et al. 2012). The reason these exhibits have stuck around isn’t entirely clear. MacFadden and colleagues suggest suggest a lack of inertia or funding for the renovation of exhibits is a factor, but they also point out that even some newer exhibits fall back on linear horse evolution.

The biggest problem is that orthogenetic evolution makes more intuitive sense to non-specialists. We often use the word “evolution” to imply improvement, so it would follow that horses should get bigger and better over time. This is an important misconception to overcome, because, as if we need a reminder, only 15% of Americans believe humans evolved from other animals via strictly natural processes, and an even smaller number can correctly articulate how evolution works. Evolution is the fundamental principle underlying everything we see in the natural world, and it is imperative that a correct understanding of how it works is the basis of any biology education. With the proper background, the real story of horse evolution is a great example of how changing climates effect organisms and ecosystems over time. This is helpful for interpreting the ever-important subject of climate change, but it won’t click until the linear horse evolution story is trampled out for good.

References

Jaffe, M. 2000. The Gilded Dinosaur: The Fossil War Between E.D. Cope and O.C. Marsh and the Rise of American Science. New York, NY: Three Rivers Press.

MacFadden, B.J., Oviedo, L.H., Seymour, G.M. and Ellis, S. 2012. “Fossil Horses, Orthogenesis and Communicating Evolution in Museums.” Evolution, Education and Outreach 5:29-37.

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

4 Comments

Filed under AMNH, history of science, mammals, museums, science communication, systematics

Tagged as , , , , , , ,

December 23, 2012 · 8:58 pm

Fossil mounts: specimens, showpieces, art and more

A few days ago, Andy Farke posed the following question on twitter:

If fossils are part of our planet’s heritage, and belong to all of us, are museum restrictions on photos ethical?

Farke clarified that he was referring specifically to fossils held in collections, especially those collected on federal land and/or with public funding. Following the same sound logic that makes open access scientific publication a necessity, any scientific work using public resources should be accessible to everyone, including objects in collections.* The question had arisen because some museums bar researchers utilizing collections from using photographs in their published articles (or charge a fee for the privilege). This is a valid concern, but I don’t have enough experience with scientific publishing to explore it properly. Instead, I’d like to hijack the question in order to discuss the murky identity of fossil mounts.

*I’m going to disregard for-profit museums for the time being, suffice it to say such collections exist and can be useful for research as well.

A sampling of fossil collections and curators at the National Museum of Natural History. Source: http://paleobiology.si.edu.

As was already pointed out in response to Farke’s initial question, the public’s right to access photographs of some fossil collections should not necessarily extend to museum exhibits. Any modern museum exhibit worth its salt is far more than specimens on shelves. Exhibits are immersive experiences that use specimens to illustrate a story. A great deal of creative work goes into designing and fabricating an exhibit, and it is not unreasonable for museums to claim ownership of any reproductions, including photographs, if they so choose.

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

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

Fossil mounts, however, are a different beast. These structures are difficult to categorize because they are intended both to educate and to entertain. They may incorporate real fossils, or casts taken directly from them, but I would argue that fossil mounts are primarily constructed pieces. With the exception of some more recently extinct mammal taxa, most mounts are composites of casts, sculpted elements and original fossils collected in different places at different times. Steel armatures are custom-made not only to support the specimens but to appropriately fill the exhibit space. Mounts like the striking Barosaurus and Allosaurus encounter in the Roosevelt rotunda at AMNH (above) are designed to make an aesthetic impression as well as to inform. Overall, mounts require a substantial investment of time, labor, money and artistic skill to create and maintain. Experienced researchers typically guide the construction process and the contributions of knowledgeable scientists cannot be overstated, but fossil specimens certainly do not come out of the ground mount-ready. There is a great deal more to making a good mount than stringing vertebrae together in the right order.

