Ghostly Traces of Ancient Behemoths

A recent article in the New York Times described challenges facing the Iraq Museum. Heavily looted in 2003 during the US invasion, it reopened in 2015 with a considerable collection, yet still struggles with public engagement. Not surprising, as there appear to be few resources to help visitors, such as audiovisual aids or docents. But what struck me most were the words of Iraq’s Cultural Minister, Abdulameer al-Hamdani, who said, referencing the artifacts in display cases, “In a box, art has no soul.”  His statement revolved around context: if you don’t understand what you’re looking at, its impact may not be as powerful.  As NY Times journalist, Alissa Rubin, explained, “Great works like the three-foot-tall Warka vase…are arresting sights but much more so when their history is explained.”

This resonates strongly for me when thinking of paleontology.

It’s easy to be impressed with larger fossils, articulated skeletons displayed in life-like poses. Regardless of one’s level of interest or knowledge, we can appreciate a mounted Triceratops. We know what that is. When you learn about the research done within the bones, however, and discover how scientists are learning about growth rates, blood vessel volume, what that blood vessel volume means for the way that dinosaur looked, whether areas of the body were covered in keratin or scales, that mounted skeleton takes on an entirely new meaning.  It becomes fleshed out in our mental images.  It goes from, “yes, that is an impressive fossil” to “WOW.  What an incredible animal!”  And, consequently, we have more connection to it.

That connection, to me, is the “soul” referenced by Mr. al-Hamdani. The details an ordinary person wouldn’t see when looking at fossils are the very things that bring that extinct species back to life.

 

Image of ‘Cliff,’ the Triceratops fossil at the Boston Museum of Science, photo taken by Jeanne Timmons. (‘Cliff’ might imply we know the sex of this animal; we do not. I don’t believe this was named by museum staff.)

 

When a friend of mine mentioned an upcoming trip to White Sands National Monument, it was with a sense of excitement, and I was happy for him.  White Sands was a name I recognized. It was, after all, the site of an incredible discovery unveiled last year: Giant Ground Sloth fossil footprints interacting with fossil hominid footprints. Evidence that humans may have been stalking that sloth, perhaps hunting it or, as Ed Yong at The Atlantic suggested in his piece about the discovery, maybe toying with it. Whatever their intent, hominids were doing something that repeatedly caused the sloth to turn abruptly and leave prints suggesting defensive movement.  

Paleoart of the possible interaction between a Giant Ground Sloth and ancient hominids, as depicted by Alex McClelland from Bournemouth University

 

That research put the National Monument on the map for many of us. I’d read the research and the articles about it.  I had a general idea of what was there.  “Footprints preserve terminal Pleistocene hunt? Human-sloth interactions in North America” (the 2018 paper of that discovery) mentioned that sloth and hominid footprints are only two of several species that left tracks so long ago in what is now New Mexico.  Preserved tracks remain of camelids, canids, bovids, felids, and proboscideans (most likely Columbian mammoths, although mastodons are possible, too).

So I understood my friend’s excitement, and I shared it to the degree of what little I knew of White Sands at the time, but I think it’s fair to say our levels of excitement were distinctly different.

 

Image of fossil hominid footprint inside a fossil Giant Ground Sloth footprint, photo courtesy of David Bustos, White Sands National Monument, New Mexico

 

 

Then I connected with scientists actively researching there.  Dr. Sally Reynolds, Dr. Matthew Bennett and David Bustos are three of the co-authors on the aforementioned paper, and they are among the authors of yet another paper on White Sands to be published in this August’s edition of Palaeogeography, Palaeoclimatology, Palaeoecology.

“Soft-sediment deformation below mammoth tracks at White Sands National Monument (New Mexico) with implications for biomechanical inferences from tracks” offers detailed insight into mammoth footprints and how they impacted the ground upon which they walked. To do so, the scientists analyzed the rock below the tracks themselves.

This study is arguably an asset to ichnologists, those who specialize in fossil traces such as bite marks, scratches, footprints and more. It provides richly detailed graphics and descriptions of how the mammoths’ foot pressures affected the sediment. Because hominid tracks intersect and even step into mammoth tracks, these footprints are analyzed as well.

Admittedly, this information might not be first choice among those who aren’t ichnologists, but I guarantee you their interpretation of this information might be.

Understanding what these footprints reveal is like opening a window into a moment of that animal’s life.  It can tell us about the possible weight and size of the animal who made them; the stride of that animal; whether it was walking, limping or running; whether it was alone or not; and it tell us about the environment in which it walked.  These are clues into the behavior of the animal, an entire realm beyond its physical make-up.

