Dr. Advait Jukar – Solving Mysteries in South Asian Fossil Communities

Dr. Advait Jukar–Deep Time – Peter Buck Fellow at the Smithsonian Institute–wants to really understand ancient ecosystems in South Asia, but doing so means beginning with some of the very basics. Challenges include not just a lack of available fossils from the region, but also the lack of detailed records from early paleontologists and a dearth of contemporary research.

He is, in a sense, an explorer.  (All paleontologists are.)  If we think of paleontology as a sculpture in progress, many scientists are working on the fine details.  Dr. Jukar, on the other hand, has the clay and the tools, but the sculpture itself hasn’t even begun to take form.

Consider what he has to work with: isolated proboscidean teeth and skulls, for example, collected by Hugh Falconer and his crew in the early 1800s.  They didn’t record where the bones were found, let alone where each fossil was in relation to the other.  Those who later described these fossils made dubious claims regarding the species.  And few people to this day have revisited this data or expanded upon it. 

 

Image of Dr. Advait Jukar at work with an Elephas hysudricus molar; courtesy of Dr. Jukar

 

Compare this to Maiasaura fossils in the Northwest US.  So many fossils of this species have been excavated that Dr. Holly Woodward Ballard has created the Maiasaura Life History Project.  Its goal is to uncover more details about this particular species than any other currently known extinct creature.  She has a wealth of data at her disposal. Unlike Dr. Jukar, the fossils she can study have been found fairly well articulated, very well documented, and in remarkable abundance.  There are adults, sub-adults, juveniles and embryos.  She and her colleagues are able to add to existing scientific literature using the latest technology.  It’s an exciting project with absolutely fascinating possibilities.

 

FIGURE 6. Survivorship curve for Maiasaura. Sample size of 50 tibiae was standardized to an initial cohort of 1000 individuals (assumes 0% neonate mortality). Survivorship is based on the number of individuals surviving to reach age x (the end of the growth hiatus marked by LAG x). Age at death for individuals over 1 year old was determined by the number of LAGs plus growth marks within the EFS, when present. Error bars represent 95% confidence interval. Mean annual mortality rates (μ^) given for age ranges 0–1 years, 2–8 years, and 9–15 years. Vertical gray bars visually separate the three mortality rate age ranges; courtesy Dr. Woodward Ballard for this post. 

 

 

 

But so, too, is Dr. Jukar’s intended research.   Focusing on the tail end of the Neogene, about 4 million years ago, through the Quaternary, he wants to understand herbivorous mammals—their community, their ecology, their biogeography.  It’s just a question of building the necessary foundation first.

“I started to compile all of these species lists,” he explained by phone, “and saw that there were lots of species of proboscideans in South Asia during that period of time.  We have gomphotheres; we have stegodons; we have elephants.”

One way to understand an animal’s impact on its environment is to assess its body mass.  How big (or small) were these animals?  And therefore, how much did they need to eat?  A larger animal would presumably need to eat a larger amount of vegetation.  Similarly, a larger animal might reproduce less frequently than smaller animals.  Body mass reveals clues about how an animal fits into the ecosystem.

However, he continued, “I hit a wall because there was no way for me to estimate how big these elephants were.  The problem was they were largely known either from skulls or teeth, and the traditional methods to estimate the weight of an extinct elephant were using shoulder height or the length and circumference of the long bones. So if I have a skull but I don’t have long bones, I’m sort of in a bind, because now I can’t estimate how much this animal weighed when it was alive.”

He looked to methods that others have used in the past. One method used by his colleagues at Howard University seemed to be a promising fit.  They used the occipital condyle breadth of seacows—a proboscidean relative–as an indicator for body mass.  Dr. Jukar’s PhD advisor, Mark Uhen, mentioned that this method had also been used on yet another large mammal: the whale. 

The occipital condyle is a bone found at the base of the back of the skull, connecting the skull to the spinal column.  It’s a relatively small bone.  Why would this have an impact on determining body mass?

“If occipital condyle breadth is correlated with the size of the animal,” Dr. Jukar said, “and if the occipital condyle is the point where the skull attaches to the rest of the skeleton, then maybe the size of the skull scales with the size of the overall body. And if that’s true, then maybe the occipital condyle breadth will scale with the size of the limb bones as well.”

 

Image of the back of a mastodon (nicknamed ‘Max’) skull at the Western Science Center in California displaying the occipital condyle bone resting on the metal stand; photo taken by Jeanne Timmons

 

In other words, if a paleontologist has but one skull of an extinct proboscidean and no other related fossils, can that person measure the breadth of the occipital condyle as a way to determine the size and weight of that animal?

To test this theory on proboscideans, he researched available scientific literature and visited a number of museum collections.  Ultimately, he and his two co-authors, S. Kathleen Lyons and Mark Uhen, compared the occipital condyle breadth to the length and circumference of leg bones within extant elephants and extinct relatives.  Two elephant species were studied, as were six gomphotheres, three mastodons and one stegodon.  

Image of a fossil Moeritherium at the Yale Peabody Museum; photo taken by Jeanne Timmons

 

While careful to note that this method has its limitations, the results were promising.  The equations are different for each proboscidean family (gomphothere body structure and size is not the same as that of a mastodon) and they do not work for some of the smaller proboscidean species, such as Moeritherium.  In layperson’s terms, this research works for taller, lumbering proboscideans, not those with much shorter limbs and a perhaps waddling gait. Their paper and its results were published in the Zoological Journal of the Linnean Society: A cranial correlate of body mass in proboscideans.

This, though, is just the tip of the iceberg in terms of Dr. Jukar’s research.  An enormous collection of fossils from India resides in the Natural History Museum of London.  Found in an area referred to as the Siwalik Hills (or the “Siwaliks”) at the base of the Himalayas, Scottish paleontologist Hugh Falconer and his team collected them in the 1800s.  Among them are several stegodon teeth and skulls. 

Image of Dr. Advait Jukar measuring a Stegodon ganesa fossil in the Natural History Museum of London collection; courtesy of Dr. Jukar

 

The two species of stegodon excavated from the Siwaliks are, to this date, known as Stegodon insignis and Stegodon ganesa.  The species have very similar teeth, but their skulls seem to differ greatly.  The skull of S. insignis, according to Dr. Jukar, is “almost triangular in shape with relatively small tusks,” which Falconer chalked up to sexual dimorphism.

“Which I just thought was the weirdest thing to ever say about stegodons because the skulls are clearly different. They’re clearly not sexually dimorphic.”

Moreover, there seems to be confusion regarding which fossils Falconer assigned to which stegodon species that continues to this day.  

“So what was going on in his mind? I have no idea.  It’s a problem! Because since then, people have said that both of these must be the same species without really truly investigating them. 

“Any Stegodon tooth that they’re finding in the Siwaliks, they’re calling Stegodon insignis or Stegodon ganesa or a hyphenated version of the two: Stegodon insignis-ganesa, which is taxonomic heresy.” 

And here Dr. Jukar was emphatic: “You CANNOT do that with the taxonomic code.”

“And that was Osborn’s fault.”

He was referring to Henry Fairfield Osborn, former professor then curator of the American Museum of Natural History in the late 1800s.

“Osborn [is known to have asserted], ‘I agree with what Falconer said, so I’m going to hyphenate these two words.’  Which created such a mess.  So we have no idea what’s going on there. 

“There’s a lot of work to be done with elephant taxonomy, biogeography and systematics and comparisons between China, the Levant, East Africa and India.”

 

Image of the Levant (Public Domain)

 

Dr. Jukar and other colleagues have also recently published papers on the earliest known fossil of Hexaprotodon, an extinct hippo, from South Asia, and the first record of a Hippaprionine horse (Plesiohipparion huangheense) from the Indian Pliocene.

He is currently working with Dr. Adrian Lister of the Natural History Museum in London to further understand the various proboscidean fossils in the Siwalik collection.

This is important work, but Dr. Jukar pondered its reception to the wider world.

“For a long time paleontologists have been criticized as being mere stamp collectors because we find things and then we name them and then we try to figure out in what larger group they belong to.  But that is the basis of our data.

“Only when I have a comprehensive sense of what the species are, when they lived and where they lived can I start doing these more complicated community-level analyses.

“But because the basic science of naming a fossil might not be very exciting, [as it doesn’t directly impact] human life very much, it doesn’t get a lot of attention. 

“I am definitely interested in the big picture questions of dispersal from Africa into South Asia, about the ecology of these groups, about how communities have changed through time, but I can’t really do a rigorous analysis until I figure out who the [basic] players are in this place.”