A direct comparison can be made between fossil mounts and the taxidermied animals that are also a staple at natural history museums. A taxidermy mount also incorporates a scientific specimen, the animal’s skin, which if collected using public resources should be accessible to all. Like fossil mounts, however, taxidermy pieces require extensive artistic and technical skill to create, from the steel or wood armature to the clay model that build’s out the animal’s musculature to the eyes and mouth, which are typically sculpted from scratch. It is worth quoting Rachel Poliquin’s excellent The Breathless Zoo at length:

As dead and mounted animals, [taxidermy mounts] are thoroughly cultural objects; yet as pieces of nature, [they] are thoroughly beyond culture. Animal or object? Animal and object? This is the irresolvable tension that defines all taxidermy. (Poliquin 2012, 5-6)

I firmly believe that the results of scientific inquiry belong in the public domain, and it follows that restrictions on the photographic reproduction of collections specimens are inappropriate. Nevertheless, fossil mounts and taxidermied animals are the products of artisans as much as of researchers, and the right to credit and control over this work ought to be respected. This middle ground is awkward to negotiate, and as Poliquin puts it, a means to please all parties might be “irresolvable.”

Robert Rockwell sculpts the internal model for AMNH's taxidermied brown bear. Source: Scientific American.

Robert Rockwell sculpts the internal model for AMNH’s taxidermied brown bear. Source: Scientific American.

To make a non-committal final point, I’d like to mention that it is tempting to be too uptight about copyright, particularly in a museum setting. This past October, I had the pleasure to give a presentation with Alexis Fekete at the Kansas Museum Association’s annual conference. The most interesting part of our session (which was about how web 2.0 tools can help museums) was when audience members, mostly representing small history museums, voiced concerns over making their photography collections available online. There was apprehension about making it too easy for people to copy and sell pictures without permission, which I assume is the primary reasoning behind other museums’ policies prohibiting the publication of fossil images. I’m skeptical, however, that this is the most pressing concern. Perhaps I’m being naïve, but I have no problem with getting information disseminated to genuinely interested people. Creating awareness and enthusiasm for content is part of the general mission of museums, and I’d hate to see overzealous copyright barriers get in the way of that.

References

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

3 Comments

Filed under collections, dinosaurs, fossil mounts, mammals, museums, science communication

Tagged as , , , , , , , , ,

October 14, 2012 · 7:17 am

On the colonial legacy of fossil collections

Museum workers are no strangers to the colonial legacies of their collections. This issue comes up most frequently regarding anthropological artifacts, but it is relevant to natural history specimens as well. During the 1800s, when colonialism was at its height and western Europe controlled 85% of the world, colonial domination was achieved not only with military power, but through academia. When colonial powers took over another nation, they brought their naturalists, archaeologists and social scientists along to take control of the world’s understanding of that place, its people and its environment. Museums were used as repositories for the man-made and natural relics of conquered lands (which were rarely acquired ethically), and were used to communicate the westerners’ interpretation of those exotic foreign places (or even defend the colonial agenda). In the case of natural history specimens, dioramas incorporating taxidermy mounts portrayed the countries where the skins were obtained as idealized edens unspoiled by human activity.

By the 1960s, however, the backlash against colonially-associated museum collections was in full force. Anthropologists in particular largely disassociated themselves from ethnographic collections, moving their field deep into the theoretical realm. Legislation like NAGPRA codified the idea that western academics do not have sole ownership over the description or interpretation of world cultures. But while NAGPRA and similar legislation renegotiate the ownership of artifacts that are universally agreed to be valuable, colonial-era biological specimens have often been destroyed outright. For instance, in 1960 the Saffron Walden Museum in Essex burned over 200 taxidermy pieces that were considered not in keeping with the museum’s revised mission.

Still, there is one part of museum collections that seems to have slipped past the postcolonial watchdogs unnoticed. I have never seen any consideration of the colonial legacy of fossil collections, and I’m not sure why that should be. Many of our most celebrated paleontological specimens were uncovered during the colonial era, or under other unfortunate historical circumstances (Marsh dinosaurs, disputed American Indian territory, and western expansion…perhaps I will try to cover this in depth later).

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

One obvious example to pick on is the Giraffatitan (Brachiosaurus brancai for purists) on display at Berlin’s Museum fur Naturkunde. The skeleton was assembled from the fossils of at least three Giraffatitan individuals uncovered by a team led by German paleontologist Werner Janensch between 1909 and 1912 in the Tendaguru formation of German East Africa. German East Africa was, of course, a German colony between 1885 and 1919, when it was broken up among Britain and Belgium under the Treaty of Versailles. The bulk of the former German colony became mainland Tanzania in 1961, although it also included parts of modern Burundi and Rwanda. In short, the Giraffatitan was acquired during the German occupation of Tanzania and, following the logic applied to other colonial period artifacts, the museum’s retention of the fossils makes it complacent with the colonial agenda.

