Category Archives: history of science

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.

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

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

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.

Note basilo

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

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

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

Hatcher, Stan, and the Changing Identities of Fossil Mounts

Photo by the author

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

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

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

The First Triceratops

Hatcher in Hall of Extinct Monsters

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

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

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

Hatcher in Sunday star

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

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

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

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

Hatcher_tempdisplay

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

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

A Prefab Tyrannosaurus?

Stan. Photo by Chip Clark.

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

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

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

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

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

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

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

Reassembling Stan upstairs. Photo by Abby Telfer.

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

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

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

Bully for Camarasaurus

Note: This post was written in 2014. It predates Emanuel Tschopp’s landmark paper which, among other things, resurrected the genus “Brontosaurus.” I’ve attempted to update the taxonomy where appropriate, but it may still be a bit of a mess.

The story of the mismatched head of Brontosaurus is one of the best known tales from the history of paleontology. I think I first heard it while watching my tattered VHS copy of More Dinosaurs – scientists had mistakenly mounted the skull of Camarasaurus on an Apatosaurus skeleton, and the error went unnoticed for decades. The legend has been repeated countless times, perhaps because we revel in the idea that even experts can make silly mistakes. Nevertheless, I think it’s time we set the record straight: nobody ever mistakenly placed a Camarasaurus skull on Apatosaurus. The truth is a lot more nuanced – and a lot more interesting – than a simple case of mistaken identity.

Intrinsically related to the head-swap story is the replacement of “Brontosaurus” with “Apatosaurus” in the popular lexicon. This is well covered elsewhere, so I’ll be brief. Scientific names for animals are governed by the International Code of Zoological Nomenclature, which includes the principle of priority: if an organism has been given more than one name, the oldest published name is the correct one. Leading 19th century paleontologist O.C. Marsh named Apatosaurus ajax in 1877, based on a vertebral column discovered in the Morrison Formation of Colorado. Two years later, Marsh introduced Brontosaurus excelsus to the world, from a more complete specimen uncovered in rocks of the same age in Wyoming. Like many of Marsh’s publications, these descriptions were extremely brief, offering a scant two paragraphs for each taxon. However, Marsh did provide a longer description of Brontosaurus in 1883, complete with the first-ever restoration of the complete skeleton.

This is not a Camarasaurus skull.

Come play with us, Brontosaurus…forever and ever and ever. Photo courtesy of the AMNH Research Library.

In 1903, Elmer Riggs of the Field Museum of Natural History underwent a survey of sauropod fossils held at various east coast museums and concluded that Brontosaurus excelsus was too similar to Apatosaurus to merit its own genus. The name “Brontosaurus” was dropped, and the species became Apatosaurus excelsus for most of the 20th century. However, a substantial re-evaluation of diplodocoid sauropods by Emanuel Tschopp and colleagues in 2015 reversed Riggs’ decision. So the name Brontosaurus is back, but keep in mind that the species excelsus never actually went anywhere – it was just hidden under the Apatosaurus umbrella. Following Tschopp et al., Apatosaurus and Brontosaurus were distinct animals that lived in the same environment.

So how does the mismatched head fit into all of this? The short answer is that it doesn’t. The fact that some Apatosaurus mounts had incorrect heads for much of the 20th century has nothing to do with which name was being used at any given time, although the two issues have often been conflated in popular books. I suspect the two stories got mixed up because paleontologists were pushing to correct both misconceptions around the same time during the dinosaur renaissance.

Marsh's Brontosaurus

Marsh’s second and definitive Brontosaurus reconstruction, first published in 1891.

Let’s go back to Marsh’s 1891 Brontosaurus reconstruction*, pictured above. The Brontosaurus type specimen did not include a head, and many have reported that Marsh used a Camarasaurus skull in this illustration. However, this would not have been possible, because the first complete Camarasaurus skull wasn’t discovered until 1899. What Marsh had instead were a few fragmentary bits of Camarasaurus cranial material, plus a snout and jaw (USNM 5730) now thought to be Brachiosaurus (more on this at SV-POW). Although these pieces were found far from the Brontosaurus quarry, Marsh extrapolated from them to create the best-guess skull that appears in his published reconstruction.

*Note that this is the second of two “Brontosaurus” reconstructions commissioned by Marsh. The first drawing, published in 1883, has somewhat different skull, but it still does not resemble Camarasaurus. 