Image of Dr. Advait Jukar with a Mammuthus columbi (Columbian mammoth) skull; courtesy of Dr. Jukar

 

References:

1. Colbert E. (1996). Henry Fairfield Osborn and the Proboscidea. In:  Shoshani J, Tassy P. The Proboscidea : evolution and palaeoecology of elephants and their relatives, Oxford: Oxford University Press, xxii – xxv
2. Dr. Advait Jukar’s website: https://advaitjukar.weebly.com
3. Jukar, Advait M., Lyons, S. Kathleen, Uhen, Mark D. (2018.  A cranial correlate of body mass in proboscideans, Zoological Journal of the Linnean Society, Volume 184, Issue 3, 20 October 2018, Pages 919–931, https://doi.org/10.1093/zoolinnean/zlx108
4. Jukar, Advait M., Patnaik, Rajeev, Chauhan, Parth R., Li, Hong-Chun, Lin, Jih-Pai (2019). The youngest occurrence of Hexaprotodon Falconer and Cautley, 1836 (Hippopotamidae, Mammalia) from South Asia with a discussion on its extinction, Quaternary International, January 2019, https://doi.org/10.1016/j.quaint.2019.01.005
5. Jukar, Advait Mahesh, Sun, Boyang, Bernor, Raymond Louis, (2018). The first occurrence of Plesiohipparion huangheense (Qiu, Huang & Guo, 1987) (Equidae, Hipparionini) from the late Pliocene of India,  Bollettino della Società Paleontologica Italiana; 57(2):125-132 · August 2018
6. Saegusa H. (1996). Stegodontidae: Evolutionary Relationships. In:  Shoshani J, Tassy P. The Proboscidea : evolution and palaeoecology of elephants and their relatives, Oxford: Oxford University Press, xxii – xxv

 

It was a GREAT pleasure and honor speaking with Dr. Advait Jukar.  Many, many thanks for your time, Advait, your help, your fascinating insight and your gorgeous images!! I cannot wait to read your future scientific papers!

 

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North American Proboscideans and Dr. Chris Widga – Part 1

“Most zooarchaeologists are interested in the people, and they use the animals as kind of a tool for understanding butchering patterns or food ways or something like that.”

Dr. Chris Widga and I were in the midst of a great conversation about three recent papers he co-authored, paleontology, proboscideans, and the state of science today.

“I was always interested in the animals themselves,” he continued, “so when I got the position as a vertebrate paleontologist at the [Illinois State Museum], all of my friends who’d known me for years said, ‘well, that was a no-brainer for us. You were doing vertebrate paleontology all the time on Holocene bison. You never cared much about the people!’”

That beginning in zooarchaeology and the subsequent immersion in paleontology are what give him a unique perspective of the two sciences.  Or, as he himself explained: “I guess I kind of have this foot in both worlds.”

The two occasionally overlap.  In the paper published this past February in Boreas, “Late Pleistocene proboscidean population dynamics in the North American Midcontinent,” he and his colleagues take a closer look at what might have caused the extinction of mammoths and mastodons in what is now the middle of North America. Possible culprits include climate change, shifts in available vegetation, and predators (including humans).

Of the 627 localities included in this study, only 3 offer any kind of human association.  The authors state that these sites were “re-visited to ensure consistent taphonomic and zooarchaeological data,” and that, despite this, whether or not these specific humans and proboscideans interacted remains unclear.

“That’s a distinction I like to make as a paleontologist and a zooarchaeologist,” Dr. Widga offered. “Just because we have a couple of the sites with humans associated [doesn’t necessarily indicate that] humans actually hunted, killed and butchered those animals.  [Humans] may have scavenged them.  They may just simply be associated in these sites. And very few of those sites have been analyzed to the degree of detail that we really need to start teasing apart those issues.”

What he and co-authors Stacey N. Lengyel, Jeff Saunders, Gregory Hodgins, J. Douglas Walker, and Alan D. Wanamaker try to do, however, is take a deeper look at the late Pleistocene environment in which these proboscideans lived.  It’s exciting research: Rather than simply describing fossils discovered in the various US states and one Canadian province, they are trying to put them into context.  In other words, they are trying to understand the ecology of that time period and how that may have affected the megafauna living within it.

But it’s not an easy task.

“Ecologists can look at modern ecosystems and say, ‘Ok. This is what’s going on, and this is why we think that, and this is how we’re measuring it’ in great detail.  But extrapolating those same processes back into the paleontological record is often really, really difficult even with the best data set.

For example, “[w]e can observe boom-and-bust cycles in deer populations, in caribou populations, in musk ox and things like that. But when you try and translate that into the paleontological record, most of the time it’s really difficult because you simply don’t have the samples and you don’t have the time resolution.

“Even in our case, where we have really good samples and we have really good dates on our samples and we’re creating this chronological structure to kind of fit them in, it’s really difficult to translate those patterns into ecology.

“We can’t date a single mastodon any more precisely than about a hundred-year window.”

The fact that some of the ecological constructs used today in extant populations are controversial makes trying to apply such constructs to extinct animals that much more of a challenge.

“When even the ecologists can’t truly [agree upon] what’s going on, you have to navigate things very, very carefully.”

The amount of work put into this paper (work that has produced previous, subsequent and yet-to-be-published papers) is staggering.  Thanks to a National Science Foundation grant, Dr. Widga and Dr. Jeff Saunders—both previously at the Illinois State Museum—were able to visit an astounding number of museum collections in the Midwest and review their proboscidean fossils.

“We’ve [basically] spent the last 5 years in other people’s collections,” he explained. “It was fun because we visited a lot of collections that people don’t usually go to. About half of the data set comes from repositories that have fewer than five mammoths and mastodons.”

 

 

An inside look at the extensive fossil collection at the Indiana State Museum collection–one of the many collections visited by Dr. Widga.  In our conversation, he said, “The Indiana State Museum is a big dot on the map in terms of mammoths and mastodons, in part because of [paleobiologist Ron Richards’] work!”   This image was taken in 2005, picturing then Collections Manager Michele Gretna (currently Director of Archaeology); image courtesy Indiana State Museum and Historic Sites.

Another inside look at the Indiana State Museum collection; Preparator Elizabeth Scott after the reconstruction of the Kolarik locality mastodon tusks, 2014; image courtesy Indiana State Museum and Historic Sites

 

 

Their work involved the review of over 1600 fossils that currently reside in collections in Ontario, Canada, as well as in Arkansas, Illinois, Indiana, Iowa, Kansas, Kentucky, Minnesota, Michigan, Nevada, Ohio, South Dakota and Wisconsin.

“We doubled the number of known published sites for mammoths and mastodons in the Midwest.”

Information that they are willing to share with other scientists, as evidenced by the number of papers they continue to co-author.  Following the Boreas paper, Dr. Widga was part of another two papers published in March in Quaternary International and then in Scientific Reports.

Mammoth teeth take a leading role in the paper, “Reconciling phylogenetic and morphological trends in North American Mammuthus,” published in Quaternary International and co-written with Jeff Saunders and Jacob Enk.

“We’re starting to put out some of these ideas that actually put data onto these [traditional] species boxes that we like to put specimens into.  So that was one of the first steps into thinking about these things: more as morphologically variable populations rather than just trying to assign them to a particular species.

“A lot of times these studies kind of happen in isolation.  So the people that think about morphology, they’ll publish on the morphology and then post-hoc, they’ll say, ‘oh but this doesn’t agree with the genetics at all.’ Or the geneticists will publish on the genetics, but they don’t integrate any morphology.  So our point was to try and integrate both of them and see what they say. Can you use the genetics to kind of structure your interpretations of what the morphology means?”

The authors studied “M3s”—the permanent upper 3^rd molar—of both female and male mammoths of various ages from museum collections and from previously published work.

Per Dr. Widga, this is the upper 3rd mammoth molar from Clear Lake Sand and Gravel Pit, Sangamon County, IL. One of his favorites from the ISM collection. It dates to the Last Glacial Maximum and had preserved DNA so is included in the Enk dataset; image and caption courtesy Chris Widga.

 

“Jeff [Saunders] and I would say, ‘this genetic information actually fits perfectly with our morphological information which suggests that there’s a lot of population overlap in between these normally well-defined populations.’ So in between Columbian mammoths in the Great Plains and woolly mammoths from the Great Lakes you have Iowa mammoths that show characteristics of both. And also they show characteristics of both in the same animal!

“That was kind of the impetus for the [Quaternary International paper]: to get that out there, show that you do get a lot of overlap in the morphology. It’s not just clean boxes of Columbian mammoths and woolly mammoths. And even pygmy mammoths overlap with Western Columbian mammoths! So that was kind of the point of the paper: to get the conversation going and make a first pass–a first attempt–to reconcile the two data sets.”

Following soon after the paper in Quaternary International, he was part of a remarkable group of proboscidean and genetic scientists whose paper The evolutionary and phylogeographic history of woolly mammoths: a comprehensive mitogenomic analysis analyzed 143 woolly mammoth mitochondrial genomes.

As Dr. Widga said with characteristic enthusiasm about his work in paleontology, “It’s always fun! There’s always a mountain to climb and a vista to see!”

*****

A Mammuthus columbi-sized THANK YOU to Dr. Chris Widga, who was remarkably generous with his time, with images to use and with answering my many, many questions (both for this blog and for my own proboscidean curiosity).  Speaking with him was delightful; he is an incredible ambassador for science in general!

Another sincere THANK YOU to Ron Richards for providing the great images of the Indiana State Museum collection. 

References:

1. Widga, C., Lengyel, S. N., Saunders, J., Hodgins, G., Walker, J. D. & Wanamaker, A. D.: Late Pleistocene proboscidean population dynamics in the North American Midcontinent. Boreas. 10.1111/bor.12235. ISSN 0300- 9483.
2. Widga, C., et al., Reconciling phylogenetic and morphological trends in North American Mammuthus, Quaternary International (2017), http://dx.doi.org/10.1016/j.quaint.2017.01.034
3. Chang, D. et al. The evolutionary and phylogeographic history of woolly mammoths: a comprehensive mitogenomic analysis. Sci. Rep. 7, 44585; doi: 10.1038/srep44585 (2017).

