Tag Archives: Smithsonian

July 10, 2015 · 12:13 pm

Framing Fossil Exhibits: Environmental Change

Over the past few months, I’ve been writing about the strengths and weaknesses of various large-scale paleontology exhibits from an educational standpoint. Check out the Introduction, Walk Through Time, Phylogeny, and Habitat Immersion posts if you’d like to catch up. I’ll wrap up this series for the time being with a look at two upcoming renovations of classic fossil displays, which appear to have converged on similar aesthetic, organizational, and interpretive approaches.

First up is the Peabody Museum of Natural History, where the Great Hall of Dinosaurs and adjacent Hall of Mammal Evolution have seen little modification since the 1950s. While the PMNH fossil galleries are fascinating as a time capsule of mid-century exhibit design, much of the content is rather dated and a thorough overhaul is sorely needed. PMNH staff started planning for the renovation in 2010, and I highly recommend Collections Manager Chris Norris’s blog posts on the process. Once the basic layout and concepts were in order, the museum hired the architectural firm Studio Joseph to prepare the images being used to promote the project. Fundraising is now underway, but an estimated completion date has yet to be announced.

Conceptual render of the Great Hall of Dinosaurs by Studio Joseph. Source

The big idea behind the new exhibit is the dynamic relationship between the biosphere and the Earth’s various other spheres (atmosphere, geosphere, hydrosphere, etc). The evolution of life on Earth did not occur in a vacuum, but as part of a continuously changing global system. This narrative does have a time axis – visitors will travel from the Permian at one end of the exhibit to the Quaternary at the other – but the precise divisions of geologic time are de-emphasized in favor of the broad environmental transitions that triggered evolutionary innovations. Examples might include the separation of continents during the Mesozoic, the diversification of flowering plants in the Cretaceous, or the massive climatic shift at the end of the Eocene. In this context, it’s more important that visitors understand (for example) that the Cenozoic was generally a transition from hot and wet to cold and dry (and the implications on mammalian evolution) than that they know the names and time spans of each epoch.

This approach contrasts sharply with traditional chronological exhibits, such as the Field Museum of Natural History’s “Evolving Planet.” The FMNH fossil galleries are extremely linear, and each geologic period is introduced with a set of easily-digested bullet points summarizing what happened during that time. Relatively tight spaces prevent visitors from seeing specimens from other time periods prematurely, and the galleries devoted to each period are color-coded to make them immediately distinct. According to Norris, this segmented presentation of the history of life obscures the large-scale transitions which transcend the somewhat arbitrary divisions of geologic time. As such, the new PMNH fossil halls will present the narrative holistically, encouraging visitors to track the underlying environmental trends that precipitated evolutionary change over time.

mammal hall concept art by Studio Joseph

Conceptual render of the Hall of Mammals by Studio Joseph. Source

As is immediately clear from the promotional images, the new exhibit will juxtapose a modern, wide-open aesthetic with elements of the museum’s past – specifically, the outdated but gorgeous Rudolph Zallinger murals. Both of these design elements tie directly to exhibit’s narrative themes. By breaking up the central dinosaur pedestal and eliminating the unsightly glass cases in the Mammal Hall, the exhibit designers have dramatically increased the available floor space and opened up new lines of sight. This should allow visitors to view each of the galleries comprehensively, rather than as a series of discreet segments. Meanwhile, the Zallinger murals will remain a celebrated part of the exhibits. These magnificent frescoes were painted between 1942 and 1967, and are among the most iconic images of prehistoric life ever created. Although the physiology of some of the animals is outdated, Zallinger was in other ways ahead of his time. Rather than giving the geologic periods hard borders, Zallinger artfully wove the sections together so that each one fades imperceptibly into the next. The viewer can see that the flora, fauna, and climate are changing over time, but it’s a gradient, not a ladder, which perfectly reflects the narrative of the new exhibit.

A conceptual render of Deinonychus and other Cretaceous fossils. Source

About 300 miles south of PMNH, the re-imagining of the fossil halls at the National Museum of Natural History is well underway. This building’s east wing has been home to paleontology displays since it opened in 1910 and has been updated several times, but this is the first time it has undergone a complete, wall-to-wall modernization. The old exhibits were formally closed on April 28th, 2014, and NMNH staff spent the following year removing thousands of specimens from the halls. With the fossils out of the way, the next step will be to restore the historic space to its original neoclassical glory. After that, the new exhibits and updated fossil mounts can be assembled in time for a 2019 re-opening.

Intriguingly, the planned design of the new National Fossil Hall is both thematically and aesthetically similar to the PMNH renovation, albeit on a grander scale. The National Fossil Hall’s narrative focus will be on large-scale environmental transitions over time, and how these changes drove the evolution of plants and animals. Like at PMNH, this will be accentuated by an open layout: false walls and barriers that have divided the space since the early 1960s will come down, allowing visitors to see clear across the spacious three-story hall. This airy aesthetic hearkens back to the Hall of Extinct Monsters, and like the restoration of the Zallinger murals at PMNH it represents an admirable celebration of the institution’s history.

Early conceptual render of the National Fossil Hall by Reich + Petch Source

One interpretive choice that will set the National Fossil Hall apart is the clustering of specimens on islands, or “pork chops”, as the were called early in development. Each pork chop represents North America at a particular period in time. While anchored by a few charismatic mounts, the pork chops will also include all manner of small animals, invertebrates, and plants that were part of that environment. In this way, the islands are self-contained mini exhibits, each one showing a complete ecosystem that existed at a particular time. Moving among the these displays, visitors should get a sense of how climate change and faunal interchange (among other phenomena) can completely transform an ecosystem over millions of years. They’ll also learn how certain organisms, like sauropods in the Jurassic or grass in the Neogene, can change landscapes and influence the evolution of contemporary plants and animals.

The emphasis on open spaces and freedom of movement is notable, because this is quite different from the linear exhibits of the late 20th century. In recent decades, exhibits have become increasingly structured, with specific learning goals and physical spaces designed to corral visitors through a carefully orchestrated narrative journey. Again, Evolving Planet at FMNH is an excellent example of this philosophy. The new National Fossil Hall is in some ways a push in the opposite direction – although it has a clear narrative and overarching message, visitors can roam through the exhibit as they please. I see the pork chop system as a way to have it both ways. Whether visitors work through the exhibit front to back or run straight to the T. rex in the center of the hall, then wander around at random, they’ll still be able to compare and contrast the different ecosystems and learn what the designers want them to learn.

Early concept art of the Jurassic “pork chop.” Image from The Last American Dinosaurs, NMNH.