Although the venerable Stephen Gould states in his classic essay “Bully for Brontosaurus” that Marsh mounted the Brontosaurus holotype at the Yale Peabody Museum, Marsh never saw his most famous dinosaur assembled in three dimensions. In fact, Marsh strongly disliked the idea of mounting fossil skeletons, considering it a trivial endeavor of no benefit to science. Instead, it was Adam Hermann of the American Museum of Natural History, supervised by Henry Osborn, who built the original Brontosaurus/Apatosaurus mount (AMNH 460), six years after Marsh’s death in 1899.

Counterclockwise from top:

Clockwise from top: AMNH sculpted skull (Source), Peabody Museum sculpted skull, real Apatosaurus skull (Source), and real Camarasaurus skull.

To create the mounted skeleton Hermann combined fossil material from four separate individuals. All of the material had been collected by AMNH teams in Wyoming specifically for a display mount  – and to beat Andrew Carnegie at building the first mounted sauropod. Like Marsh, however, they failed to find an associated skull (a Camarasaurus-like tooth was allegedly found near the primary specimen, but it has since been lost). Even today, sauropod skulls are notoriously rare, perhaps because they are quick to fall off and roll away during decomposition. Instead, Hermann was forced to sculpt a stand-in skull in plaster. Osborn explained in an associated publication that this model skull was “largely conjectural and based on that of Morosaurus” (Morosaurus was a competing name for Camarasaurus that is no longer used).

Was it really, though? The sculpted skull is charmingly crude, so the overt differences between the model and a real Camarasaurus skull (top and bottom left in the image above) might be attributed to the simplicity of the model. Note that there isn’t even an open space between the upper and lower jaws! Still, Hermann’s model bears a striking resemblance to Marsh’s illustration in certain details, principally the elongate snout and the very large, ovoid orbit. It certainly isn’t out of the question that Hermann used Marsh’s speculative drawing as a reference, in addition to any actual Camarasaurus material that was available to him. At the very least, it is incorrect to say that AMNH staff mistakenly gave the mount a Camarasaurus skull, since Osborn openly states that it is a “conjectural” model.

A young Mark Norell

A young Mark Norell leads the removal of the sculpted skull from the classic AMNH Apatosaurus. Source

In 1909, a team led by Earl Douglass  of the Carnegie Museum of Natural History finally discovered a real Apatosaurus skull (third image, lower right). They were working at the eastern Utah quarry that is now Dinosaur National Monument, excavating the most complete Apatosaurus skeleton yet found (CM 3018). The skull in question (cataloged as CM 11162) was not connected to the skeleton, but Douglass had little doubt that they belonged together. Back at the Carnegie Museum, director William Holland all but confirmed this when he found that the skull fit neatly with the skeleton’s first cervical vertebra. As he wrote at the time, “this confirms…that Marsh’s Brontosaurus skull is a myth.”

The Carnegie team prepared and mounted the new Apatosaurus, and Holland initially planned to use the associated skull. However, when Osborn heard about this he threatened to ruin Holland’s career if he went through with it. You see, the new skull looked nothing like the round, pseudo-Camarasaurus model skull on the AMNH mount. Instead, it was flat and broad, like a more robust version of Diplodocus. Osborn wasn’t about to let Holland contradict his museum’s star attraction, and Holland backed down, never completing his planned publication on the true nature of Apatosaurus. Meanwhile, the mounted skeleton at the Carnegie Museum remained headless until Holland’s death in 1932. After that, museum staff quietly added a Camarasaurus-like skull. This was an important event, as it would be the first time an actual casted skull of Camarasaurus (as opposed to a freehand sculpture) would be attached to a mounted Apatosaurus skeleton. While I’ve had no luck determining precisely who was involved, Keith Parsons speculated that the decision was made primarily for aesthetic reasons.

Carnegie Museum Brontosaurus circa 1934. Source

Carnegie Museum Apatosaurus alongside the famed Diplodocus, sometime after 1934. Source

Elmer Riggs assembled a third Apatosaurus mount (FMNH P25112) at the Field Museum in 1908. Riggs had recovered the articulated and nearly complete back end of the sauropod near Fruita, Colorado in 1901, but was unable to secure funding for further collecting trips to complete the mount. Riggs was forced to mount his half Apatosaurus as-is, and the absurd display stood teetering on its back legs for 50 years. Finally, Riggs’ successor Orville Gilpin acquired enough Apatosaurus fossils to complete the mount in 1958. As usual, no head was available, so Gilpin followed the Carnegie Museum’s lead and gave the mount a casted Camarasaurus skull.