Mastodon fossil at the Illinois State Museum; image courtesy of Chris Widga.

Eliann Stoffel – Unlocking the Secrets of a Forgotten Mammoth

A rather large bone, revealed by his bulldozer, prompted William McEvoy and his crew to cease work on the road and call the police. The police then called the local archaeological society, who, in turn, called an archaeologist at the local Natural History Museum.

When word got out that a mammoth had been discovered, visitors began pouring in to see the site.  Just a few miles outside of the town of Kyle in Saskatchewan, Canada, the excavation of these fragile bones from the hard clay was witnessed by an ever-growing number of people.  It is estimated that 20,000 visitors came to see the site that autumn in 1964.

Embed from Getty Images

 

Eventually, the plaster casts protecting the bones were taken to the Natural History Museum (now known as the Royal Saskatchewan Museum); radiocarbon dating was conducted.  Possible museum displays and skeletal reconstructions were discussed.

And then?

Nothing.

Once the cause of great local excitement, the bones of the Kyle Mammoth faded from view.

The references above to archaeology are not errors.  Although the bones found were paleontological in nature, the focus on the find—and, indeed, the very reason they were recently resurrected—was to determine whether there was any evidence of human-proboscidean interaction.  When no stone tools were recovered in the surrounding sediment and with no obvious signs of butchering on the bones, interest in the fossil seems to have collectively disappeared.  For over 50 years, the various bones found on that stretch of road have been shelved in the Museum’s collections.

“I had always planned on doing my thesis at the University of Saskatchewan and I knew I wanted to do my thesis on hunting and butchering strategies utilized by Paleoindian people,” explained Eliann Stoffel, a recent graduate, in an email.

Her interest was not specific to any one species of megafauna. She hoped to study any and all large animals ancient people may have hunted: camels, bison, horse, proboscidea.

“I had approached my supervisor, Dr. Ernie Walker, with this topic and he had spoken with a member of the Saskatchewan Archaeological Society, Frank McDougal, who had suggested taking a look at the Kyle Mammoth.”

Which is how the long-forgotten fossil came back into view in 2015.

“We knew that the mammoth belonged to a time when people were in North America and actively hunting mammoths so we had the possibility of finding some sort of evidence of humans on the Kyle mammoth.”

This evidence is rare in the area known as the Northern Great Plains, an area that encompasses Saskatchewan (as well as another Canadian province and five U.S. states).

“It was one of those projects,” she said later by phone, “that, as soon as it came up, I couldn’t turn it down.  It needed to be done.”

Travelling between Saskatoon and Regina (where the Royal Saskatchewan Museum and the fossil are located), Eliann spent many hours studying and analyzing the bones from the 1964 excavation.  This included five boxes of bone fragments as well as 56 complete or near-complete bones, such as vertebrae, mandible, a partial tusk, and ribs.  Also included were ungulate bones, which—like the mammoth—did not comprise a full skeleton and did not present any clear association with its proboscidean fossil companion.

 

About 20% of the mammoth skeleton survived; image courtesy of Eliann Stoffel, University of Saskatchewan

 

Eliann’s thesis presents a comprehensive taphonomic analysis of the mammoth bones, and this was done because she and her advisors “knew that we needed to keep in mind that we might not find any evidence of human involvement.”

The idea of determining who or what made any kind of marks on a fossil seems like an overwhelming challenge.  This was not an animal that died the other day.  In this case, it died roughly 12,000 years ago. That is a considerable amount of time in which—after an animal is butchered, killed or otherwise dies of natural causes–it can be scavenged after death, it can be moved and scraped by natural elements, it can be affected by its fossilization, and then possibly affected by the process of discovery (in this case, by a bulldozer). How is anyone able to read the marks on fossil bones and know what they represent?

“[T]he first giveaway is the colour,” she wrote. “Bone, when it has been buried for a long time, tends to become stained from the surrounding sediment but only the outer surface. So when someone (an excavator) knicks the bone, the unstained inner portion of the bone is exposed and tends to be a lighter colour.

“The other indicator can be the clustering of marks. [With] butchering, there tends to be more than one cut mark on the bone in the same general area, usually at muscle attachment sites, and they tend to be orientated in the same direction. Rarely do you find cut marks that intersect each other. They are usually parallel. In accidental knick marks there is usually just the single mark and it tends to be located in a spot that you wouldn’t generally find cut marks (i.e. on joint surfaces or midshaft of a long bone).”

 

 

Photo of the Kyle Mammoth right mandible from her thesis; courtesy of Eliann Stoffel, University of Saskatchewan

 

Contrary to initial review in the 1960s, Eliann discovered a few tantalizing signs that this mammoth may have, indeed, suffered from trauma induced by ancient humans.  From a suspicious-looking lesion to a possible puncture wound on vertebrae to a puzzling set of lines in a bone fragment, there was reason to wonder whether humans had been responsible for these scars.

Ultimately, however, the first two were determined to be pathological. The lesions conform to known understanding of malnutrition in the form of osteolytic lesions.

Knowing her hope to find evidence of human interaction, I asked if this was a bit of a disappointment.

“[I]t was a bit of a kick in the knees,” she admitted, “but still a super interesting avenue of study in terms of pathology. I am more than thrilled with my findings though!”

 

Images courtesy of Eliann Stoffel, University of Saskatchewan

 

Another startling discovery appeared in what she describes as a “spongy” bone fragment, shown above, which contain traces of blood vessels.

“I remember bringing it to my supervisor and we both scratched our heads over it…So we called on our resident bioarchaeologist Dr. [Angela] Lieverse to take a look and she wasn’t sure but suggested possibly something vascular. Sure enough, when I searched for studies fitting that criteria, a couple articles turned up. So it seems that it is an occurring phenomena but possibly not that common,” Eliann wrote.

Ultimately, Eliann determined that this was a young male woolly mammoth (between 28 – 35 years old) that was still growing at the time of its death.  She estimates it was 328.66 cm (approximately 10.8 feet) tall.  While the large open wound on one of the vertebra points to a possible puncture wound from Clovis weaponry, other pathological features point to a mammoth suffering from malnutrition.

Eliann’s enthusiasm for those who helped her in her research was apparent.

“[T]he folks at the [Royal Saskatchewan M]useum were more than happy to help in any way possible,” she expressed, “and it is something that I have always appreciated! Also my major funders [were] the Saskatchewan Heritage Foundation, the Saskatchewan Archaeological Society, and, of course, the Department of Archaeology and Anthropology at the [University of Saskatchewan].”

More than just a strenuous academic endeavor, Eliann’s research has painted a picture that has been missing for decades on a significant local paleontological find.

“The [people in the] town of Kyle identify with this mammoth.  As you come into Kyle, there’s this statue of a mammoth.  Their sign that says ‘Welcome to Kyle’ has a picture of a mammoth on it.  It’s clear that they identify with it.”

 

 

A Mammuthus primigenius-sized THANK YOU to Eliann Stoffel—not only for her time in emails and by phone–but also for her gracious permission to use a number of pictures from her work!  Her thesis is fascinating and well written.  I recommend it to all!  Eliann, may you find many mammoths with evidence of human association in the future!

Another enormous thank you to Dr. Angela Lieverse, head of the Department of Archaeology and Anthropology at the University of Saskatchewan, who was also responsible for the generous use of images from Eliann’s thesis!

And I am very grateful to Dr. Emily Bamforth at the Royal Saskatchewan Museum for connecting me to Eliann! I could not have written this otherwise. THANK YOU!!

*****

References:

1. The Kyle Mammoth: An Archaeological, Palaeoecological and Taphonomic Analysis, Eliann W. Stoffel, July 2016, University of Saskatchewan
2. Shedding Some Light on the Kyle Mammoth, David Zammit, Swift Current Online, Nov. 13, 2016; the article that brought Eliann Stoffel and the Kyle Mammoth to my attention!
3. PDF about the Kyle Mammoth from the Royal Saskatchewan Museum

Screenshot from the aforementioned PDF of the Kyle Mammoth, Royal Saskatchewan Museum

Maiasaura Life History Project: Paleontology at an Entirely New Depth (Part 1)

I envy the future.

I really do.

Every time I read a dinosaur book—whether a kids’ book with my nieces and nephews or otherwise—I am reminded just how much we’ve learned since I was young. It is staggering, the amount of information available to dinosaur enthusiasts. Whether it is in the number of new species discovered each year, the unbelievable details paleontologists glean (from teeth alone!), or the new technology that helps scientists unravel the once unknowable.

If this is what we know now, and in the relatively brief time since paleontology was first established, what are we going to know fifty years from now? A century? A millennium?

I think about the future almost as much as I marvel at the past. Assuming our knowledge base only increases, the future of paleontology promises to reveal what can only be—at this point in time—imagined.

Which is why when I learned of the Maiasaura Life History Project, I had to know more.

Dr. Holly Woodward Ballard wants to flesh out one particular species of dinosaur such that we know it almost as intimately as living animals today.  That species is a type of hadrosaur, an extinct herbivore from the late Cretaceous. Thanks to almost 40 years of excavation in Montana, we have thousands of its fossils from which to extract information and this, according to Dr. Woodward Ballard, is to be her life’s work.