 

 

Screenshot of mammoth footprint analysis (deformation structures) at White Sands by Bennett et al, “Soft-sediment deformation below mammoth tracks at White Sands National Monument (New Mexico) with implications for biomechanical inferences from tracks” 

 

 

This is exactly what interests Dr. Sally Reynolds, Senior Lecturer in Hominin Palaeoecology and Deputy Head of the Institute for Studies of Landscape and Human Evolution (ISLHE) at Bournemouth University.

“I’m interested in the footprint in the behavioural context,” she wrote in an email. “What do the footprints tell us about the snapshot of activity taking place?”

“I like to think in terms of how these people used their landscape,” she continued, referencing her work understanding the paleoecology of an area and how that impacted ancient hominids. “I ask myself and the team questions like:

1. Where was the water? Were they waiting by the water to ambush the prey animals?
2. What were they eating? Plants, insects, animal prey?
3. What sort of technologies did they have for collecting these? Evidence of hunting, but also gathering, trapping etc.
4. What sort of toolkits did they have to use? Stone tools, fire etc.
5. What were they afraid of? Predators, poisonous snakes, etc. These animals are still largely resident in the region today. There is much recent ethnographic and ecosystem evidence that can be considered when reconstructing the ancient worlds of these people.
6. Group size? Gender roles, presence of children, roles of children.”

While he focuses more on ichnology, that sentiment is echoed by Dr. Matthew Bennett, Professor of Environmental and Geographical Sciences, also at Bournemouth University.

“I am now more interested in behavioural ecology derived from footprints – basically how one animal (human or not) interacts with another,” he wrote. “This for me is where the excitement and new research frontier is.”

 

Fossil hominid footprint within a fossil mammoth footprint at White Sands, photo courtesy of David Bustos

 

Both scientists have published on fossil hominids–footprints and bones–and associated ichnofossils of other species for years. Their collective expertise lends crucial understanding to an area in which there are not just a few footprints here and there, but thousands upon thousands.

More importantly, these footprints—in some cases—go on extensively.

“Some of [the trackways] go for half a mile or a mile. We have a camel track that [is] almost two miles,” David Bustos, Resource Manager for White Sands explained by phone.  “Because these prints are so long, they allow you to see interactions that you wouldn’t see at other places. They’re so unique. There are prints all over the world, but to have prints that extend for such a long distance and keep interacting with other animals or people is very unique.”

I want to reiterate that point, because this is where my enthusiasm for White Sands became almost palpable: the tracks at that site are not only profuse, they can be followed over 1-2 miles.  If relatively short trackways have provided great insight into extinct behavior, these tracks offer potentially unparalleled revelations.

“[T]he thing about it is,” he continued, referencing the sloth and hominid trackways described in the 2018 paper, “it’s not the only occurrence.  This is happening over and over across Monument lands.”

 

Screenshot of fig. S3. from Supplementary Materials for “Footprints preserve terminal Pleistocene hunt? Human-sloth interactions in North America”

fig. S3. Map of part of the study site. The map shows sloth and human tracks as well as track density across the whole site (inset). Note the non-linear sloth trackways and sudden changes of direction. “Flailing circles” occur only in association with human tracks.

 

“We see human, mammoth, Giant Ground Sloth, and camel prints commonly together across the monument. Occasionally you’ll see bison and occasionally you’ll see dire wolf or American lion or some type of felid.”

“The proboscidean prints we have are amazing. We have thousands of these prints at the monument. (They are probably the most numerous track type we have.) In the tracks, you can see young and old animals.  Some places you can see the prints of the young running in circles and then nudging up against the larger animals perhaps to say ‘hello’ or [to] nurse.“

A fossil Giant Ground Sloth trackway at White Sands, photo courtesy of David Bustos.

 

But there’s a twist: seeing some of the tracks depends upon just the right environmental conditions.

As David explains, “You’ll walk by the same area for years, [and] then the conditions will change. There is now a fine salt crust on the surface, and in the crust you’ll find a whole new set of prints, only to be gone the next day. These are the trackways that we call ghost prints.”

“[We saw] thousands of new prints we’ve never seen before,” he said, illustrating just one example. “And they were gone two or three days later. You couldn’t see them anymore. [S]omething changed with the soil that didn’t leave a fine salt crust over everything.”

Alarmed, I asked him if this meant they were gone for good.  He assured me that, “They’re still there, so if we were to look for them with GPR [ground-penetrating radar] or scrape back the soil, they would be there. But they’re not visible to the naked eye. You can’t see them.”

Ghost tracks (or “ghost prints”) aside, there is another, more ominous threat to the trackways: erosion.  This has lead David Bustos and his team at White Sands to work diligently to preserve as much as they as quickly as they can.  They are a small operation.  They’ve looked to outside groups and experts to help understand the fossils, see the value of the site, get the word out and help save the footprints.  To that end, they have actually excavated tracks.