The completed mount as it stood in the 1970s, Camarasaurus head and all.

Orville Gilpin finally completed the FMNH Apatosaurus in 1958.

The last classic apatosaurine mount was built at the Yale Peabody Museum of Natural History in 1931, using Marsh’s original Brontosaurus excelsus holotype (YPM 1980) and a lot of plaster padding. The skull this mount originally sported (third image, upper right) is undoubtedly the strangest of the lot. A plaster replica sculpted around a small portion of a real Camarasaurus mandible, this model doesn’t look like any known sauropod. The overall shape is much more elongated than either Camarasaurus or the AMNH model, and may have been inspired by Marsh’s hypothetical illustration. Other details, however, are completely new. The anteorbital fenestrae are thin horizontal slashes, rather than the wide openings in previous reconstructions, while the tiny, forward-leaning nares don’t look like any dinosaur skull – real or imaginary – I’ve ever seen. The sculptor is sadly unknown, but this model almost looks like a committee-assembled combination of the Marsh drawing, the AMNH model, and CM 11162 (a.k.a. the real Apatosaurus skull).

During the mid-20th century, vertebrate paleontology lapsed into a quiet period. Although the aging dinosaur displays at American museums remained popular with the public, these animals came to be perceived as evolutionary dead-ends, of little interest to the majority of scientists. The controversies surrounding old mounts were largely forgotten, even among specialists, and museum visitors saw no reason not to accept these reconstructions (museums are, after all, one of the most trusted sources of information around).

A postcard

The Peabody Brontosaurus with its original head. Note that the Camarasaurus in the foreground also has a sculpted skull.

This changed with the onset of the dinosaur renaissance in the 1970s and 80s, which brought renewed energy to the discipline in the wake of new evidence that dinosaurs had been energetic and socially sophisticated animals. In the midst of this revolution, John McIntosh of Wesleyan University re-identified the real skull of Apatosaurus. Along with David Berman, McIntosh studied the archived notes of Marsh, Douglass, and Holland and tracked down the various specimens on which reconstructed skulls had been based. They determined that Marsh’s restoration of the Brontosaurus skull, long accepted as dogma, had in fact been almost entirely arbitrary. Following the trail of guesswork, misunderstandings, and scientific inertia, McIntosh and Berman proved that Holland had been right all along. The skull recovered at Dinosaur National Monument along with the Carnegie Apatosaurus was in fact the only legitimate skull ever found from this animal. In 1981, McIntosh himself replaced the head of the Peabody Museum Brontosaurus with a cast of the Carnegie skull. AMNH, the Field Museum, and the Carnegie Museum followed suit before the decade was out.

aess

Remounted Apatosaurus at the Carnegie Museum. Photo by the author.

Given the small size of the historic community of dinosaur specialists, it may have been particularly vulnerable to the influences of a few charismatic individuals. To wit, Marsh’s speculative Brontosaurus skull was widely accepted despite a lack of compelling evidence, and Osborn was apparently able to bully Holland out of publishing a find that contradicted the mount at AMNH. What’s more, the legend of the mismatched Brontosaurus skull somehow became distorted by the idea that either Marsh or Osborn had accidentally given their reconstructions the head of Camarasaurus. This is marginally true at best, since both men actually oversaw the creation of composite reconstructions which only passingly resembled Camarasaurus. Nevertheless, the idea that the skull of Camarasaurus was a passable substitute for that of Apatosaurus was apparently well-established by the 1930s, when Carnegie staff hybridized the two sauropods for the first time. Even today, there are numerous conflicting versions of this story, and it is difficult to sort out which details are historically accurate and which are merely assumed.

I’d like to close by pointing out that while the head-swap story is often recounted as a scientific gaffe, it is really an example of science working as it should. Although it took a few decades, the mistakes of the past were overcome by sound evidence. Despite powerful social and political influences, evidence and reason eventually won out, demonstrating the self-corrective power of the scientific process.