Dr. Holly Woodward Ballard at Branvold Quarry, August 2015; Photo taken by Dr. Karen Chin, courtesy of Dr. Woodward Ballard

Maiasaura peeblesorum was inadvertently discovered in the late 1970s, both by the people who initially found the bones and by the paleontologists who eventually described them.  “Inadvertently” because Marion and John Brandvold, the people who found the bones, didn’t know what they’d found, and because Dr. Jack Horner and Bob Makela—who had done extensive research prior to their expedition—did not expect to find the object of their search in a local fossil shop they visited on a whim.

The 1988 book “Digging Dinosaurs” by Jack Horner and James Gorman describes this discovery. In it, there is a fascinating anecdote: Prior to 1978—the year Maiasaura peeblesorum was found—they say that the number of adult fossils found globally could be listed in a volume the size of a book. The number of juvenile fossils could be listed in something the size of a pamphlet.  But the number of known baby fossils could fit on an index card.

All of that changed thanks to Dr. Horner and Bob Makela. The Brandvold bones gave them specific clues about where to look and what to look for.  Their subsequent excavations revealed not only numerous baby dinosaurs, but actual nests. These significant discoveries prompted the following revolutionary ideas: that some dinosaurs may have cared for their young and that they may have been warm-blooded. The latter hypothesis continues to be debated today.

Paleontologists have been digging in the area ever since.  Their efforts have produced one of the few species of dinosaur to be so well represented in the fossil record, a fact that inspired Dr. Woodward Ballard in her research at Montana State University.

Maiasaura field site in Montana, photo courtesy of Dr. Woodward Ballard

Jack Horner, her PhD advisor, proposed the idea that she focus on population histology—revealing the growth history of a specific dinosaur species.  Given her interest in osteohistology and the wealth of Maiasaura fossils, this seemed a perfect fit.  Her dissertation was but a prelude to the work that followed.

This past October, Dr. Woodward Ballard, now of Oklahoma State University, Dr. Liz Freedman Fowler and Dr. Jack Horner of Montana State University and Dr. Jim Farlow of Indiana Purdue University published a paper in Paleobiology on the growth and survivorship rates of Maiasaura peeblesorum.  The paper was unique in that, unlike most dinosaur species, they had 50 bones with which to analyze and sample.

Bone microstructure, much like trees or proboscidean tusks, records the growth of an animal in rings. In this case, Dr. Woodward Ballard was able to identify the “lines of arrested growth” (or “LAGs” for short).

“A LAG,”she explained by phone, “represents a period of missing time.”

Growth rings in Maiasaura bone, courtesy of Dr. Woodward Ballard

The paper is a fascinating glimpse into the depth of detective work paleontologists must do in order to understand long extinct species. Comparing bone growth in extant reptiles and mammals to these fossil bones, using complicated statistical models, and analyzing bone structure under the microscope, the authors offer an extraordinary view into the life of Maiasaura.  It is, to date, the largest sample set of a single dinosaur species analyzed to such a degree.

Fifty Maiasaura tibiae from three Montana bonebeds provided the details. This specific leg bone was chosen for analysis because it displays histology so clearly.  The same is not true, for example, of a hadrosaur femur.

“The femur,” Dr. Woodward Ballard said, “is special in all hadrosaurs, [not just] Maiasaura. It has this big flange coming off of it, and it’s this spur bone that a fairly large tail muscle was attached to.”

“Because bone responds to stress and remodels based on the stress that’s applied to it, this flange of bone is always changing and getting larger as the [animal grows.] The remodeling that occurs within [this] bone overprints–or erases–the original signal that was there. So it’s very hard to get at that same record of growth in the femur because it’s constantly being erased in that particular area.”

One of the things they discovered through lines of arrested growth (LAGs) was that most of the tibiae in this study belonged to Maiasaura younger than a year old.

But deciphering this required understanding bone growth in living species.

“We have to use modern animals and use what we see in their bones as a basis for what we say in the fossil record,” she replied when asked about this. “We have to assume that the same processes today were working back in the Cretaceous (in this case).”

So they looked to previously published alligator studies and those of the red deer on the Isle of Rum, Scotland—one of the most extensively studied mammals anywhere in the world.

Acknowledging that these inferences should be treated with some caution, they note similarities in tibia bone growth between alligators and Maiasaura. Growth marks within the bone and lines of arrested growth (LAGs) are similar in red deer and this species of dinosaur.

“When the growth is being kept track of from year-to-year, we find that one LAG appears every year for every year of growth,” she explained.

Hence, if there are no LAGs in the bone, it indicates that the animal was less than a year. And the high mortality rate among such young animals—considerably smaller than their enormous parents and therefore not as able, perhaps, to aptly defend themselves—is not necessarily surprising.  The paper also calculates survivorship rates among Maiasaura, enabling us to know how old the dinosaur was at sexual maturity, how long it tended to live, the age at which it was at higher risk for mortality among its species.

“Once I compiled the data from Maiasaura,” she said, “got all the bone measurements, got all the LAG circumference measurements within the bones—I realized that I wanted this paper to be more than just quantitative and simple growth curve graphs. I mean, I could do that much, but I really wanted it to be statistically strong, very robust, something that followed the rules put forth by other papers, such as the Steinsaltz and Orzack paper. [Dr. Liz Freedman Fowler] was just a natural choice to have to help me figure out what to do with all this data.”

————–

In Part 2: more detail about the Maiasaura peeblesorum survivorship curves, as well as applying complicated statistical methods to paleontological data.

An enormous and sincere thank you to Dr. Holly Woodward Ballard for her generosity: her time, her patience, her willingness to go over points I had difficulty understanding and for the beautiful pictures accompanying this post!

References:

1. Maiasaura, a model organism for extinct population biology: a large sample statistical assessment of growth dynamics and survivorship; Holly N. Woodward, Elizabeth A. Freedman Fowler, James O. Farlow, John R. Horner, Paleobiology, October 2015
2. Digging Dinosaurs, John R. Horner and James Gorman, 1988, Workman Publishing Ltd
3. Largest dinosaur population growth study ever shows how Maiasaura lived and died, Montana State University, MSU News Service

Treasured copy of “Digging Dinosaurs”, the book that details the discovery of Maiasaura peeblesorum and its nests, signed by Jack Horner at the Boston Museum of Science when the author of this blog met him in 2013

Strange Monsters and Turkey Tracks

Mary Anning was only 5 or 6 years old when she started down the path of discovery; Edward Hitchcock was in his late 30’s. Born on different continents 6 years and 3 days apart, both contributed to a world in which science was blossoming in new and exciting directions.

Their lives couldn’t have been more different.

Mary Anning was born May 21, 1799, to Molly and Richard Anning.  She and her older brother, Joseph, were the only children out of ten to survive to adulthood.  They learned from their father how to find fossils along the shore of their home in Lyme Regis, England. Mary accompanied her father on these hunts from age 5 or 6.  She learned how to excavate fossils from the rock, how to polish them, how to sell them to local tourists.

Lyme Regis, Dorset looking along the beach towards Charmouth, with the promenade to the left. The coast contains many fossils in the rocks which draws tourism from around the globe. Photo by Chris Hopkins, courtesy Getty Images. This is where Mary Anning searched for fossils throughout her life.

*****

When she was 11, Mary found her first major discovery: the complete skeleton of the first known ichthyosaur. Her brother had found its skull the year before—the same year that their father died—and she had gone back to excavate further.

Its discovery puzzled scientists at the time. Extinction and evolution were concepts that had yet to be introduced. The first dinosaur, Megolosaurus, would not be named until 13 years later; the actual term ‘dinosaur’ would not appear until 1842.  So this skeleton, with components recognized as those of lizards and fish, was utterly alien to the world.

 

Images of Stenopterygius quadricissus at the Yale Peabody Museum; this is a “thunnosaur ichthyosaur”, as described here at Wikipedia.  In any case, not the exact type of ichthyosaur–a marine reptile that co-existed with dinosaurs–discovered by Mary Anning, but it is something similar. Photos taken by the author.

*****

And it was just one of many new species Mary would go on to discover in her lifetime.

In 1823, she would find the skeleton of what was eventually known as Plesiosaurus giganteus. Five years later, she would find a pterosaur (Dimorphodon).  She discovered a transitional fossil—one that actually demonstrates in its skeleton traits that show it is evolving from one form to another—in 1829. That became known as Squaloraja polyspondyla. In 1830, she found another plesiosaur: Plesiosaurus macrocephalus.  Ultimately, she would also discover 34 new species of ancient fish.  She correctly identified fossilized dung within ichthyosaur skeletons, a type of fossil newly named coprolites and described by William Buckland after discussions with Mary Anning and Gideon Mantell.

 

Part of a life-size diorama at Dinosaur State Park, Rocky Hill, CT; replicas of Dimorphodon, a pterosaur discovered by Mary Anning in 1828, can be seen in the top right. Photo taken by the author.

Image of Squaloraja polyspondyla, a type of fossil discovered by Mary Anning in 1829. You can read about this in more detail at the blog Mary Anning’s Revenge here. 

Drawing of Plesiosaurus macrocephalus discovered by Mary Anning in 1830; image courtesy of Brian Switek and Wikipedia. 