More than anything else, what I expect to set the National Fossil Hall apart from peer exhibits will be its explicit connections to modern-day environmental crises. It’s worth quoting the Department of Paleobiology’s summary in full:

Visitors to the Museum will be able to explore how life, environments, and ecosystems have interacted to form and change our planet over billions of years. By discovering and harnessing the tools and methods paleobiologists use to study fossils, visitors will gain a deeper understanding of how the world works.

The distant past affects all of us today and will continue to do so in the future. How will climate change impact the natural world and our daily lives? How can we make informed choices about our ecosystems as individuals and as a species? How can we all become informed citizens of a changing planet?

We are in the midst of an extinction event of our own making. Anthropogenic climate change, habitat destruction, and invasive species are as dangerous as any asteroid, and will likely have profound effects on our own lives and livelihoods in the coming century. But while humans are undeniably the cause of the latest round of global changes, we also have the power to mitigate and manage their consequences. The study of fossils provides important contextual information – we can place modern organisms in an evolutionary context and understand their role in shaping the world as we know it, and we can see how organisms have responded to significant environmental overhauls in the distant past. The fossil record is in fact the only way to directly observe these things (as opposed to relying on models or actualistic experiments). As such, the new National Fossil Hall will make it clear that paleontology isn’t just about historical curiosity. The study of past life gives us a long view of the Earth’s biotic and abiotic systems, and helps us predict how they will respond to today’s environmental changes.

Concept drawing of the National Fossil Hall’s Cretaceous zone. In the old hall, the viewer would be standing at the base of the mezzanine stairs facing the rotunda. Source

With the modern climate crisis front and center, the new National Fossil Hall has the potential to be one of the most immediately relevant and important paleontology exhibits ever assembled*. This is significant, because as I lamented when I started this series, immediacy and relevance are not things that most museum visitors expect from fossil displays. While fossils, particularly the mounted skeletons of dinosaurs and other prehistoric animals, have been central to the identity of natural history museums since the late 19th century, most visitors don’t regard these exhibits as anything more than prehistoric pageantry. Visitor surveys consistently reveal that dinosaurs are seen as eye candy – monsters that might as well be from another planet. This is a shame, because dinosaurs and other prehistoric organisms were real parts of our own world, and we can learn much from them.

The new National Fossil Hall will be arranged in reverse chronological order – as visitors move accross the gallery, familiar elements of modern environments will be stripped away and the world will become an increasingly alien place. Source

And so we come full circle. What is the point of a museum exhibit**? Is it enough to provide visitors an opportunity to see cool objects and specimens? When we ask museumgoers what they want to see, they tell us “dinosaurs” or “fossils.” They don’t ask for compelling narratives or connections to big contemporary issues, and they don’t see their museum visit as an important way to bridge gaps in scientific literacy.

Still, it is of critical importance that we provide these narratives and connections. Even if we accept the fact that the very existence of a museum and the chance to see real specimens is a Good Thing, museums are still accountable to the public. Virtually all museums cite education as the primary purpose of their institution, and it’s imperative to live up to that. A museum should have a learning goal in mind, it should be able to prove that this message is coming across, and it should be able to articulate why its audience is better off for it. This is not necessarily easy – exhibits need to be relevant without being condescending or preachy. Exhibit designers need to understand their visitors as much as their content. They need to find a balance between feeding visitors information and providing a customizable experience for diverse audiences. As we have seen, not every exhibit succeeds, but my impression is that we’re getting better at it.

*It’s also notable that this climate change-focused exhibit will be on the national mall, given the ongoing politically-motivated opposition to climate science.

**Note that I’m referring specifically to public-facing exhibits. There are many good reasons why the ongoing maintenance of natural history collections is intrinsically valuable.

References

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

Weil, S.E. (2002). Making Musueums Matter. Washington, DC: Smithsonian Books.

Werning, S. (2013). Why Paleontology Is Relevant. The Integrative Paleontologists. http://blogs.plos.org/paleo/2013/02/19/why-paleontology-is-relevant

6 Comments

Filed under dinosaurs, education, exhibits, FMNH, museums, NMNH, opinion, PMNH, science communication

Tagged as education, evolution, exhibits, Extinct Monsters, museums, natural history museums, NMNH, paleontology, Peabody Museum, science communication, scientific literacy, Smithsonian

June 8, 2015 · 3:48 pm

A Trio of Tyrants

The frentic search for North American dinosaur fossils in the late 19th and early 20th centuries can be divided into three phases. First came O.C. Marsh and E.D Cope, whose infamous rivalry resulted in literal trainloads of fossil material and laid the groundwork for our present understanding of dinosaur diversity. Next, teams sponsored by the newly-formed American, Carnegie, and Field museums returned to the same hunting grounds in the western interior to secure display-worthy specimens for their great halls of exhibition. The final phase was smaller in scale but yielded dinosaur specimens so spectacularly complete that most have gone unmatched to this day.

This third fossil rush occurred not in the United States but in Canada, along the cliff-like banks of Alberta’s Red Deer River. Fossil hunting in this region was pioneered in the late 1800s by George Dawson, Joseph Tyrell, and Lawrence Lambe, all working for the Canadian Geological Survey. This success did not go unnoticed by the the American Museum of Natural History’s Department of Vertebrate Paleontology. In 1910, the museum mounted an expedition led by Barnum Brown to the Red Deer River. Rather ingeniously, Brown’s team acquired a pair of 30-foot floating barges, which were used as mobile platforms from which they could excavate the steep river banks. The barges also served as floating campsites and a handy means of transportation in a region without reliable roads.The adventurous Brown was already a media favorite, and the publicity surrounding his Alberta expeditions only increased when the team started bringing back fully articulated and nearly complete dinosaur skeletons (including several with skin impressions).

Under pressure from constituents concerned that the Americans were hauling away so much of their natural heritage, the Canadian government formed its own team of fossil collectors in 1912. The new Canadian Geological Survey team was headed by independent fossil hunter Charles H. Sternberg (a veteran collector who had once worked for Cope) and his sons George, Levi, and Charles Jr. The Canadian and American teams worked in the same region for the next five field seasons. Their rivalry was usually good-natured, but on more than one occasion Brown saw fit to grumble about the Sternbergs’ ethics (never mind that he was the one permanently removing fossils from their country of origin).

Three tyrannosaurs mounted in relief at AMNH. Image courtesy of the AMNH Research Library.