References

Berman, D.S. and McIntosh, J.S. 1975. Description of the Palate and Lower Jaw of the Sauropod Dinosaur Diplodocus with Remarks on the Nature of the Skull of ApatosaurusJournal of Paleontology 49:1:187-199.

Brinkman, P. 2006. Bully for Apatosaurus. Endeavour 30:4:126-130.

Gould, S.J. 1991. Bully for Brontosaurus: Reflections in Natural History. New York, NY: W.W. Norton and Company.

Osborn, H.F. 1905. Skull and Skeleton of the Sauropodous Dinosaurs, Morosaurus and BrontosaurusScience 22:560:374-376.

Parsons, K.M. 1997. The Wrongheaded Dinosaur. Carnegie Magazine. November/December:38.

Tschopp, E., Mateus, O., and Benson, R.B.J. 2015. A specimen-level phylogenetic analysis and taxonomic revision of Diplodocidae (Dinosauria, Sauropoda). PeerJ 3:e857. https://doi.org/10.7717/peerj.857

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Spinosaurus at the National Geographic Museum

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Research Casting International has done it again with a beautiful reconstructed skeleton of a swimming Spinosaurus. Photo by the author.

Yesterday, Nizar Ibrahim and National Geographic made a tremendous splash with their long-awaited announcement of a new Spinosaurus specimen. Spinosaurus is a widely recognized and beloved dinosaur (particularly among what one might call the dinosaur fandom community), but paradoxically it is known from only the scrappiest of fossil remains. What’s more, the holotype specimen is long gone – destroyed in the bombing of Munich during World War II. No doubt the enigmatic nature of Spinosaurus is a major part of its appeal. At any rate, the new paper by Ibrahim and colleagues describes the never-before-seen hindlimbs and pelvis of Spinosaurus, and proposes that the dinosaur’s anatomy – and behavior – were far more extreme than previously assumed. The new specimen reveals that Spinosaurus had narrow hips and legs barely longer than its arms. This was not an animal built for running on land, and a quadrupedal posture is not out of the question. What’s more, Spinosaurus limb bones are surprisingly dense for a theropod, not unlike the heavy bones of seals and early whales. Ibrahim and colleagues paint a picture of Spinosaurus as an animal that was at least as at-home in the water as it was on land.

The news has provoked the usual cycle of rampant speculation among dino fans, dismissal of sensationalism by some professionals, and even well-reasoned, evidence-based criticism. After the fervor dies down, we can assess whether this hypothesis holds water. In the meantime, though, I must applaud the tremendously impressive show National Geographic has put on. As part of the media roll-out that started yesterday afternoon, National Geographic has prepared both a television special and a traveling exhibit revolving around Spinosaurus. Some might scoff at all the hype over a partial skeleton, but I’d call this science outreach at its best, put on by some of the most experienced folks in the business.

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This Spinosaurus sculpture will be a fixture outside the National Geographic Building on 17th street until January. Photo by the author.

“Spinosaurus: Lost Giant of the Cretaceous” opened this morning at the National Geographic Explorer’s Hall in Washington, DC, and in this post I’d like to share my initial impressions. Visitors approaching from M Street are greeted by a life-sized Spinosaurus sculpture, posed over a half-eaten fish. This superb model was produced by the Italian studio GeoModel, and was apparently over a year in the making. Conceptual art and behind-the-scenes photos can be seen here. I’m not sure if the model has quite the extreme proportions that are proposed in the paper, but it’s not like I actually measured it. Regardless, this is a stunning piece  that will be a DC fixture through the end of the year.

The shrine to Ernst Stromer at the exhibit's entrance. Photo by the author.

The shrine to Ernst Stromer at the exhibit’s entrance. Photo by the author.

Once you’ve gone inside and paid your admission (I remember when this museum was free…oh well), you can enter the Spinosaurus exhibit proper. Interestingly, the exhibit is framed not as a science lesson but as a historical account. The first objects on display are documents and other possessions of Ernst Stromer, the German paleontologist who originally described Spinosaurus in 1915. Passing through a narrow corridor, you’ll see a reconstruction of the Spinosaurus holotype as it was displayed at the Bavarian State Collection in Munich, a Moroccan fossil shop, and even a replica of the cave where a Mysterious Bedouin Stranger led Ibrahim to the new find. Each stop is supplemented by a video mixing talking-head interviews with somewhat silly re-enactments of historic events. I particularly liked Stromer being berated by his Nazi boss.

