Category Archives: reviews

What’s the deal with Astrodon?

In Laurel, Maryland, a trail of banners depicting a herd of the sauropod dinosaur Astrodon johnstoni leads the way to Dinosaur Park, the site of a historically significant fossil deposit. At the Maryland Science Center in Baltimore, a life-sized Astrodon sculpture towers over the “Dinosaur Mysteries” exhibit. And since 1998, Astrodon has been the official state dinosaur of Maryland, joining other state symbols like the black-eyed susan and Baltimore oriole. In short, Astrodon is a sort of mascot for mid-Atlantic paleontology. Named in 1858 for fossils found in a Prince George’s County iron mine, the appeal of Astrodon for Marylanders is obvious: it’s a home-grown dinosaur in a region that is not widely recognized for its fossil resources, and the story of its discovery also calls attention to the state’s industrial heritage.

But what sort of animal was Astrodon, and how much do paleontologists truly know about it? Compared to many other extinct animals found around the world, the fossil record for Astrodon is and always has been fairly poor. The name Astrodon was first bestowed upon nothing more than isolated teeth, and although other fragmentary remains attributed to Astrodon have been uncovered over the past 150 years, reconstructions of the Maryland sauropod are mostly derived from the fossils of relatives found elsewhere. What’s more, the name Astrodon has a convoluted history, having been applied haphazardly to fossils found across the country and even around the world. For these reasons, some paleontologists would prefer that the name Astrodon not be used at all.

Lacking a scientific consensus on what sort of animal the Maryland sauropod was or even what it should be called, I find myself in a difficult position as an educator. How can the messy and contentious taxonomy of Astrodon be condensed into something teachable? Is simplifying or downplaying this controversy doing our audience a disservice, and to what degree?

The taxonomic history of Astrodon

The first scientifically recognized North American dinosaur fossils were found in the Mid-Atlantic region, a scant 17 years after dinosaurs were first recognized as a biological group in 1842. Joseph Leidy’s Hadrosaurus from the New Jersey coast is credited as the first American dinosaur to be described, but Astrodon was a close second. During the mid-19th century, iron mining was big business in central Maryland. Miners extracted large boulders of siderite, or iron ore, from open pit mines throughout Prince George’s County, and these miners were the first in the region to discover dinosaur bones and teeth. The siderite was being mined from clay deposits now known as the Arundel Formation, part of the larger Potomac Group that extends throughout Maryland (the Potomac Group was laid down during the Early Cretaceous period, between 125 and 113 million years ago). Members of the Maryland Academy of Sciences recognized the fossils from the Arundel clay as similar to the English fossil reptiles that Richard Owen had recently unified as Dinosauria. In 1858, academy member Christopher Johnston published a description of a set of teeth from the iron mines in the American Journal of Dental Science, which he named “Astrodon” (Joseph Leidy turned this informal name into a proper binomial, Astrodon johnstoni, in his 1865 review of North American fossil reptiles).

Today, most paleontologists consider it poor judgment to name a new taxon based only on teeth. When scientists describe a newly discovered organism, they designate a type specimen, which is used to define that taxon in perpetuity. But when the type specimen is especially fragmentary, or only consists of a small part of the organism, it poses a problem for future researchers. In the case of Astrodon, no newly discovered fossils other than teeth can be confidently referred to the same species. In 1858, however, paleontological norms were very different. All dinosaur fossils known at the time were exceedingly incomplete: scientists knew that dinosaurs were reptiles and that they were very big and not much else. Any new fossils, even teeth, represented a major addition to our understanding of the life appearance and diversity of these extinct animals. For modern paleontologists, Johnston’s published description of the Astrodon teeth is vague and uninformative, but in his day, these fossils were distinct from anything else yet known.

Astrodon teeth lower left.

Astrodon teeth are on the lower left.

In December of 1887, famed paleontologist Othneil Charles Marsh sent his best fossil hunter, John Bell Hatcher, to search the area in Prince George’s County where Astrodon was discovered. Judging from Hatcher’s journal entries, he didn’t have a great time. It rained and snowed almost constantly, and on several days his team didn’t bother to show up for work. Although Hatcher managed to find numerous dinosaur, crocodile and turtle fossils, these finds did not match the quality of the fossils Hatcher had been finding in the western states, and no return trips were made. Nevertheless, Marsh saw fit to name two new dinosaur species from the material Hatcher collected: Pluerocoelus altus and Pluerocoelus nanus. Neither taxon was named for material that would be considered diagnostic if found today: P. altus was based on a tibia and fibula, while P. nanus was based on four nonadjacent vertebrae.