All of this is so much preamble for the actual topic of this post – three remarkable Gorgosaurus skeletons* collected near the Red Deer River during the Canadian fossil rush. All three were eventually mounted in relief by AMNH preparator Peter Kaisen, and for a time they were displayed together in the Hall of Fossil Reptiles. These specimens are on the short list of most complete large theropod dinosaurs ever discovered, and in their day they provided researchers an unprecedented look at the physiology of these amazing animals. Nearly a century later, the three mounts are virtually unchanged. Locked behind glass for decades and largely inaccessible to researchers, the mounts themselves are now relics of a fascinating transitional period in the history of dinosaur studies.

*AMNH also recovered a fourth tyrannosaur during this period – Gorgeous George the Daspletosaurus.

As usual, a brief explanation of nomenclature is required. William Matthew and Barnum Brown originally described these specimens as Gorgosaurus, a genus that Dale Russell sank into Albertosaurus in 1970. Most specialists no longer support this synonymization, but the specimens at AMNH are still labeled as Albertosaurus.

Gorgosaurus libratus – USNM 12814

A recent photo of USNM 12812 from the ongoing renovation of the national fossil hall. Source

USNM 12814 (originally designated AMNH 5248) was excavated by Brown’s company in 1913 and prepared for display in 1918. Kaisen elected to recreate the death pose in which the Gorgosaurus was found, with its head swept backward over its body. All told, the finished mount included a skull, a complete set of cervical and dorsal vertebrae, complete forelimbs, and a single femur – the pelvis and the rest of the hindlimbs were filled in with casts from other specimens. Since the skeleton was mounted in relief, Kaisen simply painted the tail onto the backdrop.

After at least a dozen years on display at AMNH, the Gorgosaurus was traded to the National Museum of Natural History as part of a complicated deal between the two museums. While surveying fossil collections throughout the United States, Brown realized that a single Barosaurus skeleton from Dinosaur National Monument had been divided among three different institutions. NMNH had the neck and part of one forelimb, the Carnegie Museum had the tail, and the University of Utah had the rest. Between 1929 and 1933, Brown arranged a series of trades in order to unify the Barosaurus at AMNH. The Smithsonian in particular drove a hard bargain – the museum had already invested $3400 in preparing their Barosaurus section, and paleontology staff wanted a good return for their investment. Brown’s initial offer was the fully prepared and mounted Gorgosaurus. Although AMNH valued the field and prep time spent on the fossils at $4573, it was at that point a duplicate specimen taking up valuable space in their increasingly crowded exhibit hall.

NMNH dinosaur specialist Charles Gilmore confided in Brown that he was okay with this trade, but fellow Smithsonian paleontologist Alexander Wetmore wasn’t sold. For years, NMNH staff had been trying to acquire one of the many Moropus specimens AMNH had collected at the Agate Fossil Beds in Nebraska. NMNH had offered a variety of specimens to trade, even sending AMNH a set of brontothere skulls at one point, but AMNH was adamant the Moropus fossils could only be exchanged for cash. Brown really wanted that Barosaurus neck, so in January of 1933, he finally relented and offered the Smithsonian a largely complete Moropus in addition to the Gorgosaurus. Not long after, the Gorgosaurus relief mount found its way into the Hall of Extinct Monsters at NMNH.

Gorgosaurus sp. – AMNH 5458

A technician (probably Kaisen) adjusts the steel strap holding the femur in place. Source

Brown’s team found their second Gorgosaurus near Steveville, Alberta in 1914. Complete save for the left leg, right arm, and parts of the rib cage and tail, the mount was ready for display in May of 1921. At 24 feet long and 14 feet high, this was by far the largest relief mount at the museum. In fact, it was too big to fit through the workshop doorway in one piece, so Kaisen constructed it in eight sections that were sealed together in the exhibit hall. Each section had its own wooden frame for support, and the bones themselves were held in place with steel straps. The skull, jaw, and left forearm could be removed for individual study. This was unusual for the period (most contemporary fossil mounts were designed to be permanent) and speaks volumes about this specimen’s unique scientific value.

This mount is particularly notable for its awkward running pose. Directly contradicting many narratives of early 20th century paleontology, Matthew and Brown envisioned Gorgosaurus as an animal that “walked and ran much like a gigantic bird.” The AMNH team posed this mount after studying photos of bipedally running lizards, particularly the western tiger lizard*. However, Matthew and Brown noted that the dinosaur’s limb proportions and range of motion more closely resemble a bird than a lizard, and adjusted the pose accordingly. They also advised a more conservative stride length to compensate for the animal’s considerable weight.

*Matthew and Brown do not provide a scientific name, and the common name “western tiger lizard” doesn’t seem to be used any more. Anyone know what it’s called today?

The final pose was a compromise between the elevated torso of a running lizard and the comparatively tight gait of a bird. It looks more than a little strange, but AMNH 5458 is certainly closer to our present understanding of theropod posture than most mounts of the era. Matthew and Brown’s interpretation of Gorgosaurus turned out to be ahead of its time. Some contemporary researchers, including Lawrence Lambe, declared the running pose to be highly improbable, and virtually all theropod mounts constructed over the next 60 years returned to the tail-dragging posture of the 1915 AMNH Tyrannosaurus.

Gorgosaurus “sternbergi” – AMNH 5664

Gorgosaurus “sternbergi” as it was discovered and originally mounted. Source

The most complete tyrannosaur from the Red Deer River was not collected by the AMNH party, but by the Sternbergs. The elder Charles Sternberg discovered the specimen in 1917, entirely intact save for the left arm and the very end of the tail. In fact, this was the most complete large theropod ever found in North America until it was surpassed by yet another Gorgosaurus, TCM 2001.89.1. Sternberg first attempted to sell the specimen to the British Museum. They weren’t interested, but AMNH was. In 1918, the Department of Vertebrate Paleontology bought the skeleton for $2000, thus completing the tyrannosaur trio.

Matthew and Brown described AMNH 5664 as a new species – Gorgosaurus sternbergi. In their 1921 publication, they describe the skull as longer and shallower than other Gorgosaurus specimens, with rounder orbits. However, Brown and Matthew recognized that these could be juvenile characteristics, noting as well that the unfused pelvic bones were an indication of immaturity. As early as 1970, this specimen was suspected to be a juvenile Gorgosaurus (or Albertosaurus) libratus.

Kaisen prepared the relief mount in 1921, this time assisted by Carl Sorenson. The photo above shows the original version of this mount, with the tail projecting straight back from the body. This was how Sternberg discovered the skeleton, and Kaisen wanted to keep the death pose intact. In the 1950s, the tail was “corrected” to make it drag on the ground. Although the display has not been altered since, the revised tail posture is now considered inaccurate. Indeed, the vertebrae apparently had to be angled unnaturally to make the dragging tail work at all.