Reconstruction of the holotype

I never dreamed I’d ever see an exact reconstruction of the Spinosaurus holotype, which was destroyed during World War II. Photo by the author.

I thought this method of storytelling was quite clever. By focusing on the role of Spinosaurus in world history, the exhibit can grab the attention of adult visitors that would usually dismiss dinosaurs as kids’ stuff. National Geographic’s shtick has always been presenting stories of intrepid scientists on adventures in distant locales, and there is plenty of that in evidence here. This sort of exoticism is probably a little problematic, but the gorgeous images of the Moroccan desert were clearly having the desired effect on some of my fellow visitors. Usually, I would complain about the over-reliance on long videos, but people seemed to be watching them all the way to the end, so I guess I’ll keep quiet this time.

Spinosaurus!

Spinosaurus in all its glory. Photo by the author.

Once the history lesson is over, the exhibit opens up into a larger display space. This is similar to what was done in “The World’s Largest Dinosaurs” – a narrow entry gallery introduces visitors to the topic at hand and the central questions being discussed, then visitors are freed to look at what they find interesting in whatever order they choose. All in all, this layout is a good compromise between the need to convey a specific educational message and the need to let visitors make the exhibit experience their own.

The star of the show is of course the reconstructed skeleton of Spinosaurus, yet another fantastic display piece by Research Casting International. Check out a time-lapse video of the mount being assembled here. What wasn’t clear from the grainy preview images that were flying around the internet a couple months ago is that the Spinosaurus is actually in a swimming pose. Its legs are posed in mid-paddle, and its head is turned to the right to snag a model sawfish. Above all, the mount is big. So big, in fact, that I couldn’t find anywhere in the gallery where I could photograph it all at once. I’d love to see this thing alongside Sue.

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The process of 3D printing digital fossils, explained. Photo by the author.

Happily, the exhibit takes the time to acknowledge that the Spinosaurus mount is not only a cast, but a composite of many fossil specimens. There is even a small display showcasing the process by which fossils are scanned and 3-D printed at a consistent scale. It’s great that the exhibit explains the evidence that led to the aquatic Spinosaurus reconstruction, showcasing the process of making and testing a scientific hypothesis.

Around the perimeter of the Spinosaurus gallery are displays of the other paleofauna of the Kem Kem region in Morocco, which Paul Sereno and company have been assembling for many years. There are models of azdarchid pterosaurs and coelocanth fish, as well as a Deltadromeus skeleton and skulls of  Carcharodontosaurus and Rugops (all heavily-reconstructed casts). All of these displays explore the question of how so many carnivores could co-exist in one environment. The answer provided is that each predator was specialized to hunt a different kind of prey: Spinosaurus chased fish, Carcharodontosaurus ate big herbivorous dinosaurs and (this will undoubtedly annoy some) Rugops is presented as an obligate scavenger.

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Some Kem Kem friends: Deltadromeus and Carcharodontosaurus. Photo by the author.

I have virtually nothing negative to say about the Spinosaurus exhibit. This is a great story, well told, and I was thoroughly impressed by nearly every part of it. The only thing that might be a sore point for some is that there are very few authentic fossils on display. A single dorsal spine is the only real bone representing Spinosaurus. Nevertheless, the exhibit team has shown precisely how to dramatize the process of scientific discovery, while still making the process transparent and relateable. Bravo.

 

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

Hello new followers!

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

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

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

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

A Primer on Fossil Mounts

Museums and the Triceratops Posture Problem – Parts One and Two

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

The Osborn Problem

History of Fossil Displays at the Smithsonian

The Calvert Marine Museum’s Big Foam Shark

Juan Bautista Bru and the First Fossil Mount

First Full-Sized Dinosaurs: From Crystal Palace to Hadrosaurus

Chicago’s Half-Finished Sauropod

In Defense of New Museums

Beating the Orthogenetic Horse

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Museums and the Triceratops Posture Problem – Part 2

Triceratops at the National Museum of Natural History.

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

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

The Hatcher Project

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

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

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A rendering of the digital Hatcher. Source

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

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

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

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

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

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

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

Houston and Los Angeles Mounts

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

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

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

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

"Lane" at Houston Museum

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

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

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

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

References

Chapman, R. Personal communication.

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

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

Hunt-Foster, R. Personal communication.

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

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