The question then becomes, why should a German museum have the right to hold and display these fossils? The Giraffatitan skeleton is part of the natural history of Tanzania, so shouldn’t the Tanzanian people be able to enjoy and learn from their natural heritage without traveling to another continent? If the Museum fur Naturkunde no longer approves of Germany’s past imperial occupation of east Africa (and it assuredly does not), then why should it retain specimens collected in Tanzania without local consent or fair exchange (this is an assumption on my part, anyone who knows better please let me know)?

Excavation of Giraffatitan fossils in German East Africa (now Tanzania), 1909. Image from Wikipedia.

A counterpoint might be that the German museum is better equipped to preserve and maintain these one-of-a-kind fossils than any comparative facility in Tanzania. Having visited most of the major museums in Tanzania, I can say this is probably true. Vertebrate fossils are, after all, extremely rare and priceless specimens that we only get one chance at preserving. It is sensible to want them to get the very best treatment possible (even if limited resources in sub-Saharan Africa can also be attributed to colonial history). Additionally, the Giraffatitan fossils differ from anthropological artifacts in that they are 150 million years old and have no local cultural significance that I am aware of. I hate to bring it up because I am truly sick of the endless debate over the Elgin Marbles, but this is essentially the same situation: local right to one’s own heritage versus the best possible safekeeping.

Should fossils be considered a part of local heritage? Based on the effectively universal support from paleontologists for the Mongolian government when an poached Tarbosaurus skeleton turned up for auction earlier this year, I would assume that relevant experts would think so, and do their part to ensure that nations worldwide have ownership over their fossil treasures. However, a claim can also be made that fossils are far too old to be linked to any particular culture, and instead belong to the world equally. And the best way to share them with the world? Put the fossils where the researchers are, so that knowledge about them can be shared.

Personally, I don’t have a well-formed opinion on what to do with fossils with colonial legacies. What is more interesting to me is why fossil collections have been largely immune to the infighting and legislation that has plagued other collections with problematic histories. Are they less clearly associated with particular nations or cultures than human artifacts or even modern animals? Are there too few vertebrate fossil specimens to matter? Do too few people care about paleontology?

References

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

Dias, N. 2001. “Does Anthropology Need Museums? Teaching Ethnographic Museology in Portugal Thirty Years Later.” In Academic Anthropology and the Museum: Back to the Future. New York, NY: Berghahn Books.

Poliquin, R.  2008. “The Matter and Meaning of Museum Taxidermy.” Museum and Society 6(2) 123-134.

11 Comments

Filed under anthropology, dinosaurs, history of science, museums

Tagged as , , , , , ,

September 23, 2012 · 9:10 am

Extinct Monsters: The Marsh Dinosaurs, Part II

Read the Marsh Dinosaurs, Part I or start the Extinct Monsters series from the beginning.

During the first decade of the 20th century, the United States National Museum paleontology department was located in an offsite building in northwest Washington, DC. It was here that preparators Charles Gilmore, Norman Boss, and James Gidley slowly but surely worked through the literal trainloads of fossil specimens O.C. Marsh had acquired for the United States Geological Survey. The Marsh Collection included unknown thousands of specimens, many of them holotypes, and there was no shortage of gorgeous display-caliber material. Even after the “condemnation of worthless material” Gilmore and his team quickly filled the available exhibit space in the Arts and Industries Building with mounted skeletons.

The Ceratosaurus

With no more display space and plenty more fossils, it was fortunate that the USNM moved to a new, larger building in 1910. In this iconic, green-domed building (now the National Museum of Natural History), the paleontology department received newly furnished collections spaces and the entire east wing to fill with display specimens. The evocatively titled Hall of Extinct Monsters provided a new home for the mounted skeletons already constructed for the old exhibit, as well as plenty of room for new displays.

The Ceratosaurus nasicornis holotype was originally housed in a glass case. Image courtesy of the Linda Hall Library.

Ceratosaurus. Photo by the author.

The delicate arms of Ceratosaurus were removed several years prior to the hall’s closing. Photo by the author.

One of the first new additions was the type specimen of Ceratosaurus nasicornis (USNM 4735), mounted in relief. Marshall Felch led the excavation of this specimen in 1883 at a quarry near Cañon City, Colorado. The nearly complete skeleton received a cursory description from Marsh upon its discovery, but it was Gilmore who described it properly in 1920, ten years after it was put on display. When it was introduced to the Hall of Extinct Monsters, this was the only Ceratosaurus specimen yet found, making the mount a USNM exclusive. The skeleton was originally displayed in a glass case, but during the 1963 renovation it was placed in a more open setting.