AMNH 5027 was restored and remounted in 1995.

The Gorgosaurus plaque mounts hide behind Tyrannosaurus rex at AMNH. Photo by the author.

All three Gorgosaurus specimens were first displayed in the cramped quarters of the Hall of Fossil Reptiles (now the Hall of Primitive Mammals) with the rest of the growing AMNH dinosaur collection (USNM 12814 and the tail of AMNH 5664 are barely visible in this photo). 5458 and 5664 moved to the newly opened Great Hall of Dinosaurs in 1922. They flanked the gallery’s rear doorway for 70 years before being moved to the Hall of Saurischian Dinosaurs in 1994. Meanwhile, the Gorgosaurus transferred to the Smithsonian first appeared in the Hall of Extinct Monsters in the 1940s, displayed behind glass on the north wall. It switched to the south side in 1962, and moved about 30 feet up the wall in 1981, where it could only be properly seen from the mezzanine ramp.

Aside from the aforementioned alternation to AMNH 5664’s tail, the Red Deer River Gorgosaurus trio has not been modified since they were first built. This may well change in the not-to-distant future. The NMNH crew is hard at work on a thorough renovation of the national fossil hall, dismantling and restoring all of the classic dinosaur mounts. Meanwhile, the current AMNH paleontology exhibits are now 20 years old, and will soon be due for a similar overhaul. Both institutions will need to decide whether or not to free the Gorgosaurus specimens from their plaster substrate. This would be an extremely difficult process, but not impossible – Phil Fraley Productions recently rebuilt the Carnegie Museum’s Corythosaurus, Dryosaurus, and Camptosaurus as free-standing mounts. Dismantling the relief mounts would give a new generation of scientists access to these important specimens, and it would allow for the skeletons to be given more accurate poses. In addition, a standing Gorgosaurus mount alongside either museum’s Tyrannosaurus rex would be both informative and awesome.

Nevertheless, remaking these mounts would also destroy significant historical context. The carefully restored death pose of USNM 12812 seems like something worth preserving, and the AMNH specimens represent an important transitional period in the history of dinosaur science. In the past, museums have often taken a “science marches on” approach when updating aging displays, but in these mounts might be unique enough in their current form to be left as-is. What do you think?

References

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

Colbert, E.H. (1968). Men and Dinosaurs: The Search in Field and Laboratory. New York, NY: E.P. Dutton & Co., Inc.

Gilmore, C.W. (1946). Notes on Recently Mounted Reptile Fossil Skeletons in the United States National Museum. Proceedings of the United States National Museum Vol. 96 No. 3196.

The Long Road to a Fossil Swap. Digging the Fossil Record, March 19, 2015. http://nmnh.typepad.com/smithsonian_fossils/2015/03/gorgosaurus-and-moropus.html

Matthew, W.D. and Brown, B. (1923). Preliminary Notices of Skeletons and Skulls of Deinodontidae from the Cretaceous of Alberta. American Museum Noviates 89: 1-10.

Russell, D. (1970). Tyrannosaurs from the Late Cretaceous of western Canada. National Museum of Natural Science Publications in Palaeontology 1: 1–34.

3 Comments

Filed under AMNH, dinosaurs, field work, fossil mounts, history of science, museums, NMNH, reptiles, theropods

Tagged as Barnum Brown, C.H. Sternberg, dinosaurs, fossil mounts, history of science, museums, natural history museums, NMNH, paleontology, Smithsonian

May 4, 2015 · 7:30 pm

Extinct Monsters: The Marsh Dinosaurs, Part III

A close-up of Allosaurus. Photo by the author.

Click here to start the NMNH series from the beginning.

Some time ago, I wrote about the O.C. Marsh dinosaurs at the National Museum of Natural History. These are the mounted skeletons made from the enormous collection of fossils Marsh accumulated while working for the United States Geological Survey – if you’d like, you can catch up with Part 1 (on Edmontosaurus and Triceratops) and Part 2 (on Camptosaurus, Ceratosaurus, and Stegosaurus). Looking back, I noticed that I never actually finished, so here are the two Marsh dinosaurs with as-yet untold stories.

The Thescelosaurus

The name Thescelosaurus neglectus means “neglected wonderful lizard”, because Smithsonian paleontologist Charles Gilmore found the original specimen at the bottom of a crate, more than 10 years after it arrived at NMNH. Still buried its its field jacket, this skeleton had been long overlooked by both Marsh and the museum staff. Nevertheless, Gilmore found that it was remarkably complete and that it represented a taxon new to science.

An illustration of the Thescelosaurus holotype prior to reconstruction. Source

Thescelosaurus as displayed after 1981. Photo by Chip Clark.

The specimen that would become the Thescelosaurus holotype (USNM 7757) was excavated by John Bell Hatcher and William Utterback in July of 1891, while they were collecting for Marsh in Niobrara County, Wyoming. 20 years later, Gilmore discovered that the skeleton was articulated and intact, save for the head, neck, and parts of the shoulder. He even found small patches of preserved skin on the tail and legs. According to Gilmore, the animal had been buried rapidly after death, since it showed no signs of dismemberment by scavengers.

After describing the fossils, Gilmore mounted the Thesclosaurus in relief on its left side. Other than the reconstructed skull (modeled after Hypsilophodon), the specimen was displayed almost exactly as it was found. This was important to Gilmore, because as he wrote in his published description, “I am…of the opinion that specimens so exhibited hold the attention of the average museum visitor far longer and arouse a keener interest in the genuineness of the specimen than does a skeleton that has been freed from the rock and mounted in an upright, lifelike posture.” Today at least, I suspect that the opposite is true – visitors are generally more impressed by dynamic standing mounts than by reliefs that preserve death poses. Still, it’s fascinating to gain a small amount of insight into the motivations of a pioneering mount-maker.

Although it was first displayed in the Hall of Extinct Monsters, the Thescelosaurus was most prominently exhibited in the 1963 version of the NMNH fossil halls. Here, it joined the Edmontosaurus, Gorgosaurus, and partial Corythosaurus relief mounts along the south wall. In life, these animals were vastly removed from one another in time and space, but displayed together they almost appeared to be parts of a single quarry face. The Thescelosaurus moved to the north wall in 1981, unfortunately placed rather high and out of most visitors’ line of sight.