Images of a polished section of Ichthyosaurus communis vertebrae in a drawer at the Beneski Museum at Amherst College.  Not only does this come from Lyme Regis, but this is the type of Ichthyosaur discovered in 1832. Mary Anning found the skull and was convinced that there was nothing more to be found. Fellow-fossil hunter Thomas Hawkins, however, believed there was more.  She led him to where she’d found the skull, and he and his team did find the rest of the skeleton.  When the skeleton shattered as they moved it, Mary Anning helped Hawkins put it together.

*****

Her discoveries fueled scientific revelations, were studied by the most prominent scientists of the age, and were discussed in the relatively new Geological Society of London.

As a woman, she was never allowed to attend any of their meetings or lectures.  Moreover, she was almost never credited for her remarkable fossil finds.

Her male friends could attend university (as both a woman and a member of the Dissenter religion, this was not an option), join scientific organizations, have papers published, discuss the latest scientific research among peers in professional institutions, travel extensively (without chaperones) and make substantial financial gains in their careers.

Mary’s life was marked by periods of financial gain and of teetering terribly close to financial ruin. She had three years of formal education.  She traveled to London once.

And yet, she constantly persevered. Her work enabled her to buy a home for her family at the age of 27, the first floor of which she created her fossil shop.  Although she was not privy to university resources, she taught herself scientific illustration.  Using marine life from the local beach, she taught herself anatomy through dissection.  She was in communication with and visited by scientists from all of Europe.

Embed from Getty Images

Illustration of Mary Anning selling fossils by Dorling Kindersley (DK), courtesy Getty Images.

In fact, some of the very same people in communication with Edward Hitchcock were communicating with or visiting Mary Anning: Charles Lyell, Roderick Murchison, Richard Owen, Gideon Mantell, and William Buckland.

Across the ocean, Edward Hitchcock was born in Deerfield, Massachusetts on May 24, 1793, several years before Mary Anning was born.  He would also outlive her.  While she died of breast cancer at the age of 47, Edward died at 70.

Had he been African-American (or simply African) in the newly-formed United States or a woman anywhere, his opportunities would have been severely limited, but he was none of those things.  Still, although he hoped to study astronomy at Harvard, he ultimately never attended college.

He did, however, become the first state geologist for Massachusetts in 1830 (the same year Mary made one of her major fossil discoveries).  He created the first geologic map of Massachusetts—only the 2^nd ever created in the country—in 1832.  He believed the state exhibited proof of the Great Flood referenced in the Bible; it was later found to be remnants of the Ice Age.

 

Sign at Dinosaur State Park that offers a brief history of ichnology in New England. Edward Hitchcock is pictured at the very top. Below that, a drawing of the fossil tracks found by Pliny Moody–a name you will see in marble in the “Donors to the Footmarks” frame further below. Photo taken by the author

*****

Remarkably, he believed that women should receive education and learn about science. One of his well-known students was Mary Lyon, a woman who went on to found Mount Holyoke Female Seminary (now known as Mount Holyoke College), among some of the country’s first academic institutions for women. Orra White Hitchcock, who married Edward in 1824, was a prolific artist and scientific illustrator.  She created many of the illustrations he used in his classes.

Drawing of plesiosaurus skeleton by Orra White Hitchcock, 1828 – 1840, Classroom chart on linen, courtesy of the Archives & Special Collections at Amherst College

 

In 1835, things changed abruptly.  Dr. James Deane, from a nearby town, wrote to Edward about tracks found in stone slabs that were to be used to build a sidewalk.  Edward dismissed their importance until the surgeon sent him plaster casts of the tracks.

Most people referred to these tracks, seen in other local stone slabs, as “turkey tracks”.  Edward believed they were created by birds.  It was a belief he would defend for the rest his life, despite new discoveries that may have indicated otherwise.

Wild turkey tracks in the snow, late Spring, New England; photo taken by the author

Wild turkey in the Fall, New England; photo taken by the author

In part, his theory made sense.  The tracks looked remarkably similar to the familiar tracks of extant turkeys, and fossils of any ancient creatures responsible for the tracks in stone were not found.  New England, with its acidic conditions and lack of fossil-preserving stone, is not fossil-friendly.

Edward created a new science he named “ornithichnology,” a name that references birds, but was later shortened to just “ichnology” by William Buckland.

Images of the first documented fossil footprints, discovered in 1802, displayed at the Beneski Museum at Amherst College, part of the Hitchcock collection. Photos taken by the author

Fossil tracks displayed at the Beneski Museum at Amherst College. According to Window into the Jurassic World by Nicholas G. McDonald, these tracks were the “gem” of Hitchcock’s collection (pg. 58, Figure 6-8). This slab was originally used as paving. Photo taken by the author (of this blog)

*****

While major discoveries of reptiles and dinosaurs were starting to pepper European science, Edward continued studying fossil tracks and traces.  He wrote about his work and his theory to the men on the forefront of these discoveries (as mentioned earlier, women were not allowed or, apparently, credited). He began publishing books and submitted papers to the Yale American Journal of Science.

Richard Owen disagreed with Edward’s findings at first.  He would eventually change his mind after describing an extinct bird in 1939 (the ‘moa’ of New Zealand).  In 1841, Charles Lyell actually visited Edward and became a prominent supporter.

Although Mary Anning discovered and identified coprolites more than 15 years earlier, Edward discovered these fossils in 1844 in Chicopee Falls, Massachusetts.

Coprolites displayed in a drawer at the Beneski Museum at Amherst College.  These are not necessarily those discovered by Edward Hitchcock in 1944. Photo by the author

 

His two major works outlining his life’s work were published in 1858 (“Ichnology of New England“) and then two years following his death in 1865 (“Supplement to Ichnology of New England“).

He maintained that these fossil tracks were made by birds, and his work was heavily influenced by his desire to find proof of God in nature. In his own words, he taught “natural theology.”

 

The book Ichnology of New England, written by Edward Hitchcock in 1858; copy displayed at Dinosaur State Park. Photo taken by the author

The Supplement to the Ichnology of New England, written by Edward Hitchcock but published posthumously in 1865; copy displayed at Dinosaur State Park. Photo taken by the author

Framed marble sign highlighting donors and the amount donated; displayed at the Beneski Museum at Amherst College; photo taken by the author

 

His efforts as college president in the 1840’s prevented the closure of Amherst College.  One of his particularly successful years was the same year that Mary Anning passed away, 1847.

Today, his vast collection–thousands of fossil footprints and traces–reside in the elegant Beneski Museum of Natural History.  We are extremely fortunate, as Edward Hitchcock made it very clear he did not want his collection owned by anyone who did not share his evangelical Christian views.  Although the college moved to a more secular philosophy, his family did not honor this request.

A small section of the Hitchcock collection of fossil tracks and traces at the Beneski Museum of Natural History at Amherst College.  This author encourages anyone interested to visit this amazing museum. Photo by the author

*****

Did Mary Anning and Edward Hitchcock know of each other across the Atlantic?  Did their names or their work ever come up in conversation? Did their mutual friends in science discuss them with the other?

There is no evidence to suggest this.

But the world would be increasingly changed thanks to their contributions, their dedication and their lifelong efforts.

“Mary Anning painting” Credited to ‘Mr. Grey’ in Crispin Tickell’s book ‘Mary Anning of Lyme Regis’ (1996) – Two versions side by side, Sedgwick Museum. According to the Sedgwick Museum, there are two versions. The earlier version is by an unknown artist, dated before 1842 and credited to the Geological Society. The later version is a copy by B.J. M. Donne in 1847 or 1850, and is credited to the Natural History Museum in London. Licensed under Public Domain via Commons.

———–

References:

1. The Fossil Hunter: Dinosaurs, Evolution, and the Woman Whose Discoveries Changed the World by Shelley Emling, 2009, Palgrave Macmillan
2. Window into the Jurassic World by Nicholas G. McDonald, 2010, Friends of Dinosaur State Park and Arboretum, Inc.
3. Curious Footprints: Professor Hitchcock’s Dinosaur Tracks & Other Natural History Treasures at Amherst College by Nancy Pick & Frank Ward, 2006, Amherst College Press
4. Amherst College Archives & Special Collections – Edward & Orra Hitchcock: https://www.amherst.edu/library/archives/holdings/hitchcock
5. Amherst College Digital Collections: https://acdc.amherst.edu

 

Locations:

1. Dinosaur State Park, Rocky Hill, CT
2. Beneski Museum of Natural History, Amherst College, Amherst, MA
3. Yale Peabody Museum, New Haven, CT

One of 61 drawings done by Orra White Hitchcock for use in Professor Edward Hitchcock’s classes on geology and natural history. This is a reproduction of a preexisting drawing. Pen and ink on linen, Mastodon maximus skeleton, 1828 – 1840, courtesy of the Archives & Special Collections at Amherst College

Bringing the Extinct Back to Life – Montshire Museum, VT

It’s just over the border of New Hampshire, this sweet jewel of a museum tucked amongst the woods in Norwich, Vermont.

I visited Montshire Museum for the first time last summer to see an exhibit featuring a replica of Sue the T. rex from the Field Museum.  Filled with interactive exhibits, it largely centers on children and families.  Its drawers of fossils and fossil casts, however, kept me eagerly occupied.  And–for the first time in my life–I was able to hold parts of a mammoth molar–one of the many fossils people could touch in a class taught by an engaging docent.