By this time, more complete dinosaur fossils from the American west were beginning to reveal a clearer picture of dinosaur diversity. Based on the shape and size of the fossils collected by Hatcher, Marsh determined that they belonged to sauropods, the group of long-necked herbivores that includes Diplodocus and Apatosaurus. More specifically, Marsh recognized that the Arundel sauropods were similar to “Morosaurus” (now called Camarasaurus) from Colorado. Today, the lineage of stocky, broad-nosed sauropods that includes Camarasaurus and its closest relatives are called macronarians. Unfortunately, by modern standards Marsh’s descriptions of P. altus and P. nanus are rudimentary in nature, and no distinguishing characteristics not common to all macronarian sauropods were offered.

Pleurocoelus elements. Image from NMNH Backyard Dinosaurs.

Pleurocoelus (or Astrodon?) fossils collected by Hatcher. Image from NMNH online exhibit Backyard Dinosaurs.

Contra Marsh, Hatcher suspected that there was only one sauropod in the Arundel Formation. P. altus and P. nanus were probably growth stages of one species, and the Astrodon teeth, now recognized as typical of macronarians, probably came from the same animal, as well. Since the International Code of Zoological Nomenclature decrees that the first published name given to a taxon has priority, Astrodon would take precedence over Pluerocoelus. Later, Charles Gilmore published a review of the Arundel fossils, in which he concurred with Hatcher that P. altus was a junior synonym of Astrodon, but retained P. nanus as a separate species.  

Then things started getting really complicated. While paleontologists were still debating how many sauropod species existed in the Arundel clay, Marsh and others had started naming lots of new species of Pluerocoelus. Fossils found in Texas, Oklahoma and even the U.K. were all thrown into the Pluerocoelus bucket, including P. montanusP. valdensisP. becklesii and P. suffosus. For much of the 20th century, Pluerocoelus was a classic wastebasket taxon, into which any and all sauropod fossils from early Cretaceous strata were casually thrown. Since the Pluerocoelus type specimens designated by Marsh were insufficient to define the taxon based on morphology, the name became little more than a temporal marker. Adding to the confusion, researchers continued to disagree over whether all these new Pluerocoelus species should be sunk into the earlier genus Astrodon.

In recent years, some progress has been made toward untangling this mess of early Cretaceous sauropods. There is a general consensus that fossils not found in Maryland’s Potomac Group differ substantially from the Arundel sauropods and should never have been referred to Pluerocoelus or Astrodon. New names have been proposed for the midwestern sauropods, including Astrophocaudia and Paluxysaurus. However, removing the non-Maryland fossils from the discussion merely returns us to the original set of problems: how many sauropods are represented in the Arundel clay, what were they like in life, and what should we call them?

Creating a coherent picture of Astrodon

Unfortunately, the answers to these questions depend on who you ask. The most thorough review of Arundel sauropods from the last decade was published by Kenneth Carpenter and Virginia Tidwell in 2005. Carpenter and Tidwell reaffirmed Hatcher’s conclusion that Pluerocoelus is synonymous with Astrodon, and that as the earliest published name, Astrodon has priority. This decision is apparently based only on the fact that the fossils came from the same stratum, however, since the Astrodon holotype cannot be compared to anything besides other teeth. For this reason, Michael D’Emic proposed in 2012 that the names Astrodon and Pluerocoelus are nomen dubia and should both be dropped entirely. Ultimately, neither solution is practical for identifying the sauropod fossils that continue to be collected from the Arundel Formation. Either we blindly refer any and all sauropod fossils to Astrodon, even though we lack a usable holotype, or we have no label available at all.  One solution would be to establish a new type specimen (called a neotype) for Astrodon, but this has yet to be done.

Both camarasaur and brachiosaur shaped Astrodon reconstructions are equally reasonable.

Both camarasaur and brachiosaur-shaped Astrodon reconstructions are reasonable. Artwork by Dmitry Bogdanov, via Wikipedia.