Thescelosaurus cast in the RCI workshop. Source

Close-up of the new Thescelosaurus skull. Source

When the new National Fossil Hall opens in 2019, USNM 7757 will be replaced with a duplicate cast. The original bones will be moved to the collections, where they can be properly studied for the first time in a century. Already, technicians at Research Casting International have freed the skeleton’s left side, which had never been fully prepared. The exhibit replica assembled by RCI is beautiful, retaining the ossified tendons and cartilage impressions of the original. Mounted in a running pose, the new cast also features an updated head, based on Clint Boyd’s recent description of Thescelosaurus cranial anatomy.

The Allosaurus

Built in 1981, the Allosaurus fragilis (USNM 4734) was the last Marsh Collection dinosaur to be mounted, although bits and pieces have been on display at NMNH since 1920. There has been considerable interest in this individual recently, in part because Kenneth Carpenter and Gregory Paul proposed in 2010 that it become the neotype for Allosaurus – more on that in a moment. Others are interested in this specimen because of its unique pathologies. In addition to several broken and healed bones, the Allosaurus has a massive puncture wound on its left scapula, which nicely matches the diameter of a Stegosaurus tail spike.

Benjamin Mudge collected this specimen in 1877 near Cañon City, Colorado. Known as the Garden Park quarry, this site also produced the Stegosaurus, Camptosaurus, and Ceratosaurus on display at NMNH. Although the Smithsonian obtained the Allosaurus with the rest of the Marsh Collection around 1900, Gilmore did not look at it (or any of the theropod material) until at least 1911. All told, USNM 4734 consists of a partial skull and jaw, a complete set of presacral and sacral vertebrae, a few ribs, a pelvis, and virtually complete arms and legs. It would have had a tail as well, but Mudge’s crew accidentally threw the articulated tail over a cliff while excavating the skeleton. Norman Boss assembled a reconstructed skull, which was displayed through the 1970s. The articulated legs and feet were exhibited in a free-standing case until the late 1950s.

Allosaurus skull as reconstructed by Norman Boss. Image from Gilmore 1920.

This specimen’s taxonomic history merits some discussion. The holotype Marsh selected when naming Allosaurus (YPM 1930) is notoriously poor, consisting of a single phalanx, two dorsal centra, and a tooth. Dozens of very complete skeletons attributed to Allosaurus are now known, and most specialists basically agree on what an Allosaurus is, but the lack of a usable type with which to define the taxon has been an ongoing problem.

The far more complete USNM 4734 was recovered from the same quarry as the Allosaurus holotype, during the same 1877 field season. Marsh himself actually used this specimen, rather than his designated type, to illustrate subsequent publications on Allosaurus. In 1920, Gilmore flirted with the idea of nominating USNM 4734 as a neotype for Allosaurus, but for reasons that I find difficult to follow, he decided to lump both specimens into the older name Antrodemus valens. Joseph Leidy coined Antrodemus in 1870 based on a single caudal vertebra with no geologic provenance, so this move did little to fix the underlying issue. Nevertheless, Antrodemus remained a popular synonym for Allosaurus in some circles for several decades.

Arnold Lewis rebuilds the Allosaurus skull in 1979. Image from Thomson 1985.

When the NMNH fossil halls were renovated in 1981, the designers noticed that the exhibit badly needed a large theropod mount. Arnold Lewis was tapped to design and construct a complete mounted version of USNM 4734, with some assistance from Ken Carpenter. The tail was cast from a Brigham Young University specimen, but Lewis sculpted the belly ribs and sternum using an alligator skeleton as reference. The completed Allosaurus measures 17 feet from its grinning jaws to the tip of its tail, and a form-hugging armature makes it look particularly dynamic. This mount has been a favorite among visitors for more than 30 years, although the 2001 addition of a Stan the Tyrannosaurus cast has somewhat overshadowed the smaller theropod.

The complete Allosaurus skeleton was finally exhibited in 1981. Photo by the author.

Technicians from Research Casting International took down the Allosaurus in the summer of 2014 as part of the current round of renovations. You can watch a video of the de-installation here. The skeleton will be remounted in a few years (crouching beside a nest mound), but Smithsonian researchers want to get a good look at it before that happens. In particular, curator Matt Carrano has been wondering for some time whether a partial jaw Marsh named “Labrosaurus ferox” actually belongs to this specimen. The “Labrosaurus” jaw, which has an unusual pathology caused by a bite or twisting force, came from the same quarry as USNM 4734, and appears to be the same portion of jaw that the more complete skeleton is missing. Time will tell whether Carrano’s hunch is correct. Meanwhile, Carpenter and Paul’s petition to replace the Allosaurus type with this more complete specimen from the same locality is still pending. We should expect to hear more about that soon, as well.

References

Carpenter, K., Madsen, J.H., and Lewis, L. (1994). Mounting of Fossil Vertebrate Skeletons. Vertebrate Paleontological Techniques. 285-322.

Gilmore, C. M. (1915). Osteology of Thescelosaurus, an ornithopodus dinosaur from the Lance Formation of Wyoming. Proceedings of the U.S. National Museum 49:2127:591–616.

Gilmore, C.M. (1920). Osteology of the Carnivorous Dinosauria in the United States National Museum with Special Reference to the Genera Antrodemus (Allosaurus) and Ceratosaurus. United States National Museum Bulletin 110:1-154.

Lee, J.J. (2014). The Smithsonian Disassembles its Dinosaurs. National Geographic Online. http://news.nationalgeographic.com/news/2014/07/140731-dinosaur-hall-smithsonian-renovation-culture-science/

Paul, G.S. and Carpenter, K. (2010). Allosaurus Marsh, 1877 (Dinosauria, Theropoda): proposed conservation of usage by designation of a neotype for its type species Allosaurus fragilis Marsh, 1877. Bulletin of Zoological Nomenclature 67:1:53-56.

Thomson, P. (1985). Auks, Rocks, and the Odd Dinosaur: Inside Stories from the Smithsonian’s Museum of Natural History. New York, NY: Thomas Y. Crowell.

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Filed under dinosaurs, exhibits, Extinct Monsters, fossil mounts, museums, NMNH, ornithopods, theropods

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

April 28, 2015 · 3:06 pm

Permo-Triassic Synapsids at NMNH

Click here to start the NMNH series from the beginning.

In the middle decades of the 20th century, museum theory and paleontological science were undergoing complementary revolutions. Museum workers shrugged off their “cabinet of curiosity” roots and embraced visitor-centric, education-oriented exhibits. Designers began to envision the routes visitors would travel through an exhibit space, and consider how objects on display could contribute to holistic stories. Meanwhile, paleontologists like Stephen J. Gould and David Raup moved their field away from purely descriptive natural history, exploring instead how the fossil record could inform our understanding of evolution and ecology. The common thread between both transitions was a focus on connections – bringing new meaning and relevance to disparate parts by placing them in a common narrative.