My reason for returning this summer was to see the Prehistoric Menagerie–an outdoor exhibit of sculptures.  Life-sized replicas of extinct creatures that lived during the Cenozoic era created by artist Bob Shannahan.

Thanks to a number of people, I knew there was a woolly mammoth among them.

In order to get to the museum itself, one first has to drive down a long, windy path through the forest.  I mention this because this is what I saw on my drive down:

Woolly mammoth sculpture by Bob Shannahan as seen through the trees on the way down into the parking lot of the Montshire Museum; image taken by the author

Knowing that it was a sculpture, rather than a living woolly mammoth, did not make it any less exciting for me.  I immediately got goosebumps.

Quickly, I parked the car, got my ticket, and went straight outside to explore.

Sculpture of woolly mammoth by Bob Shannahan at the Montshire Museum; image courtesy of the Montshire Museum

These are no ordinary sculptures.  That’s not actual hair on the mammoth: it’s a shaggy compilation of twigs and other natural plants and fibers.

According to the press release on this exhibit, the artist explained, “Once I choose the animal, I conduct my research, collect skeletal measurements, and make a small model out of wire and foil. Then I make a full-size drawing on cardboard and begin building the animal. The frame, made of steel rebar and aluminum screen, is used to depict the major muscle groups. It turns out that the autumn vegetation is perfect for the animals’ fur.”

Below, for example, is the entelodont–an artiodactyl that lived during the Eocene and Miocene.  You can read more about this animal in this great post by Dr. Darren Naish (TetZoo, Scientific American).

Entelodont sculpture at the Montshire Museum; image taken by the author.

Close-up of the entelodont head; notice the plants behind the ear; image taken by the author.

Close-up of the entelodont mouth; the teeth are made of individual stones; image taken by the author.

Whether one sees them up-close or from a distance, these are impressive replicas.  I marveled at their likenesses, awed that such detail and life could be constructed from plants.

“The vegetation he chooses for each sculpture has connections to that animal’s life,” explained Bob Raiselis, Exhibits Director at the museum, “[H]e’s using the materials of the natural world to create artistic works referencing creatures from that world that we can no longer see.”

American camel sculpture at the Montshire Museum; image taken by the author.

Sign at the museum with details about the sculpture and the plants used to create it; image taken by the author (it was a rainy day when I visited)

“They really do seem to come alive in David Goudy Science Park here at the Montshire,” Bob Raiselis wrote in an email, describing the outdoor area in which the sculptures were placed. “[W]e worked hard to place them in a way that might have made sense for each living creature. The animals in the exhibition wouldn’t all have been in one place at one time in history, but we think that there’s enough space in our outdoor landscape to include the creatures that Bob has created and their own time scales.”

By United States Geological Survey [Public domain], via Wikimedia Commons

“At the Montshire we like to point out the connections between what artists do and what scientists do – close observation, looking for connections, creative problem-solving, great use of imagination and visualization – and we’re pleased to have been able to show Bob Shannahan’s work here this summer,” wrote Bob Raiselis. “He’s an artist who has a deep interest in learning about the history of the creatures he models, and then he takes that history, the scientific facts available, and places his works in the context of where and how they lived. And he does it with such skill and sensitivity.”

Short-faced bear peering out above a hill at the Montshire Museum; image taken by the author.

Close-up of short-faced bear sculpture by Bob Shannahan at the Montshire Museum; courtesy of the Montshire Museum

Sculpture of Diatryma, an enormous bird that lived during the Eocene, at the Montshire Museum; the artist employed foam for the beak; image taken by the author.

“It was a long couple of days,” Bob Raiselis continued, “getting them moved onto the Museum grounds, placing them, moving them a bit, looking from different vantage points – but when we were done and that Wooly Mammoth was up on the hill in the middle of Science Park, it really was possible to imagine them living on the North American landscape.”

“It’s a very powerful thing, that kind of realization and engagement with what otherwise might be just a fact you heard somewhere about these creatures.”

————————————

Many thanks to Bob Raiselis and Beth Krusi of the Montshire Museum!

The exhibit is available through September 7th, 2015.

Image of woolly mammoth sculpture by Bob Shannahan at the Montshire Museum; image courtesy of the Montshire Museum

Meet Dr. Katy Smith – Mastodon Detective

If you imagine the Great Lakes region over 10,000 years ago, you might see large, hairy beasts with relatively straight tusks grazing around boggy areas or moving within dense forests.  Their fur and overall appearance might cause you to confuse them with woolly mammoths, but these are the mammoths’ shorter, stockier cousins.  And if any of them would let you get close enough to inspect their mouths, you’d see in an instant that their teeth are completely different than those of mammoths.

 

[image of contemporary boggy area in Alaska, courtesy Getty Images]

 

Whereas mammoths are believed to have eaten grasses and even flowers, mastodons needed teeth suited to the mastication of hardier stuff: shrubs, parts of trees, perhaps pinecones?   Mastodon teeth, with the bumps and ridges one might associate with carnivores, are easily recognizable as ‘teeth.’  Mammoths, in contrast, needed to grind food, producing teeth with spherical lengths of ridges across each tooth.

 

[image courtesy of Ron Richards, Indiana State Museum, for this post: Mammoths and Mastodons in Indiana – Part 1.  Can you tell which tooth belongs to which species?]

 

 

[image courtesy of Ron Richards, Indiana State Museum, for this post: Mammoths and Mastodons in Indiana – Part 1.]

And while woolly mammoths pervade popular culture and interest, there are some, like Dr. Katy Smith, Associate Professor of Geology at Georgia Southern University and Curator of the Georgia Southern Museum, who prefer their lesser-known cousins and have made fascinating contributions to our understanding of them.

Mastodon discoveries usually produce the fossils of a single animal, and rarely a complete skeleton. Rarer still, finding skeletal remains of multiple mastodons at the same site.

Such a unique discovery occurred in 2005, when more than 300 fossils were found in Hebron, Indiana.  Now known as the “Bothwell site,” it was originally going to be the location of the landowner’s pond.  Instead, Indiana State Museum paleobiologist Ron Richards and his crew uncovered bones that included numerous mastodons (Mammut americanum), giant beaver (Castoroides) and hoofed animals with even-toes (artiodactyls).

 

[images of the Bothwell site dig, courtesy of Ron Richards, Indiana State Museum, for this post: Mammoths and Mastodons in Indiana – Part 2.]

 

Four years later, the Bothwell site became the focus of Katy Smith, her dissertation, and two subsequent papers she co-wrote with Dr. Daniel Fisher at the University of Michigan.

But let’s take a moment to consider what paleontologists uncover. However rudimentary this may seem, it is important to note that bones are generally not discovered in neat order, intact and with each skeletal component attached where it would have been in the life of the animal.

Consider, too, that not all bones survive.  And those that do are often broken or in terrible condition.

So even at a site such as Bothwell, which produced lots of fossils, a paleontologist’s job is no less challenging.  The pieces of information are incomplete, mere clues to the animals that died there.

The questions, however, are profuse.

Why were so many animals found in that one spot?

If, as it is currently debated, mastodons shared behavioral traits with modern-day elephants, was this a family unit?

If so, was this group—like elephants–comprised largely of female and juvenile mastodons?

And why were other unrelated animals discovered among them?

Did a sudden disaster kill them all?  Were humans involved?

 

Embed from Getty Images

 

Sexual dimorphism is another way of referring to the traits that make an animal either female or male.  Some of us would assume, since mastodon pelvic bones were not among the Bothwell fossil assemblage, that the sex of these animals would remain unknown.

There were 13 mastodon tusks, only four of which were complete. And this, remarkably, is what prompted Katy Smith’s research.

“I wanted to know if I just had tusks, what can I do to figure out if I’m looking at a male or a female,” she explained by phone.

 

[image of Dr. Katy Smith measuring an African elephant tusk in (what this author believes must be one of the greatest places on earth) the basement and fossil collection of the University of Michigan; courtesy of Dr. Katy Smith]

 

“Other people have looked at [sexual dimorphism], but I wanted to look at it specifically with the Bothwell mastodons, because they were inferred to be female, and female mastodons are less common in the fossil record than males.

“When I presented preliminary results from my research in a paleontology class, the professor said, ‘Why don’t you try multivariate analysis?’ And it just kind of spiraled from there.”

‘Multivariate analysis,’ as the name implies, means using more than one type of measurement or observation towards a hypothesis.  In other words, rather than simply using size as a determination of sexual dimorphism, applying numerous methods and statistics that support or disprove it.

Already, the amount of information scientists have pulled from tusks alone is fascinating.

Tusks are teeth.  They are described, in Dr. Smith’s dissertation as “hypertrophic incisors.” And, unlike human teeth, they continue to grow the entire life of the animal. So where we can simply look at a human tooth and know immediately whether it is from an adult or a child, the same cannot be done with tusks.

What their hardy structure records includes the age of the animal, growth in winter or summer months each year, their overall diet, and periods of nutritional stress.  (As described in an earlier post, Proboscidean molars can even provide details regarding where they roamed during life.)

But much of this information can only be gleaned from well-preserved, intact tusks, as well as from cutting into and examining their chemical composition.

“If you don’t know what the sex of the animal is before you look at tusk microstructure,” she said, “it can be hard to interpret what you’re looking at.”