While many more sauropod fossils have been found in the Arundel clay since Hatcher’s 1887 expedition, we do not have enough material to fully elucidate what these animals looked like. Size estimates have varied enormously, from as little as 30 feet to as much as 80 feet in length. The assortment of fossil bones and teeth that have been found tell us we have a macronarian sauropod, and we can reconstruct its general shape based on more completely known relatives. However, macronarians were a fairly diverse bunch, ranging from the comparatively stocky camarasaurs to high-shouldered, elongate brachiosaurs. Carpenter and Tidwell describe the Arundel sauropod fossils, particularly the limb bones, as being fairly slender, but still more robust than those of Brachiosaurus. They do recognize, however, that nearly all known Arundel sauropod fossils come from juveniles, which may vary proportionally from adults. Because the precise affinities of Astrodon are unclear, artistic reconstructions vary substantially. The National Museum of Natural History’s Backyard Dinosaurs exhibit and website shows a camarasaur-shaped sauropod, while the life-sized sculpture at the Maryland Science Center is based on the brachiosaur Giraffatitan. At Dinosaur Park in Laurel, meanwhile, both versions are on display. More fossils, ideally cervical vertebrae or more complete adult material, are needed to clarify what the Arundel sauropod looked really like.

Teaching Astrodon

When I show people the teeth and partial bones attributed to Astrodon during public programs, I am almost always asked, “if that’s all you’ve found, how do you know what the whole animal looked like?”  As demonstrated by this post, it takes 1,700 words and counting to give a proper answer, which is too much for all but the most dedicated audiences. Nevertheless, to do anything less is to skip crucial caveats and information. Scientists are choosy about the words they use, filling explanations with “probablys” and “almost certainlys”, but they do so with good reason: when one’s job is to create and communicate knowledge, there is no room for ambiguity about what is and is not known. It is therefore just a bit dishonest to say that a large sauropod called Astrodon that was related to Brachiosaurus lived in Maryland, and yet I do so every week. How can I possibly sleep at night?

I’ll admit it can be difficult, but I get by because using one proviso-free name for the Maryland sauropod seems to be  informative and helpful to my audience. I only have people’s attention for so long, and I’d rather not spend that time on tangents about how Astrodon should really be called Pluerocoelus or why my use of either name is imprecise and problematic. I want visitors to walk away understanding how paleontologists assemble clues from sedimentary structures and anatomical comparisons to reconstruct ancient environments and their inhabitants. I’d like for visitors to practice making observations and drawing conclusions, and understand how paleontology is a meticulous science that can be relevant to their lives. “Paleontologists are weirdly obsessed with changing names” is not one of the most important things to know about paleontology.

Taxonomy, the science of naming and identifying living things, is unquestionably valuable. Biologists would be lost without the ability to differentiate among taxa. From my perspective, however, the public face of paleontology tends to overemphasize taxonomic debates in lieu of more informative discussions. There will always be somebody willing to argue whether Tarbosaurus bataar should be sunk into Tyrannosaurus, or to give incorrect explanations for why we lost “Brontosaurus.” In the end, though, these debates have more to do with people’s preferences than the actual biology of these animals. Astrodon may not be a diagnostic taxon in the strictest sense, but we need to call our fossils something, and taxonomic labels exist to be informative and useful. If asked, I’m always happy to provide the full story. But for the time being, Astrodon seems to be working just fine.


Carpenter, K. and Tidwell, V. 2005. Reassessment of the Early Cretaceous sauropod Astrodon johnstoni Leidy 1865 (Titanosauriformes). In Carpenter and Tidwell (eds.), Thunder-Lizards: The Sauropodomorph Dinosaurs. Bloomington, IA: Indiana University Press.

D’Emic M.D. 2012. Revision of the sauropod dinosaurs of the Lower Cretaceous Trinity Group, southern USA, with the description of a new genus. Journal of Systematic Paleontology, iFirst 2012, 1-20.

Gilmore, C.W. 1921. The fauna of the Arundel Formation of Maryland. Proceedings of the United States National Museum. 59: 581-594.

Kranz, P.M. Dinosaurs in Maryland. 1989. Published by Maryland Geological Survey, Department of Natural Resources, Educational Series No. 6.

Marsh, O.C. 1888. Notice of a New Genus of Sauropoda and Other New Dinosaurs from the Potomac Formation.

Please note that the usual disclaimer applies: views or opinions expressed here are mine, and do not reflect any institution with which I am affiliated.