Between 1953 and 1963, the Smithsonian implemented an institution-wide modernization program, transforming virtually every exhibit in the museum complex. The National Museum of Natural History began renovations to its classic fossil halls in 1959, and the new exhibits were emblematic of contemporary trends in both museum design and paleontology. The plan, as devised by exhibit designer Ann Karras, was to do away with the loose arrangement of specimens and turn the east wing into a guided narrative of the biological and geological history of Earth. Responsibility for selecting specimens and writing label copy in each of the four halls fell to a different curator. In Hall 2, which housed dinosaurs and fossil reptiles, that curator was Nicholas Hotton.

Layout of the USNM east wing, circa 1963.

Layout of the NMNH east wing as of 1963.

Hotton joined NMNH in 1959 as an Associate Curator of Paleontology. Entirely onboard with Karras’s vision and the paleobiology movement as a whole, Hotton described the old exhibits as “crowded” and “unorganized.” He thought NMNH had plenty of dinosaurs, but “mammal-like reptiles”* were sorely needed if Hall 2 was to tell the complete story of amniote evolution. Following that, Hotton’s mission over the next several years was to assemble a respectable collection of synapsid specimens for NMNH, and to incorporate them into a well-illustrated exhibit on the origins of mammals. This post highlights just a few of the specimens featured in Hotton’s version of Hall 2.

*In Hotton’s day, early mammalian relatives were usually called “mammal-like reptiles”, hence their inclusion in the fossil reptile exhibit. Today, most specialists prefer a more precise definition of reptiles that excludes synapsid (mammal-line) animals. In this post, I will be using the modern classification wherever possible.

The Dimetrodon

Prior to 1960, the non-mammalian synapsid collections at NMNH were mostly limited to early Permian pelycosaurs. The most impressive of these was a Dimetrodon gigas collected in 1917 by independent fossil hunter Charles Sternberg. One of the best collectors of his day, Sternberg worked intermittently for E.D. Cope, O.C. Marsh, and various North American museums. In the summer of 1917, however, Sternberg was on a personal collecting trip with his son Levi. Their target was the Craddock Ranch bone bed of Baylor County, Texas, which was first explored in 1909 by a University of Chicago team. Sternberg was already quite familiar with this part of western Texas, having made some of the first thorough surveys of the Permian “red beds” in the 1880s, but the site itself was new to him. Nevertheless, Sternberg was extraordinarily successful that summer, collecting hundreds of fossils from a wide range of animals. He offered this bounty to the Smithsonian, and they purchased it from him immediately.

The Craddock Ranch fossils were particularly appealing because of their unique preservation. Buried in soft clay at the bottom of a shallow pond, the fossils could be removed from the ground with relative ease, and were largely free of encrusting matrix. Although few of the bones were articulated, many were identifiable. All told, the Sternberg collection included at least 35 skulls and partial skeletons from amphibians like Cardiocephalus, Diplocaulus, and Seymouria, plus hundreds of individual Dimetrodon bones, and a single articulated Dimetrodon specimen.

An early photograph of the Dimetrodon mount. Image from Gilmore 1919.

The Dimetrodon was first displayed on the north wall of the Hall of Extinct Monsters. Source

That Dimetrodon (USNM 8635) was the basis for a mount constructed by T.J. Horne. The articulated skeleton included a complete series of presacral vertebrae, the shoulder girdles, most of the forelimbs, and the left femur and tibia. The skull and jaw bones were found disarticulated, but bound together in the same mass of matrix as the skeleton. Horne added the pelvic bones and sacrum from smaller Dimetrodon specimens, and sculpted the rest of the missing material in plaster to complete the mount. Notably, his reconstructed tail was extremely short and stubby. Although the American Museum and Field Museum already had Dimetrodon mounts on display, the NMNH version stood out because of its open jaws, which Charles Gilmore said “gives the animal an appearance of angrily defying one who has suddenly blocked his path.”

Gilmore added the Dimetrodon to the Hall of Extinct Monsters in 1918. Like the other standing mounts constructed under Gilmore’s supervision, the skeleton was placed on a base textured and painted to resemble the rocks in which it was found. At this point in time, the NMNH fossil halls lacked any overarching organizational scheme, and interpretive content was minimal. Nevertheless, Gilmore displayed the Dimetrodon mount with both a small model and a 15-foot oil painting by Garnet Jex, which provided general audiences a better understanding of the animal’s life appearance.

Dimetrodon in the 1963 fossil reptiles exhibit. Image courtesy of the Smithsonian Institution Archives.

Dimetrodon in 2014. Photo by the author.

Dimetrodon after the 1981 renovation. Photo by the author.

During the 1962 renovation, Hotton re-contextualized the classic Dimetrodon mount as a mammal ancestor. Unmissable orange arrows pointed to the specific anatomical traits that signify the animal’s kinship with mammals, including heterodont teeth and a single temporal fenestra. By design, visitors would pass Dimetrodon before visiting the true mammals in the adjacent hall.

The Dimetrodon skeleton itself was altered during the next renovation in 1981, when it was placed on a new, untextured base and given a longer replica tail. Contemporary staff also repainted the plaster sections to more closely resemble the original fossils – a surprising reversal of Gilmore and Horne’s original intention to make the reconstructed bones obvious to viewers.

The Thrinaxodon

Pelycosaurs like Dimetrodon represent the first major synapsid radiation, but by the middle Permian they were almost entirely replaced by therapsids. A more derived group which includes modern mammals, therapsids spread across the globe and became increasingly diverse as the Permian progressed. From weasel-sized burrowers to multi-ton herbivores, non-mammalian therapsids were among the first animal groups to conquer a wide range of terrestrial niches. Hotton wanted to tell this story in the modernized fossil exhibit, but there were hardly any non-mammalian therapsids in the NMNH collections. To correct this problem, Hotton took to the field for several months in 1960, and again in 1961. He joined James Kitching in exploring the Beafort Group rocks of South Africa, which were known to produce plentiful Permian and Triassic vertebrate fossils. Hotton returned to the museum with over 200 new specimens, the best of which were used in the renovated exhibit.

Hotton’s display of South African synapsids and amphibians. Note “Baby Doll” on the far left. Photo courtesy of the Smithsonian Institution Archives.

Thrinaxodon paired with Cynognathus skull. Photo by the author.