“[The footprints] that we have brushed open [are] a small sample of [specific trackways],” David expressed. “There might be 2-3,000 prints, and, of those, we might open up 15 prints or so.  [The reason we excavate them at all is to get a better] understanding of the different types of prints, how they differ from each other (are toes visible,  how deep are the prints, how did they walk, were they slipping in the mud), and to get [good] measurements for the gait and stride and pace and all of those types of things. After the measurements are taken and prints documented, the prints are filled in.”

 

Images of the various types of proboscidean footprints found at White Sands: what they look like above ground and then images of what they look like underground; photos and graphics from the National Park Service.

 

 

Despite their hard work, it is not always enough.

“We were seeing places where we know we’ve lost large-scale sets of prints and tracks from soil erosion,” he stated.

David compared the loss of those prints to a significant loss of books from the Library of Congress.  Losing those fossils is like losing an enormous “volume of data.”

“[T]hey’re incredible in the stories that they tell you,” he said.  “A mother carrying a child. Or an old person limping along w/a larger group. Or maybe a younger person sprinting along the larger group (deep prints that are nearly three times the length of a walking stride). You see people interacting with each other.  And you see people interacting with the megafauna.”

Still, he is hopeful.

“It’s been an amazing project and we’ve had a lot of great support from everyone who helped us to get where we are.”

“It seems like every year there’s more and more  discoveries.  We’ve looked at maybe less than 1% of 51,000 acres that could contain trackways.”

The published research done by David, Sally, Matthew and their co-authors is far from finished.  Offering me tantalizing clues, I would encourage everyone to keep an eye out for what comes next.

As far as the secrets revealed by White Sands National Monument, this is only the beginning.

Partial screenshot of an image from “Soft-sediment deformation below mammoth tracks at White Sands National Monument (New Mexico) with implications for biomechanical inferences from tracks” that illustrates where in White Sands the research was done and the megafauna that left footprints

 

*****

There is currently a Senate bill to make White Sands National Monument a National Park!!

More info here: https://www.govtrack.us/congress/bills/116/s1582/text/

Dr. Matthew Bennett has freeware that, as he describes it, “allows you to capture tracks digitally using photogrammetry (20-40 oblique photos with a digital camera), but crucially it provides you with a series of tools to analysis and compare those tracks. Unlike many 3D programmes that have to cater for lots of users with different requirements, this is purely for footprints.”

Find out more here: DigTrace, http://www.digtrace.co.uk

 

References:

1. Bennett, Matthew R., Bustos, David, Belvedere, Matteo, Martinez, Patrick, Reynolds, Sally C., Urban, Tommy; Soft-sediment deformation below mammoth tracks at White Sands National Monument (New Mexico) with implications for biomechanical inferences from tracks; Palaeogeography, Palaeoclimatology, Palaeoecology, 1 August 2019
2. Bustos, David,  Jakeway, Jackson, Urban, Tommy M., Holliday, Vance T., Fenerty, Brendan, Raichlen, David A., Budka, Marcin, Reynolds, Sally C., Allen, Bruce D., Love, David W., Santucci,  Vincent L., Odess, Daniel, Willey, Patric, McDonald,  H. Gregory,  Bennett, Matthew R.; Footprints preserve terminal Pleistocene hunt? Human-sloth interactions in North America; Science Advances, 25 April 2018
3. Bustos, David, Much More than a Sand Box: Fossil Tracks from the Lakes of the World’s Largest Gypsum Dune Field, Park Paleontology News – Vol. 09, No. 2, Fall 2017
4. Bustos, David, National Park Service, Lake Lucero Ranger Minute, YouTube, Nov 21, 2016
5. Bustos, David, Love, David W., Allen, Bruce D., Santucci, Vincent L., Knapp, Jonathan P.; Diverse Array of Soft-Sediment Fossil Vertebrate Tracks from the World’s Largest Gypsum Dune Field, GSA Annual Meeting, Denver, 2016
6. Martin, Anthony J., Dinosaurs Without Bones, Pegasus Books, 2014
7. National Park Service, White Sands National Monument, The Pleistocene Trackways of White Sands National Monument, 2013
8. Rubin, Alissa J., In Iraq Museum, There Are Things ‘That Are Nowhere Else in the World‘, NY Times, June 9, 2019
9. Yong, Ed, Fossilized Human Footprint Found Nestled in a Giant Sloth Footprint, The Atlantic, April 25, 2018
10. White Sands National Monument, New Mexico, USA

 

What a great honor and a pleasure to connect with Sally Reynolds, Matthew Bennett and David Bustos!! Sincere thanks to all of you!!  Sally, your kind responses to my emails, your fascinating answers to my questions, and your constant support on Twitter have been great.  Matthew, thank you for your detailed responses at a time when you were incredibly busy.  David, thank you for responding to my emails and for making time to discuss my questions further by phone.  I wish all of you the best with your research, and I cannot wait to read what comes out next!!