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Filed under citizen science, Dinosaur Park, dinosaurs, field work, history of science, reviews, sauropods, systematics

Review: Ultimate Dinosaurs at the Cincinnati Museum Center

Ultimate Dinosaurs: Giants from Gondwana premiered in June 2012 with considerable fanfare at the Royal Ontario Museum (ROM) in Toronto. Developed by a ROM team led by David Evans and Matthew Vavrek, Ultimate Dinosaurs showcased the dinosaurs of the southern hemisphere, demonstrating how geographic isolation created Mesozoic ecosystems remarkably different from the menageries we are used to seeing in North American museum displays. The exhibit included 20 dinosaur mounts in all, including many taxa never before seen in museums above the equator.

I never made it to the inaugural showing of Ultimate Dinosaurs, but fortunately the show is now on the road. I saw it at the Cincinnati Museum Center (CMC) earlier this week, where it will remain through January 5th before moving on to Minneapolis. The exhibit assuredly does not disappoint…read on for many pictures and my musings on the design.


The first room features Triassic and early Jurassic archosaurs.

Huge banners displayed outside the CMC and in the main lobby are impossible to miss, but the Ultimate Dinosaurs exhibit itself is hidden away on the lower level, with the entrance at the end of a quiet corridor. Aside from a video screen showing a shifting map of Gondwana, no proper introduction is provided. Visitors immediately find themselves in the first large room of fossil mounts, featuring Triassic and early Jurassic archosaurs like Herrerasaurus, Eoraptor, Cryolophosaurus and the rauisuchian Prestosuchus. This first batch of mounts is lined up on an elevated platform that runs along the right side of the room. Like all the mounts in Ultimate Dinosaurs, these are casts, and are plainly assembled in “chunks”: numerous bone elements casted together as single pieces. While these shortcuts are obvious up close, this mode of construction does allow for remarkably dynamic poses, and there is no obstructive armature to block one’s view. Behind the dinosaurs is the first of several gorgeous Julius Csotonyi murals, a lively panorama of life reconstructions in a naturalistic setting.

In front of every mount is an array of attractive signs in bright, solid colors. Information is mostly provided in short sound bites or bullet points, highlighting sensible information like the animal’s diet, the meaning of its name, where it was discovered, and why it is scientifically noteworthy. There is also at least one touchscreen in front of each mount, which includes several more pages of information for the more dedicated visitor. I really liked the similar touchscreen displays at the Carnegie Museum, and these are equally impressive. This is technology used intelligently, contributing to but not overwhelming the primary display, while using space in an economical way. I was also impressed by the succinctness of the text. It is very difficult to condense information into short blurbs that visitors can absorb with no more than a quick glance, but the Ultimate Dinosaurs writers balanced accuracy, intrigue and brevity on every single sign. Hats off to them!

Visitors were having a hell of a time pronouncing Cryolophosaurus.

Visitors were having a hell of a time pronouncing Cryolophosaurus.

Turning left at the Massospondylus at the far end of the first room, visitors enter a long and largely empty corridor. The left wall is adorned with a series of signs explaining the historical discovery of and evidence for continental drift, and herein lies my primary concern with the exhibit as a whole. The story being told in Ultimate Dinosaurs, regarding plate tectonics and its effect on evolution, is an important one. Paleobiogeography is key to understanding how the natural world we know today came to be. What’s more, it’s a great example of science in action, consisting of a handful of intuitive, evidence-based concepts that can be applied to new situations and clarify new discoveries.  As such, paleobiogeography ought to frame the entire exhibit. I would have placed the big ideas and central questions (Why are similar organisms sometimes found on opposite sides of oceans? What happens when populations or ecosystems are isolated from one another?) at the beginning, and ensured that they were reinforced in every display with recurring terms, imagery and motifs. The paleobiogeography story should guide the visitor’s experience and understanding of the exhibit.

Instead, Ultimate Dinosaurs at the CMC relegates the big ideas to secluded corners and easily-missed signs. The text itself is very clear and well-written, and supported by attractive, intuitive graphics, but it’s hidden away and or otherwise overshadowed by lists of factoids about each dinosaur. My largely unsubstantiated suspicion is that the original designers of Ultimate Dinosaurs at the ROM intended for the paleobiogeography story to be much more explicit, but this vision was compromised somewhat in order to fit the exhibit into the space available at the CMC. The unfortunate result is that the most critical information is introduced in an unorganized manner, and the exhibit is weaker for it.