Part of what Dr. Smith hoped to discover were similarities in the tusks where sex and age had already been determined.  If certain structural elements were the same across female mastodon tusks, such that they tended to differ from male mastodon tusks, this might help determine sexual dimorphism in future tusk discoveries.

She also hoped to discover any similarities between the tusks of extant elephants and mastodons.

 

[image of longitudinally bisected tusk, courtesy of Dr. Katy Smith] 

 

Thus, she studied and measured tusks of both species from numerous museum collections. (Asian elephant tusks were not used, as female elephants of this species tend to have either tiny tusks or no tusks at all.)  She rather amusingly refers to the approximate amount of tusks involved as “5,000 pounds of tusk.”

Her dissertation and the two papers describe the type of analysis performed in detail.  Among them were canonical variates analysis (CVA) and discriminant function analysis (DFA).

“Fortunately, we didn’t have to cut into the tusks to do those measurements. You just insert a stiff wire into the pulp cavity.”

“We think about tusks sometimes as stacks of sugar cones, because they actually grow in a kind of [layered] cone structure. So you think about one sugar cone, and then you put another one inside that one and then another one inside that one and so on and so forth. And the last sugar cone is empty. There’s nothing in it. That represents the pulp cavity.”

“[Analyzing the] pulp cavity is probably one of the best single measurements that you can use to distinguish between male and females. [I]n females, that pulp cavity will terminate before the gum line, and in males, it will terminate after the gum line, closer to the tip.

“This is something that we saw in almost every mastodon. So it was kind of cool.”

 

 

[image of female mastodon skull and tusks, courtesy of Dr. Katy Smith]

 

“If we could have cut every tusk, I would have,” she admitted, and laughed. “But it was a matter of collecting these measurements at different museums. And so I would just go there and collect all of them, and that was how we’d get the pulp cavity depth.”

“I’ve always been interested in paleontology,” she said when I asked her how she got started.

“I’m one of those kids who just never grew out of it. My parents used to take me to the museum all the time, and I used to spend hours and hours staring at the dinosaur dioramas there, just loving it.  I told my kindergarten teacher I wanted to be a paleontologist. I never changed! My 5-year-old self grew up and became a paleontologist.”

But her interests moved away from dinosaurs when she realized that their fossil record in Wisconsin, her home state, was rare to nonexistent.

After all, she said, “I started just wanting to explore what was underneath my feet.”

It wasn’t until grad school at Michigan State, where she met the late Dr. Alan Holman, that she realized her passion for mastodons.  His own interest in the species was infectious, and it was through him that she learned of the numerous mastodon (Mammut americanum) fossil discoveries in the area.

“Wow!” she said, recalling her initial reaction. “There are over 300 mastodons in Michigan. This is exciting!”

[image of male mastodon skull and tusks, courtesy of Dr. Katy Smith]

Not surprisingly, she did her PhD work at the University of Michigan, home to Proboscidean expert Dr. Daniel Fisher, who was her advisor.

“I wanted to work with him,” she explained, “because I wanted to continue working on mastodons, and he had a couple of ideas for projects. One of them included this assemblage of mastodons from Indiana, which were—supposedly—all female.”

What she discovered regarding the Bothwell site is both thought-provoking and fascinating:

• 8 tusks were determined to be female; the other 5 are unknown
• the ages of the mastodons range between 19 and 31 years old
• there is evidence that at least one juvenile might have been among them (a “juvenile tooth crown” was found)
• given that two mastodons died in winter, and another two died either in late summer or early autumn, this indicates that the collective deaths of these animals didn’t happen at the same time (hence, not a single event)
• none of the mastodons appeared to be under nutritional stress when they died
• members of a family unit would be expected to have the same “isotope profiles”–chemical signatures in their teeth–but these do not

Based on the evidence provided, Dr. Smith wonders whether these animals were part of a meat cache for humans (members of the Clovis culture) that co-existed at that time.

But perhaps the single most remarkable result of her research is helping other paleontologists–who often have nothing more than a single tusk–determine the sex of that animal using her different types of analysis.

Prior to her dissertation, only one female mastodon tusk had been analyzed for growth rate.  To date, I am unaware of any other publication (paper or book) that helps detail the sexual dimorphism in mastodons by tusks alone.

When I remarked upon this, I asked her if others had cited her work.  Her response, after stating that others had, was equally fascinating to me.

“It’s always the hope as a scientist that you’re contributing in some way,” she said, “and you know that you’re contributing if somebody else is using what you’ve done.”

 

An enormous and sincere THANK YOU to Dr. Katy Smith for her generous and fascinating answers to my many questions, her gracious help when I had trouble understanding certain points, and for being so much fun with whom to connect! I cannot express how much I wish I could attend her classes, nor how fascinating I found her dissertation. I am profoundly grateful that she shared it with me!

A sincere thank you to my Dad, as well, for helping me understand tooth components (i.e.: dentin, cementum)!

**A quick reminder that I am neither a scientist nor a paleontologist, so any errors in this post are my own.

Bothwell Mastodont Dig, courtesy of Indiana State Museum; many thanks to Bruce Williams and Leslie Lorance!

—————

References:

• Life histories of female American mastodons (Mammut americanum): Evidence from tusk morphology, stable isotope records, and growth increments, Kathlyn Mai Smith, Dissertation, University of Michigan, 2010
• Sexual dimorphism of structures showing indeterminate growth: tusks of American mastodons (Mammut americanum), Kathlyn M. Smith and Daniel C. Fisher, Paleobiology, 2011
• Sexual Dimorphism and Inter-Generic Variation in Proboscidean Tusks: Multivariate Assessment of American Mastodons (Mammut americanum) and Extant African Elephants, Kathlyn M. Smith and Daniel C. Fisher, Journal of Mammalian Evolution, 2013

 

Other references:

• Woolly Mammoths’ Taste for Flowers May Have Been Their Undoing, NPR
• Fifty thousands years of Arctic vegetation and megafaunal diet, Nature, Eske Willerslev et al.
• Ancient Life of the Great Lakes Basin, J. Alan Holman, 1995, University of Michigan Press
• Mammoths & Mastodons of the Ice Age, Adrian Lister, 2014, Firefly Books Ltd.

 

[image of sign in the NY State Museum illustrating the size difference between an extant elephant, a woolly mammoth and the Cohoes mastodon; picture taken by the author]

From the Depths of an Indiana Cave: A Fossil Treasure Trove

Around perhaps 25,000 years ago in Southern Indiana, an injured Dire Wolf made its way into a cave and never came back out. With three good legs and one that had been out of socket for a year or so, the wolf crawled through the smaller spaces and eventually—whether through an accidental fall or otherwise—landed at the bottom of a deep pit. It was trapped.

Ron Richards, Senior Research Curator of Paleobiology at the Indiana State Museum, and his crew discovered its skeleton after digging in that particular room for 3 or 4 seasons.

Ron took that set of bones to pathologists for more information. However long that injury was sustained, and it was not a short amount of time, that wolf was a survivor. They determined the one leg probably didn’t touch the ground, but that it could probably still run using the other three.

“What normally is a circular ball-joint on his thighbone was flattened on one whole side,” Ron explained in a phone interview.

“I think that probably affected his ability to back out. Maybe he smelled some rotting carcass smell or something, got too near and couldn’t back out, and probably went over the top [of the pit.]”

A reconstruction of that event, complete with an actual cast of that specific room in the cave, can be seen at the Indiana State Museum today.

What may not be apparent was the work involved in creating that cast.

The word “cave” might invoke images of enormous open spaces underground. This is not at all that kind of cave. Not at the initial opening, nor at any space within as one moves deeper inside.

“Years ago, you had to go into a belly-crawl,” Ron said of the entrance, “but now we’ve moved through it so much, we can do a hands-and-knees crawl.”

They built a platform to work above water pooling at the bottom of the pit, and—in order to keep the walls dry for rubber molds—they used blowtorches. Ron, cave dig crewmembers and people from RCI (Research Casting International) worked together on the beginning stages of the room’s cast. The finished product was done at RCI headquarters in Ontario.

[Image of the cave cast and wolf replica, http://www.rescast.com, by Research Casting International for the Indiana State Museum]

Nothing done in that cave is an easy process.

When Ron first began digging in that cave, he said, “I thought it would take 9 people 9 days, and we could finish the project.”

That was in 1987. The dig was prompted by the discovery of a single peccary bone.

Ever since, for approximately two weeks each year, Ron and his crew have returned to dig.

“[It was] the first big cave dig we had done,” he continued, describing that first year. “We’d done a couple of mastodon digs at the time, but we really had no money for the budget. There was nothing there. We had no trained staff. We had almost no equipment.”

“I remember pulling this together, pulling different people from different sections of the museum.”

And when it came to potential funding for this excavation, Ron recalled that he was asked, ‘Can’t you do this another time?’

“I didn’t know what to say,” he admitted, “so I didn’t say anything. The next day, we got the gear loaded, and we headed down for the cave. We just did not look back!”

“As it worked out, we dug, we found more bone: parts of little peccaries, parts of big peccaries, and other animals that no longer occur in the region.”

Peccaries are relatives of modern pigs, but instead of upper canine teeth that curve up—as in modern hogs—their teeth “drive straight down like daggers,” as Ron explained. Today, modern peccaries live within the Southwest United States, as well as in Central and South America. But during the Ice Age, peccaries were common in Indiana and Eastern U.S.