Even today, Ceratosaurus is only known from a handful of specimens. For this reason, the original Ceratosaurus fossils will not be returning when the current renovation is completed in 2019. The new hall will instead feature a three-dimensional, standing cast of this skeleton. The original fossils are now in the museum’s collections, available for proper study for the first time in over a century.

The Camptosaurus

In 1912, two mounted skeletons of Camptosaurus, one large (USNM 4282) and one small (USNM 2210), were introduced to the Hall of Extinct Monsters. William Read excavated both specimens at Quarry 13 in the Como region of Wyoming a quarter of a century earlier. Representing the first-ever mounted skeletons of Camptosaurus, these specimens have had a rather complex taxonomical history. Marsh initially described both specimens as Camptosaurus nanus, a new species within the genus Camptosaurus (the type species was Camptosaurus dispar, also coined by Marsh). After the fossils were acquired by the USNM, Gilmore re-described the larger individual as a new species, Camptosaurus browni. This designation remained until the 1980s, when Peter Galton and H.P. Powell determined that C. nanus and C. browni were actually both growth stages of C. dispar.

Regardless of what they are called, both specimens were remarkably well-preserved and reasonably complete. Most of the skeletal elements of the larger Camptosaurus came from a single individual that was found articulated in situ. However, some of the cervical vertebrae came from another specimen from the same quarry, and the skull, pubis, and some of the ribs were reconstructed. Of particular interest is the right ilium, which has been punctured all the way through by a force delivered from above. Gilmore postulated that “the position of the wounds suggest…that this individual was a female who might have received the injuries during copulation.” The smaller “C. nanus” was also found mostly complete, but two metatarsals came from a different individual and the skull and left forelimb were sculpted.

The original pair of Camptosaurus mounts. Image from Backyard Dinosaurs.

Gilmore supervised the creation of both mounts, and constructed the larger individual himself. Norman Boss took the lead on the smaller specimen. As with the other dinosaur skeletons, the mount was centered on an inch-thick steel rod bent to conform to the shape of the vertebral column. Bolts were drilled directly into the vertebrae to attach them to the armature, and the vertebral foramina were filled with liberal amounts of plaster to secure them to the rod. A similar process was used to assemble each of the limbs, and the ribs were supported by a wire cage.

Gilmore aimed to correct many specifics of Marsh’s  original illustrated reconstruction of Camptosaurus. To start, he shortened the presacral region to make a more compact torso. Marsh had also inexplicably illustrated Camptosaurus with lumbar vertebrae (a characteristic exclusive to mammals), which Gilmore corrected. Finally, Marsh had reconstructed the animal as an obligate biped, but Gilmore  determined that “Camptosaurus used the quadrupedal mode of progression more frequently than any other known member of Ornithopoda.” Accordingly, the larger Camptosaurus mount was posed on all fours. The completed Camptosaurus mounts were placed together in a freestanding glass case toward the rear of the Hall of Extinct Monsters. In 1962 the pair was moved to the left of the Diplodocus on the central pedestal of the redesigned exhibit. During the 1981 renovation they were moved a few feet back, so that they were alongside the sauropod’s tail.

This cast replaced the original Camptosaurus mount in 2010. Photo by the author.

This cast replaced the original Camptosaurus mounts in 2010. Photo by the author.

The retired plaster skulls of the original Camptosaurus mounts. Photo by the author.

The retired plaster skulls of the original Camptosaurus mounts. Photo by the author.

Both Camptosaurus skeletons taken off exhibit in 2010 and replaced with a cast of the adult. The delicate fossils, which had suffered from considerable wear and tear over the past hundred years, were stabilized and stored individually for their protection. The new mount has a number of upgrades to reflect our improved understanding of dinosaur anatomy. The arms are closer together and the palms face inward, because the pronated (palms down) hands on Gilmore’s version have been determined to be a physical impossibility. The new mount also features a completely different skull. The rectangular model skull used on the original mount was based on Iguanodon, but new discoveries show that the skull of Camptosaurus was more triangular in shape. Both the adult and juvenile Camptosaurus will appear in the new National Fossil Hall.