Suchomimus peers in from the right, Amargasaurus and

Suchomimus peers in from the right, Malawisaurus in the middle, Argentina in back.

After passing through the switchbacking corridor, visitors reach the primary showroom. This is an enormous space filled with huge, impressive dinosaur mounts. Like the rest of the exhibit, this gallery is quite dark, with floor lights and the occasional overhead light highlighting the dinosaurs. The darkness helps to hide the unadorned walls and ceilings of the multipurpose space being used, but thankfully does not hinder one’s view of the dinosaurs. And the dinosaurs certainly do not disappoint. Even though they are casts, this exhibit was my first opportunity to see the likes of Armagasaurus, Suchomimus, Ouranosaurus and many others in person. I could walk around them, take in their scale and compare them to one another and to myself, experiences that no image or documentary can provide.

Majungasaurus and Rapetosaurus strike an extreme pose.

Majungasaurus and Rapetosaurus strike an extreme pose.

Most of the dinosaurs are in lively poses, as though the animal was frozen midstride, but a few are especially dynamic. Little Rahonavis is suspended from the ceiling, as though leaping for prey or perhaps engaging in a controlled glide to the forest floor. The Majungasaurus and Rapetosaurus, which are the only mounts directly interacting with one another, are particularly interesting. The attacking Majungasaurus has its foot up on the flank of the Rapetosaurus, and the sauropod is in a rather unusual squatting pose, with its forelimbs at what appears to be maximum flexion. I will leave it to the experts to decide whether this extreme pose is plausible, but this nevertheless serves as a reminder of what can be learned by assembling a skeleton in three-dimensional space.


Carnotaurus and Amargasaurus.

The mounts are clustered on three islands, representing Argentina, Madagascar and Niger. I do wish this organization had been made clearer to visitors, perhaps with large banners over the islands naming the dinosaurs’ location of origin. Clustered at the feet of the mounts are small cases containing a mix of original and casted fossils. Some of those are quite relevant and provide further context to the mounts: for instance, a collection of North African fossil fish near the Suchomimus illustrate the spinosaur’s probable diet. Other cases are a bit more perplexing. A series of cervical vertebrae from the North American sauropod Suuwassea is arbitrarily situated among the Madagascar mounts, and cases of cephalopods and Carboniferous plants are similarly out of place. Most of these oddball fossil displays did not come from the ROM, but were added by the CMC from their own collections. Although these fossils are fascinating and should absolutely be on display, I don’t think randomly interjecting them among the Gondwanan dinosaurs was the way to go. These displays interrupt the primary storyline and probably should have been placed elsewhere.

CWC addition

These additions from the CMC are neat, but a bit out of place.

The final room showcases the exhibit’s two largest mounts, Tyrannosaurus and Giganotosaurus. It is undeniably exciting to see these two giant predators side by side, and compare how these ostensibly similar carnivores were nevertheless subtly adapted to tackle different prey. I would have made this point more obvious than the exhibit does, but I suppose sometimes you need to step back and let your specimens speak for themselves.

This room also features the much-ballyhooed “augmented reality” gimmick. These are tablet-sized screens found alongside the mounts. When you point these at the Tyrannosaurus and Giganotosaurus skeletons, a CG version of dinosaur appears on the screen. Panning and tilting the tablet in front of the mount causes your view of the CG version to adjust accordingly. I found these sort of interesting, but they were not nearly as impressive as the mounts themselves. Unfortunately, the CG dinosaurs simply didn’t look very good. I am all for the use of technology in museum exhibits, but only if it plays to our strengths. In this case, the CG dinosaurs are directly and unfavorably comparable to a wide range of films and television shows that people can see without leaving home. As hubs for lifetime learning, museums can and should offer more than that.

Tyrannosaurus and Giganotosaurus side by side. Eat it up, internet.

Tyrannosaurus and Giganotosaurus side by side. Eat it up, internet.

Despite my nitpicks, Ultimate Dinosaurs really does live up to its name. This is a very handsomely designed exhibit, and an great opportunity to see mounts of exotic dinosaur taxa. If you are at all interested in paleontology, catching this exhibit is a no-brainer. But even if you’re not, this is a rare chance to see what the vertebrate fossil record has to offer beyond T. rex and Triceratops, and learn a bit about how our world came to be.