[Pleistocene peccary by Karen Yoler, image courtesy of Ron Richards, the Indiana State Museum.  Per Ron Richards: “This image is artist Karen Yoler’s  concept of what the peccary looked like.  We did drop off the larger dew claws on the front legs and added a little more canine tooth size and gave it a more perpendicular orientation.”]

 

Embed from Getty Images

[Angry javelina–or collared peccary–close up. Javelina go by many names such as wild pig,boar,etc.; image and caption from Getty Images.]

Working deep in the cave initially, the crew created a system that they continue to use, with some improvements, to this day: some people dig in the cave and place the soil into buckets; other people haul the buckets out of the cave and bring them down to a stream; still others screen the soil for fossils.

All of the data is recorded; all of the soil is screened.

“Above you are big spiders—lots of cave spiders and cave crickets. They don’t bother you, but some people get the heebie-jeebies, you know? I mean, you look up, and there [are these] massive things moving around,” he said and chuckled.

In recent years, they’ve developed what Ron refers to as “tramways,” 60-70 feet of ramps created by parallel boards with cross slats. Tramways—some with rollers—help bring the buckets out of the entrance to the cave and down the hillside.

 

[Digging…with the tramway in position for hauling buckets of sediment out, image courtesy of Ron Richards, the Indiana State Museum.]

To help carry 15-20 buckets at a time down to the spring to be screened, they employ an ATV with a tractor.

“[From all of the] tons of soil that gets screened,” Ron stated, “[there remains some] soil that’s left with small bones. We bag that out, bring it back to the museum, and then they rescreen it and clean it. And then–spoonful by spoonful–they go under the binocular microscope, and they pick out all the small bones and teeth.”

His crew is a dedicated group: leaving their hotel rooms at 8am and working throughout the day—with a short break for lunch–until 5pm (or later if the weather holds). Ideally, there are nine crewmembers per season, but they have done it with less people. Digging has sometimes required breaking rock, so among the many tools used are sledgehammers and chisels.

 

[Digging for peccary bones, image courtesy of Ron Richards, the Indiana State Museum.]

 

Over the years, the cave rooms have gained descriptive names: the Peccary Room, for example, the X Room, and the Bat Room.

The “Microfauna Room” was named after the large amount of small bones they found when they began digging through the top layers of soil and rock. This is where the aforementioned Dire Wolf was discovered.

“Near the bottom of that room, down at the 25,000-yr level,” Ron explained, “we began to get fairly complete skeletons of things like Dire Wolf, Black Bear, an otter, a snowshoe hare, a lot of small shrews and mice.”

“We really believe that those animals fell in this pit. They dropped, and they went down about 15-20 feet. I think most of the time it was probably full of water.

“It’s just a lonely place to be. Whether they could stand at the bottom, I don’t know. But there’s no way out.

“There [was] enough mud washing in from the ceiling of that room that they were buried under real fine sediments. And that preserved them very well.”

Some of the fossils discovered have been both remarkable and rare. A tapir tooth—only the second to be found in the entire state of Indiana—was found in the cave. Several beautiful armadillo (Dasypus bellus) plates [osteoderms] have been discovered have been discovered (that is the actual name; ‘beautiful’ is not necessarily a description). Ron painted a picture of this by saying, “When one animal dies, there’s about 3,000 plates that disintegrate and go everywhere, like little dominoes.”

“Two years ago,” he said, describing the ‘Twilight Room’, “we started finding some articulated peccary skeletons.”

“Deep in the cave we didn’t find a lot of that. The bones would be disturbed, and you could just see sort of a jumbled mass that had been moved by water, by gravity, [or] by other animals.”

“In this room, we found things that were articulated, feet in place, all of the little toes in place. Really unusual.”

The earliest fossils found were parts of a giant land tortoise, a species that cannot live in cold climates. Finding this indicated that the area, at that time, did not freeze.

Also found were fossils of a pine marten, a species that, conversely, lives in Northern climates today.

And as for peccaries, Ron estimates that they have found the bones of approximately 650 individuals. They determined this number by by counting the total number of large, pointed canine teeth and dividing by four.

[Bones & skull of the flat-headed peccary, image courtesy of Ron Richards, the Indiana State Museum.]

“So the question is then: did they live here? Or did they all have a misfortune and die here? It’s a little of both, but it’s mainly that they probably inhabited this cave and rock shelter for most of that time period.”

Ron mentioned that a number of the fossil discoveries in the cave are new to him.

So how does one identify unfamiliar fossils?

“We have a general reference collection of modern bones,” he replied, “and there is a big collection at Indiana University, Bloomington that I had become very familiar with in the 1970’s and 1980’s.”

He went on to explain that he referenced available literature and visited other museum collections.

“I had written correspondence,” he continued, “and the mailing of specimens with several experts in the eastern United States. My foremost ‘mentors’ were Dr. Russell Graham (then The Illinois State Museum), and the late Dr. J. Alan Holman (The Museum, Michigan State University), but I also had open correspondence with the late John E. Guilday (Carnegie Museum of Natural History), the late Dr. Paul W. Parmalee (The McClung Museum, University of Tennessee), Dr. Holmes Semken (University of Iowa) and the late Wm. R. Adams (Zooarchaeology Laboratory, Indiana University).”

“Everything [is] dug in square units,” he said. “We have thousands of these units. We can show the distribution and abundance of anything that pretty much died in that cave for thousands of years.”

And the work is hardly done. Ron estimates that the digging portion may be completed within the next 5 seasons (5 years), but the analysis of the immense amount of fossils has yet to begin.

“We’ve got probably 30 radiocarbon dates from the cave. Every year, we get one or two more.”

Ron explained that the cave has, so far, produced “probably 7,000 small plastic boxes of small bones, and 2,000-3000 larger containers of larger bones.”

“It’s my job to identify those. But, you understand,” he said, laughing, “life is short. I could spend all my time, day and night, just working with that alone. It’s an immense project.”

————–

Many, many thanks to Ron Richards, whose generosity astounds me.  I am profoundly grateful for his time, his patience with my “volley of questions” and his fascinating descriptions.  It is always a pleasure and an honor connecting with him!

A sincere thank you to Bruce Williams for prompting this post!

**The name and location of this cave were intentionally left out for security reasons.

Embed from Getty Images

[Image of the Indiana State Museum, Getty Images]

Will the Illinois State Museum close?

 

Screenshot from an excellent and informative article by Bernard Schoenburg at The State Journal-Register

 

The doors to the Illinois State Museum are not shut today, and–fortunately–they are not set to close until at least August 8th, according to an article yesterday in The State Journal-Register.

When I asked Chris Young, spokesperson at the IL Department of Natural Resources,  if there were any updates, he wrote, “There is no specific date set to suspend operations. As we discussed earlier, there is more work remaining to properly store collections, return borrowed items and call back items loaned for research.”

To keep informed on this issue, please check out the following resources:

• Save the Illinois State Museum blog: https://savetheillinoisstatemuseum.wordpress.com (this page has contact details and how you can help: https://savetheillinoisstatemuseum.wordpress.com/2015/06/26/hello-world/)
• Save the Illinois State Museum Facebook page: https://www.facebook.com/pages/Save-the-Illinois-State-Museum/917517601639564?fref=nf
• Sign the petition on MoveOn.org: http://petitions.moveon.org/sign/governor-rauner-dont
• Save the Illinois State Museum page on the American Alliance of Museums: http://t.congressweb.com/w/?GILOPWGAPZ

The commission this week set a public hearing on the closure of the Springfield museum for 4 p.m. July 13 in Room 2012 of the Statehouse. Anyone wishing to give oral testimony or submit written testimony can contact the commission at 785-3208 or by email at facilityclosure@ilga.gov. The email address is the same for submitting public comments.–Bernard Schoenburg, The State Journal-Register

—————

References:

• Illinois State Museum To Remain Open Into August Pending Review by Bernard Schoenburg, The State Journal-Register, June 30, 2015, http://www.sj-r.com/article/20150630/NEWS/150639947

Thank you again to Chris Young at the IL DNR!  

Thank you to Samantha Reif, the American Alliance of Museums, those behind any of the “Save the Illinois State Museum” resources (Facebook page, blog), and to all who are working behind the scenes to prevent the closure of these museums!

 

Triceratops Fossil Will Remain in Boston!!

The triceratops fossil, named “Cliff”* after the grandfather of the man who originally bought it from the Christie’s auction in Paris and loaned it to the Museum of Science, Boston, WILL STAY IN BOSTON!!  The goal of $850,000 was actually exceeded (only 11 days before the deadline!) Additional money raised will go toward fossil maintenance, per the article in the Boston Globe.

THANK YOU TO EVERYONE who donated to this cause or made it known through word-of-mouth or online venues!!

CONGRATULATIONS, MUSEUM OF SCIENCE!

Screenshot of mos.org/keepcliff as it appears today

*Gender is not known in triceratops fossils, as I understand it, so this is not necessarily a male triceratops.

Thank you to Erin Shannon for keeping me in the loop!

Here is the Boston Globe’s article: https://www.bostonglobe.com/metro/2015/06/18/museum-science-gets-keep-cliff-triceratops/goTIqJg9hTslNm9xwWg48O/story.html