The Stegosaurus

The Smithsonian’s first Stegosaurus exhibit was a life-sized model built for the 1904 World’s Fair in St. Louis. This model found its way into the Hall of Extinct Monsters in 1910. In 1913, the model was joined by a mounted Stegosaurus skeleton found at the same Cañon City quarry as the Ceratosaurus. A third Stegosaurus, the holotype of S. stenops, was introduced in 1918. Lovingly called the “roadkill” Stegosaurus, USNM 4934 is remarkable in part because it was found completely articulated. In fact, before its 1886 discovery by Marshall Felch, it was unknown exactly how the animal’s plates were positioned on its back.

Standing Stegosaurus mount and life-size model, circa 1950. Photo courtesy of the Smithsonian Institution Archives.

Stegosaurus

Stegosaurus model, standing mount, and “roadkill” on display in the Hall of Extinct Monsters. Source

All three Stegosaurus displays were moved in 1963 and 1981. In Fossils: The History of Life, the Stegosaurus skeletons were positioned flanking the Diplodocus in the central display area, with the standing mount on the right and the roadkill skeleton on the left. The model Stegosaurus stood opposite the mount. Just like the Triceratops and Camptosaurus, many decades on display took their toll on the standing Stegosaurus, so in 2003 the fossils were removed from the exhibit. Dismantling the Stegosaurus was particularly challenging because of the large amount of plaster applied by the mount’s creators. In some cases the plaster infill had to be removed with hand tools, which put further pressure on the fossils. Additionally, the rod supporting the backbone had been threaded right through each of the vertebrae, and was extremely difficult to remove. A casted Stegosaurus mount in a more active pose was returned to the exhibit in 2004.

Cast of Stegosaurus and Camptosaurus. Photo by the author.

Casts of Stegosaurus and Camptosaurus. Photo by the author.

Roadkill stego

“Roadkill” Stegosaurus in 2014. Photo by the author.

After 110 years on display at the Smithsonian, the model Stegosaurus has been donated to the Museum of the Earth in Ithaca. The roadkill Stegosaurus, however, will feature prominently in the new National Fossil Hall, mounted upright on the wall by the exhibit’s secondary entrance. The 2004 Stegosaurus cast had a number of anatomical issues and will not be returning – instead, it will be replaced by an updated cast made from the same original fossils.

The Marsh dinosaurs have been of critical importance in our understanding of the Mesozoic world, but at this point these fossils are historic artifacts as well. When they were uncovered, the American civil war was still a recent memory, and railroads had only recently extended to the western United States. Before the first world war they had been assembled into mounts, and for more than a century these fossils have been mesmerizing and inspiring millions of visitors. Several of these mounts, including the Triceratops, Ceratosaurus and Camptosaurus, were the first reconstructions of these species to ever appear in the public realm, and therefore defined popular interpretations that have lasted for generations. Some visitors may lament that many of the original specimens have been recently been replaced with replicas, but the fact is that these are irreplaceable and invaluable national treasures. They inform us of our culture, and our dedication to expanding knowledge and our rich natural history. We only get one chance with these fossils, and that is why the absolute best care must be taken to preserve them for future generations.

References

Gilmore, C.W. 1912 “The Mounted Skeletons of Camptosaurus in the United States National Musuem.” Proceedings of the US National Museum 14:1878.

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

Jabo, S. 2012. Personal communication.

Leave a comment

Filed under collections, dinosaurs, exhibits, Extinct Monsters, field work, fossil mounts, history of science, museums, NMNH, ornithopods, reptiles, theropods, thyreophorans

Tagged as , , , , , , ,

July 20, 2012 · 12:09 pm

Extinct Monsters: Ice Age Giants

Click here to start the NMNH series from the beginning.

The old fossil mammal exhibits at the National Museum of Natural History were notable for their sheer diversity. From rabbits to elephants and from bats to whales, virtually every major group of North American mammals, particularly eutherian (placental) mammals, was represented. By my count, there were no less than 48 mounted mammal skeletons on display (not including individual skulls and other parts) in 2014, arranged by time period and distributed across three sizable halls.

The comprehensive nature of these exhibits was largely thanks to C.L. Gazin, head curator of the Division of Vertebrate Paleontology in the 1950s and 60s. During the modernization of the fossil halls in the early 1960s, Gazin focused his efforts on assembling a complete narrative of Cenozoic mammal evolution. The six-part exhibit debuted in 1961 in Hall 5, and was relocated two decades later to Hall 3. Gazin also initiated the construction of the adjacent Ice Age exhibit, although it would not be permanently opened to the public until 1974.