Edit: I had mistakenly said the murals were created by Raul Martin. They are the work of Julius Csotonyi.


Filed under dinosaurs, exhibits, fossil mounts, museums, ornithopods, reptiles, reviews, sauropods, theropods

A Visit to the Academy of Natural Sciences

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

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

Original 1868 Hadrosaurus mount.

Original 1868 Hadrosaurus mount.

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

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

What’s Cool

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

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

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

What’s Not So Cool

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

Corythosaurus and Chasmosaurus mounts. Source: TravelMuse.

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

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

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

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

Their hands were everywhere: the Morrison Natural History Museum

Outside the Morrison Natural History Museum. Doesn’t look like much…

Last week, I had a fantastic experience at the Morrison Natural History Museum, a little gem tucked away in the tiny town of Morrison, Colorado, on the north side of Denver. Since its opening in 1985, the Museum has served as a local educational resource covering the region’s plentiful paleontological resources. According to its website, the Museum is primarily a teaching institution. An affiliated foundation raises funds to bring local students on field trips, in support of the Museum’s mission to nurture “an understanding of and respect for the deep past.” In keeping with this teaching institution, gentle touching of all the fossils and casts is encouraged. This policy, and the design choices that go with it, are what truly set the Morrison Museum exhibits apart.

Paleontologically-inclined people are of course familiar with the Morrison Formation, the sequence of Upper Jurassic beds that extends across much of the western United States. The formation, which extends some 600,000 square miles, was named for the town of Morrison, where fossils were first discovered in 1877. The Morrison formation is probably best known as the epicenter of the “bone wars” between Othniel Charles Marsh and Edward Drinker Cope, who each led competing teams of fossil hunters across the region, attempting to best one another’s discoveries. Marsh and Cope were affiliated with the Peabody Museum in New Haven and the Academy of Natural Sciences in Philadelphia, respectively, so the fossils they collected all ended up back east. Indeed, while the Morrison region is among the most important and productive places for finding dinosaurs in the country, comparatively few of the treasures found there have remained in the region. The Morrison Natural History Museum therefore exists, at least in part, as a dedicated local repository and interpretative center for the region’s natural history.

The 1st floor Jurassic exhibit.

The Museum’s exhibit space is tiny, only 2000 square feet, but it is chock full of awesome. The exhibition consists of three main rooms, each one representing a geological time period. In the first floor Jurassic gallery, highlights include partial casts of Allosaurus and Apatosaurus,  the holotype of Stegosaurus, trackways attributed to Stegosaurus and a baby sauropod, and some original 19th century lithographic prints from Marsh’s monographs. For those interested in the history of paleontology, and of science in general, those prints are particularly fascinating.

Infant sauropod trackway with model of probable trackmaker.

Cretaceous and Cenozoic exhibits are found on the second floor. Most of the objects here are casts, most notably full skeletons of Platycarpus and Pteranodon, and skulls of Triceratops, Tylosaurus and a Columbian Mammoth. There are also a number of live animals on display, including a very charismatic monitor lizard thoughtfully placed next to its close relatives, the mosasaurs.

Original 19th century lithograph prints of fossil illustrations by Marsh’s team.

The signs and labels in the exhibit are noteworthy for their succinctness and clarity. It can be extremely challenging for writers of museum copy to provide appropriate depth of content without confusing, boring or alienating audiences with too much text. Overlong and unfocused labels are particularly common in small museums, where most of the copy is written by a single curator bent on sharing everything he or she knows about a topic. On the other end of the spectrum, larger, committee-designed exhibit labels can be too brief, too simple and too narrowly focused on the exhibit’s educational goals to be of much use to anybody. Happily, the Morrison Museum avoids both of these pitfalls. Labels are simple and attractive, but still informative and up-to-date. I was rather impressed by the economical way in which they addressed the most important topics in paleontology.

An example of a brief but content-rich label.

Obviously, the fossils and other objects on display are fantastic, and many, like the trackways, are quite unique. However, as mentioned above, one of the most remarkable aspects of the Museum is that touching of all the fossils and casts is encouraged.  Few objects are behind glass; everything is out in the open for people to touch and examine up close. There are many in the museum field who would be horrified by such an arrangement. When putting objects on exhibit, it is a given that they are considered consumable. No matter what precautions are taken, anything put on display will inevitably suffer damage. Of course, the flip side is that exhibit designers want to allow visitors to get as close to the objects as possible. The Morrison Museum has taken this to the extreme. The fossils, many one them irreplaceable holotype specimens, are fully exposed to accidental or intentional abuse by visitors. This is a very bold move on the part of the Museum, and it makes the point that the knowledge visitors can gain from full access to objects is more valuable that the objects themselves.