Hotton’s most prized find from South Africa was a gorgeously preserved and nearly complete Thrinaxodon liorhinus (USNM 22812). Hotton called this specimen “Baby Doll”, and while it was not prepared in time for Hall 2’s 1963 opening, it would later earn a spot of honor in the exhibit. Before that happened, though, Baby Doll was actually stolen by an over-enthusiastic volunteer. The FBI located and returned the fossil a year and a half later.

Since the 1980s, the Thrinaxodon has been displayed alongside the skull of Cynognathus crateronotus (USNM 22813), which Hotton collected on the same expedition. Both are members of the cynodont clade, which includes some of the closest relatives of modern mammals.

The Daptocephalus

Less than a month after hall 2 reopened, Nicholas Hotton returned to South Africa. This time, he was accompanied by his spouse Ruth Hotton and their three young children. For seven months, the Hottons traveled among fossil sites on different ranches, camping most nights. They collected some 300 specimens for the Smithsonian, and Hotton’s biostratigraphic mapping of the Beaufort Group brought a measure of clarity to this region’s historically convoluted geology.

Ruth Hotton made one of the trip’s most impressive finds while prospecting in a dry riverbed with her daughter, Carol (who is now a paleobotanist at NMNH). Turning a corner, she stumbled upon a dicynodont skeleton, completely exposed and lying in the middle of the channel. One can only imagine the surprise and delight of finding an articulated fossil skeleton completely uncovered. If the Hottons had been there one season earlier or one season later, the river would have undoubtedly destroyed the fossils.

Daptocephalus on display. Photo by James Di Loreto, National Museum of Natural History.

Back at the museum, Nicholas Hotton prepared the specimen (USNM 299746) and determined it to be Daplocephalus leoniceps, one of the plethora of dicynodonts known from the Beaufort Group. Based on this classification, he reconstructed the damaged skull to resemble more complete Daplocephalus specimens, and added casts of Daplocephalus limbs.

The specimen was restored in 2019 and is now labeled Platypodosaurus. Photo by the author.

As it turns out, however, USNM 299749 is not a Daplocephalus—it is a somewhat distantly related dicynodont currently called Platypodosaurus. To varying degrees, fossil mounts are hypotheses made of bone and plaster. They are based on the best information available at the time, but sometimes they need to be corrected. The NMNH “Daplocephalus” had been mislabeled and erroneously reconstructed for many years, but the 2014 renovation of the NMNH fossil halls now presented an opportunity to deconstruct the specimen and study it up close. As of 2019, Platypodosaurus was back on display with a newly reconstructed skull and limbs.

Thanks to Christian Kammerer for kindly sharing images and insight on “Daptocephalus”!

References

Gilmore, C.W. (1919). A Mounted Skeleton of Dimetrodon gigas in the United States National Museum, with Notes on the Skeletal Anatomy. Proceedings of the United States National Museum 56:2300:525-539.

Kammerer, C. (2015). Personal communication.

Lay, M. (2013). Major Activities of the Division of Vertebrate Paleontology During the 1960s. http://paleobiology.si.edu/history/lay1960s.html

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

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

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

Tagged as evolution, fossil mounts, history of science, museums, natural history museums, paleontology, Smithsonian, synapsids

December 23, 2014 · 2:01 pm

So long, Diplodocus

USNM 10865 in the Hall of Extinct Monsters, circa 1932. Photo courtesy of the Smithsonian Institution Archives.

USNM 10865, shortly after its introduction in 1931. Photo courtesy of the Smithsonian Institution Archives.

Since the National Museum of Natural History fossil halls closed for renovation this past April, I’ve made a habit of checking the webcam in Hall 2 every couple weeks or so. For a while, it didn’t look like much was happening – the first waves of de-installation occurred out of view, toward the back of the gallery. Eventually, however, the iconic dinosaur mounts started coming down. The Allosaurus vanished in mid-July. The Stegosaurus and Camptosaurus were gone in September. By late October, the exhibit team had started cutting back the elevated platform and surrounding walkway where most of the standing dinosaur mounts had stood. This was when the process got really interesting, because previous renovations to this space over the past century have always been additive. Old exhibit panels were boarded over and forgotten decades ago, and even some elements of the 1911 Hall of Extinct Monsters, such as the John Elliot fresco “Diana of the Tides”, are still buried in these walls. To hear about these time capsules of science history being unsealed over the past few months has been absolutely thrilling.

But when I checked the webcam last Tuesday, I was met with a slight sinking feeling. The Diplodocus, the centerpiece of this hall for the last 83 years, was gone.

Hall 2 at NMNH, as of December 23, 2014. Source

After it was excavated from Dinosaur National Monument in 1923, USNM 10865 took Charles Gilmore, Norman Boss, Thomas Horne, and John Barrett nearly a decade to prepare and mount. Aside from an an adjustment to the neck supports in the early 80s (making it hang from the ceiling, rather than being propped up from the floor), the Diplodocus remained in place and unmodified for longer than the average American lifespan. Generations of visitors have gazed up at it, and those lucky enough to view it before 1963 were able to walk under it. This mount has unquestionably taken on a second life: it is an institutional and regional icon as much as it is a dinosaur that once roamed a Jurassic floodplain. And in three days, NMNH collections staff and specialists from Research Casting International cleared every trace of it – well over 200 individual bones – from the hall.

The Diplodocus, as it stood from 1963 through 1981. Image courtesy of the Smithsonian Institution Archives.

The Diplodocus, as seen from 1963 through 1981. Image courtesy of the Smithsonian Institution Archives.

I can’t help but feel a twinge of sadness to see the Diplodocus go. I’ve been visiting the sauropod since before I could talk. I knew it as a toddler, as a high school volunteer, as a fresh-out-of college-intern, and as a museum professional. Even though the fossil halls have been closed for months, I suppose it was comforting to know that the Diplodocus was still standing on the other side of those barriers. But now it’s actually gone, and that makes it really sink in that the NMNH fossil hall that I knew – the one that inspired and nurtured my life-long interest in paleontology, is gone for good.

An early sketch of USNM 10865’s new home – anchoring the Jurassic ecosystem display.

Of course, the now-disarticulated Diplodocus fossils are in the best possible hands. The veteran team at RCI will conserve, restore, and eventually remount them in a stunning, dynamic pose. What’s more, the renovated fossil hall in which it will be reintroduced is going to be awesome – structurally, aesthetically, and pedagogically. It will contextualize classic specimens like the Diplodocus within a modern understanding of how the ancient past is connected to our present and future, while simultaneously honoring this space’s history and heritage. I can’t wait.