Now that the fossil halls are being renovated, NMNH staff face the enormous task of disassembling and restoring the dozens of historic mammal skeletons. Many will return when the exhibit reopens in 2019, but others may be retired to the collections if they are deemed too fragile for continued display, or if they are not illustrative of the story being told in the new exhibit.

The Megaloceros

This Megaloceros

This Megaloceros has the distinction of being the Smithsonian’s first mounted skeleton composed of original fossils. Photo by the author.

The Smithsonian’s first mounted fossil skeletons went on display in 1871 in the building colloquially called “the castle.” The exhibit included plaster casts of the ground sloth Megatherium, the tortoise Colossochelys and the glyptodont Scistopleurum, all made from originals at the British Museum. The following year saw the addition of the giant deer Megaloceros (USNM V 7051) — the Smithsonian’s first mounted skeleton composed of original fossils. The Smithsonian purchased this complete Megaloceros, which was uncovered in an Irish peat bog, from Philadelphia-based antiques dealer Thomas and Sons. The mount was assembled by none other than Benjamin Waterhouse Hawkins, the sculptor who created the famous Crystal Palace dinosaurs.

Note basilo

Megaloceros in the southeast court of the Arts and Industries building, circa 1896. The British Museum Megatherium cast can be seen on the left. Source

When construction of the original United States National Museum (what is now called the Arts and Industries Building) was completed in 1881, all of the fossil displays were moved to the new setting. Vertebrate fossils found a home in the 80,000 square foot southeast court. Gradually, the Megaloceros and British Museum casts were joined by many more crowd-pleasing skeletons, including a copy of the Philadelphia Hadrosaurus, an Edmontosaurus, a Triceratops, and a mastodon (discussed below). By the time the USNM was preparing to move to yet another new building across the national mall in 1910, the southeast court had become quite crowded. Unfortunately, the Megatherium and Collossochelys never made it to the new location. These casts were discarded due to the damage they had accumulated while on display. Although the glyptodont cast was still on exhibit as of 1940, it too was eventually destroyed. Happily, the Megaloceros survived, and has been included in each subsequent iteration of the fossil exhibits.

Starting in 1974, the Megaloceros was displayed alongside the extinct bird Diornis in the Ice Age hall. It’s weight was partially supported by cables descending from the ceiling, which proved to be a problem when it came time to disassemble it in July 2014. Rather than attempting to lift the delicate skull and heavy antlers off the armature, the exhibit team strapped the skull to a mechanical lift so that it could be slowly and gently lowered to the floor. In the new National Fossil Hall, the Megaloceros will be sitting on the ground. This pose was selected in order to bring the spectacular antlers to visitors’ eye level.

The Mastodon

The Indiana mastodon in the Hall of Extinct Monsters. Photo courtesy of the Smithsonian Institution Archives.

In 1901, Michigan farmer Levi Wood found a well-preserved, nearly complete Mammut americanum (USNM 2106) in a peat swamp on his land. The USNM purchased the rights to excavate the skeleton from Wood and began work that same year. The specimen turned out to be virtually complete, save for the forelimbs and left hindlimb. Alban Stewart mounted the skeleton, adding a left hindlimb from another mastodon specimen from Missouri, and filling in other missing elements with plaster replicas. The completed mount was first exhibited at the Louisiana Purchase Exposition in St. Louis, Missouri in 1904.

For a time, there were two mastodon mounts on display in the Hall of Extinct Monsters. Photo courtesy of the Smithsonian Institution Archives.

After the Exposition, the Michigan mastodon was added to the fossil displays in the  southeast court of the Arts and Industries Building. It remained there for four years, before joining the rest of the paleontology exhibits and collections in the move to the new USNM building.

In 1915, a second mastodon (USNM V 8204) from Indiana was added to the Hall of Extinct Monsters. The matching set can be seen on the left side of the image above, with the plaster skull of a Deinotherium (USNM V 1917) positioned between them. The larger Indiana mastodon persisted through the 1963 and 1981 renovations, and will return with an energetic trumpeting pose in 2019. NMNH loaned the Michigan mastodon to the Oregon Zoo for many years. It has since been returned, dismantled, and retired to the collections.