I won’t lie, my initial reaction upon seeing this exhibit layout was open-mouthed horror. But after spending some time in the space, I think the Morrison Museum may be on to something. This is a great way to tap into the multiple intelligences of visitors. Obviously, this system only works because the Museum’s attendance is on the low side (I would hate to see what the summer hordes at NMNH or AMNH would do if they were allowed to run wild among the mounts),  but given these circumstances I think the open-access approach is a great educational tool.

Overall, I was very pleased with my visit to the Morrison Museum. The volunteer staff knowledgable, passionate and helpful, the exhibits were excellent, and the handful of other visitors passing through (mostly young children) seemed genuinely engaged. The Museum is well worth a stop for anyone in the Denver area, and may well be a worthwhile model for other museums to follow.


Filed under dinosaurs, mammals, museums, paleoart, reptiles, reviews, science communication

The World’s Largest Dinosaurs (AMNH Part 1)

I spent the weekend in New York, and was able to spend a full day at the American Museum of Natural History. I’m a fan of New York, it’s just brimming with culture and has a neighborliness that one doesn’t see many other places. It had been much too long since I had been there, and even longer since I had been to AMNH. There’s a fair bit of brain dumping I’d like to accomplish on the topic of the museum, so I’ll probably  be posting thoughts on the  permanent paleobiology galleries and the mobile app fairly soon. For now, however, I really need to take a moment to gush about The World’s Largest Dinosaurs.

A typical dinosaur exhibit is based on the spectacle of the mounted skeletons. The curtain is raised on the strange and spectacularly large dinosaur bones, everybody oohs and ahhs, and that is all most/many visitors get out of it. Moreover, people leave (and probably came in with) the impression that paleontologists are people who dig up dinosaur bones and then put them on display. Such is not the case with The World’s Largest Dinosaurs, a new temporary exhibit at AMNH.

Life-size Mamenchisaurus. From

The World’s Largest Dinosaurs is unique because it is not focused on skeletal mounts. There are no mounts to speak of in the gallery, and in fact, there are very few fossils on display at all. This exhibit provides a window into what vertebrate paleontologists do after they dig up the bones. Specifically, it is about sauropod biology. There has been a lot of really fascinating research into sauropod biology in the last 10-15 years, asking and answering questions such as, how did they carry all that weight? How did they reproduce? How did they get enough to eat? And of course, what’s the deal with those pneumatic bones? These questions are all explored in this exhibit.

A crappy image of an interactive display.

The layout of The World’s Largest Dinosaurs is very effective. Visitors are oriented in a narrow space that clearly lays out the topic at hand. Using skeletons of modern animals as comparisons, the questions that the very existence of sauropods raise are introduced to visitors (i.e., how did they get away with being so effin big?). Once the question is laid out, the exhibit opens up into a large space with many stations that address different research questions. The “ooh and ahh” factor is covered by a life-size model of a Mamenchisaurus in the center of the gallery, which doubles as a projection screen: animations of the circulatory, respritory and reproductive systems are displayed right on the model, accompanied by narration (see below).

Mamenchisaurus projection screen. From

I was at AMNH on what turned out to be a very crowded day (no surprise, it was a rainy day on a holiday weekend), but I managed to get into the day’s earliest time slot, before it got too packed. When I was there at least, it was quiet enough for people to see the exhibits, and to get ahold of the interactives. As such, I observed people around me engaging with and understanding the material. Kids were working through the problems presented in the exhibit, despite the attempts of their parents to dumb down their experience and herd them through faster. The non-paleo people I were interested enough to read just about everything. Importantly, I heard no complaints that there weren’t many fossils on display. This is interesting, given how vocal some museum visitors can be about the exhibition of casts. Evidently, The World’s Largest Dinosaurs succeeded in entertaining and educating people without traditional mounted skeletons. I think this could potentially be a very big deal, and could cause museums to rethink the way paleontology exhibits are designed.

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Filed under AMNH, dinosaurs, museums, reviews, science communication