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Filed under dinosaurs, exhibits, fossil mounts, history of science, museums, NMNH, sauropods

Tagged as dinosaurs, diplodocus, fossil mounts, history of science, museums, NMNH, paleontology, Smithsonian

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

May 18, 2014 · 3:44 pm

Extinct Monsters Updated

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

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

Extinct Monsters: Brachyceratops

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

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

The Brachyceratops mount today. Photo by the author.

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

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

Reconstruction of Brachyceratops holotype skull. Plate from Gilmore 1917.

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

A helpful breakdown of the Brachyceratops mount from Gilmore 1922.

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

Norman Boss Brachyceratops courtesy Smithsonian archives

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

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

Brachyceratops on exhibit with Triceratops. Plate from Gilmore 1922.

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

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

References

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

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

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

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

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

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

August 6, 2013 · 7:52 pm

The Gilmore Models: Where are they now?

Regular readers of this site (if there are any) undoubtedly know Charles Whitney Gilmore as the Smithsonian paleontologist who, between 1903 and 1964, led in the creation of most of the mounted dinosaur skeletons that remain on display at the National Museum of Natural History today. You don’t necessarily have to be in Washington, DC to see Gilmore’s reconstructions, however. In addition to being an expert anatomist and fossil preparator, Gilmore was a formidable sculptor, and during his tenure at the Smithsonian he produced a number of gorgeous life reconstructions of prehistoric animals. Plaster copies of these models were gifted or sold to large and small museums in North America and Europe, including the Sternberg Museum of Natural History, the University of Kansas Natural History Museum and the Hunterian Museum at the University of Glasgow. These models were typically displayed alongside isolated fossil elements to give a sense of the entire animal at institutions where complete mounts were unfeasible.

Charles Gilmore, or Chucky G, as he was known to his friends.

Unfortunately, many of the museums that acquired copies of Gilmore’s models in the 1920s and 30s seem to have lost the detailed provenance of these acquisitions (not a rare occurrence, as museums must track literally millions of objects and historic records on paper do not always survive). The Hunterian Museum has the best records regarding these models that I am aware of, and incidentally their online catalog is the source of most of the photographs in this post.

Stegosaurus model in plaster of paris. Image courtesy of the Hunterian Museum and Art Gallery.

While Gilmore’s models are obviously far from accurate by modern standards, a closer inspection reveals that Gilmore was familiar with every inch of the fossils in his care, and put that knowledge to use in his sculptures. The Stegosaurus above, for instance, is a perfect match for Gilmore’s full-sized mount in terms of pose and proportion. Undoubtedly, physically assembling an actual skeleton is among the best ways to become familiar with how an animal would work in three dimensions. In particular, note that unlike many contemporary reconstructions, Gilmore did not fudge the number or position of the plates; they’re all accounted for.

Triceratops model in plaster of paris. Image courtesy of the Hunterian Museum and Art Gallery.

The Triceratops model exhibits a number of interesting choices. The classic bowed ceratopsian forelimbs (which Gilmore first proposed after finding no other way to articulate them in his 1905 Triceratops mount) are clearly in evidence, but my eye is drawn to the scrawny, lizard-like hindlimbs. Comparing this model to Gilmore’s mount, there would appear to be virtually no muscle back there. The size of the head is yet another remnant of the mounting process. Since his Triceratops mount was a composite of numerous specimens, Gilmore used the skull of an inappropriately small animal, and apparently carried the chimeric proportions to this sculpture. The lack of cheeks and extremely thick neck are also characteristic of older ceratopsian reconstructions, although I can’t comment on precisely when or why that look went out of style.

Diplodocus model in plaster of paris. Image courtesy of the Hunterian Museum and Art Gallery.

This Diplodocus has a much more defined shape than most mid-century sauropod reconstructions. Note in particular the sloping back, which peaks at the sacrum. This differs from the 1907 Diplodocus mount at the Carnegie Museum of Natural History, which had a completely horizontal spinal column. When Gilmore led the creation of the Smithsonian Diplodocus mount, he had the opportunity to use a vertebral column that was found articulated in situ, and was thus able to more accurately portray the shape of the animal’s midsection.

Ceratosaurus. Image courtesy of the Hunterian Museum and Art Gallery.

Gilmore’s Ceratosaurus is the liveliest of the set, and is the only one that doesn’t strictly adhere to the pose of a corresponding fossil mount. Delivering a killing blow to a hapless ornithopod, one can easily imagine the energetic pounce that preceded this scene. I will point out, though, that this guy’s hindquarters are enormous.

Gilmore's stub-tailed Dimetrodon. Image from Gilmore 1939.

Gilmore’s stub-tailed Dimetrodon model.

Gilmore also sculpted some non-dinosaurs, including at least one prehistoric horse and the Dimetrodon pictured above. Note the teensy stub of a tail, which this model actually shared with Gilmore’s mount of the pelycosaur. The lips obscuring most of the teeth except for a couple incisors is an unusual choice, and I’m not sure what inspired it. This image is from Gilmore’s 1939 paper on Dimetrodon, and the Basiliscus basiliscus in the corner provides a helpful comparison to a contemporary animal with a similar dorsal sail.

In addition to the models shown here, Gilmore created sculptures of “Anatosaurus”, “Brachyceratops” and a Cenozoic horse, as well as busts of Styracosaurus and Corythosaurus (and there may well have been others I haven’t seen). As mentioned, copies of these mounts were distributed to museums and possibly private collections throughout the 20s and 30s, and I have no idea how many were actually made. A few museums, such as the Sternberg Museum, actually have these models on display, but at other institutions they have been relegated to storage. Objects like these present an unusual challenge for collections managers. They were accessioned as scientific representations, but their value has shifted over the last century to the realm of art and history. While these models are undoubtedly important, they are probably no longer useful at many of the institutions that hold them. As such, the Gilmore models exemplify that museum collections are not necessarily static, but change in meaning as the years go by.

If you work at an institution that has one or more Gilmore models in its collection, feel free to leave a comment. I’d love to start a working database of where copies of these models have ended up!

References

Gilmore, C.W. (1939). “A Mounted Skeleton of Dimetrodon gigas in the United States National Museum, with Notes on the Skeletal Anatomy.” Proceedings of the US National Museum 56:2300:525-539.

Gilmore, C.W. (1932) “On a newly mounted skeleton of Diplodocus in the United States National Museum.” Proceedings of the United States National Museum 81:1-21.

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Tagged as dinosaurs, Gilmore, museums, natural history museums, NMNH, Smithsonian

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