The Stegomastodon

Stegomastodon in 2014. Photo by the author.

Stegomastodon in 2014. Photo by the author.

The young male Stegomastodon (USNM 10707) was collected by James Gidley and Kirk Bryan collected this skeleton in the San Pedro Valley of Arizona. This 1921 collecting trip also produced the museum’s Glyptotherium. While the genus Stegomastodon was erected in 1912, Gidley referred his specimen to a new species, S. arizonae, due to its more “progressive” physiology and slightly younger age. By 1925, the skeleton was mounted and on display in the Hall of Extinct Monsters. While the original mount used the real fossil tusks, these were eventually replaced with facsimiles.

Stegomastodon with

Stegomastodon with its original tusks. Photo from Gidley 1925.

The Stegomastodon will not be returning when the National Fossil Hall reopens in 2019. For one thing, there are already two big elephants on display: the mammoth and the mastodon. Elephants take up a lot of space, and a third proboscidean offers diminishing returns when compared to the amount of floor space it requires. More importantly, the Stegomastodon is a holotype specimen, and the exhibit team elected to remove most of these important specimens from the public halls. This is both to keep them safe from the damaging effects of vibration, humidity, and fluctuating temperature, as well as to make them more accessible to researchers.

The Eremotherium pair

Eremotherium

The unique and impressive Eremotherium pair. Photo by the author.

The immense pair of giant ground sloths (USNM V 20867 and USNM V 20872) are among the most impressive and unique skeletal mounts at NMNH. Many a visitor has ascended the ramp to the Ice Age gallery only to stop and stare at them. Unlike the Megaloceros, mastodon, and many others, these were new additions added during the 1960s modernization. Gazin’s team recovered the fossils in Panama between 1950 and 1951, bringing back over 100 plaster jackets representing at least eight individual sloths of the genus Eremotherium.

sou

John Ott and Gladwyn Sullivan attach the scapula of the standing sloth. Source

Assistant Curator of Cenozoic Mammals Clayton Ray oversaw the assembly of the two Eremotherium mounts in 1969. Both the larger standing sloth and smaller kneeling one are composites of fossils from many individuals (there are also plenty of reconstructed bones, easily spotted by their solid beige coloration). Most of the surplus bones were repatriated to Panama before the mounts went on display. The sloths were originally positioned back-to-back on a central platform, accentuated by an illuminated opening in the ceiling. However, this layout only lasted a few years. In 1974, the Quaternary Hall was completely reorganized into the Hall of Ice Age Mammals and the Age of Man. In the new arrangement, the Eremotherium pair was relocated to a corner at the north end of the gallery. In 2019, only one Eremotherium will be on display.

The Mammoth

Chimera mammoth

This mammoth was assembled from as many as 70 individual specimens. Photo by the author.

Although it was always labeled as a woolly mammoth (Mammuthus primigenius), the Smithsonian’s third proboscidian skeleton (USNM V 23792) is actually a composite of over fifty individual specimens, some of which probably belong to the more southerly Columbian mammoth (Mammuthus columbi). Most of these fossils were acquired in a trade with the American Museum of Natural History in the 1960s, specifically to build a mounted skeleton for the Ice Age hall. Perhaps because they were acquired for display, rather than study, the origin of these fossils was not well-recorded. It is only now that the mammoth has been disassembled that collections staff can begin to to learn more about this iconic chimera. Some of the bones are marked with the year and location of their collection, crucial details for piecing together their provenance.

The mammoth in its new, snow-shoveling pose. Photo courtesy of the Smithsonian Newsdesk.

In the new fossil hall, the mammoth will be leaning forward, pushing its great tusks across the ground as though it were brushing away snow. In the meantime, the original mount was digitally scanned, and the model is freely available from Smithsonian 3D.

References

Carrano, M. 2018. Pers. comm.

Gazin, C.L. 1956.  Exploration for the remains of giant ground sloths in Panama. Smithsonian report, 341-354.

Gidley, J.W. 1925. Fossil Proboscidea and Edentata of the San Pedro Valley, Arizona. Shorter Contributions to General Geology (USGS). Professional Paper 140-B, 83-95.

Gilmore, C.W. 1906. Notes on Some Recent Additions to the Exhibition Series of Vertebrate Fossils. Proceedings of the United States National Museum No. 30.

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

3 Comments

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

Tagged as , , , , ,