This post would not have been possible without the thoughtfulness and help of my friend, Dick Mol.  Dick: You are a wonderful and generous person. THANK YOU. This post is dedicated to you and Friedje.

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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!

 

Rewriting the Story of How They Died – Columbian Mammoths in Waco

[[The following text has been edited from the original post.  Email me for the original post: mostlymammoths (at) gmail.com or read the full scientific paper by the authors here.]]

*****

Sometimes, it just takes a different point of view.

The largest known potential nursery herd of Columbian mammoth fossils in the world exists in Waco, Texas.  Of the 25 mammoth skeletons found to-date, 16-22 of them died at the same time. Something catastrophic occurred to these animals in the Pleistocene, but just what remains inconclusive.

While some speculate death by lightning, disease or miring, the predominant theory maintains that this is a herd of mammoths that died and were buried in the same flash flood.  It’s an idea that has stuck for many years given the existence of aquatic fauna and the evidence of an ancient river upon which many of the fossils have been found.

Image of Female Mammoth “W” at the Waco Mammoth National Monument, photo by Larry D. Moore CC BY-SA 3.0, 2013

 

But Logan Wiest, Don Esker and Steven Driese of Baylor University have a different hypothesis, one published this past December in Palaios.  By studying traces on the bones available in situ, as well as those available in the nearby Mayborn Museum, they offer an entirely new idea: water didn’t kill them; its absence did.  Struggling to find water in a drought, these animals may have collapsed and died at a watering hole that could no longer sustain them or anything else.

Columbian mammoths were enormous animals.  In general, they are known to be much larger than woolly mammoths and considerably larger than mastodons, both of which were behemoths in their own right.

The mammoth skeletons at Waco are thought to be a matriarchal herd, consisting mainly of females and youth (no calves).  The evidence suggests a herd, and there is more research to be done to prove it using stable isotopes.  A single bull has been discovered in a different geologic layer.  Separate fossils of other species—none of them complete except for a western camel—have also been found throughout the site.

Don admitted he didn’t have an alternative explanation for the death of so many animals. He invited his colleague, Logan Wiest, to take a closer look at the fossil evidence.

“I’d brought [Logan] in hoping he’d look at the [site’s paleosols],” Don said. “I knew he was a trace fossil expert, so I’d hoped he [might] tell me a little bit about the conditions based on worm burrows, [for example].

“What he found instead was much more interesting! He found that there were all kinds of bite marks on the bones.  We didn’t find those all at once.  It actually took quite a while [before] we recognized what we were seeing as bite marks.  A lot of literature research and a lot of staring at bones.  Those bite marks shouldn’t have been there if the mammoths were immediately buried.

“One of the first things he noticed and was able to identify quickly were dermestid beetle bite marks: pits that the beetles dig in the bones when they’re going to lay eggs.

“I thought that perhaps [evidence of dermestid beetles] might be there, but I didn’t realize the significance of [that evidence].  He’s more of an expert on this than I am.

“And he knew that dermestid beetles don’t eat wet meat.  It actually has to be almost completely dessicated–no moisture left at all, just the fats and proteins–before the dermestid beetles will touch it. And that didn’t fit well with animals that were killed in a flood and rapidly buried.

“Dermestid beetles also don’t burrow. Even a single inch of soil is enough to keep dermestid beetles from digging down to perfectly good meat.  They can’t dig.”

FIG. 7.—Cubiculum isp. on various skeletal elements. A) Slightly elliptical, hemispherical bore on in situ rib of mammoth W. B) Hemispherical boring on mammoth U phalanx (545-BU-MMC). C) Shallow bore on femoral articulation surface 761a-BU-MMC. D) Shallow bore on eroded long bone of mammoth D limb fragment (203-BU-MMC). E) Hemispherical bore in cancellous bone on the surface of a spiral fracture (20-BU-MMC). F) Comparative trace generated by captive hide beetles on a wild-hog skull (Sus scrofa). Note the similarities in size and morphology to Figs. 7A-E.

 

Used with permission, PALAIOS, v. 31, 2016, doi:10.2110/palo.2016.053, © SEPM Society for Sedimentary Geology 2016.

 

“So, it was Logan looking at this and trying to think about what might be causing this instead of a flood, and he said, ‘Well, how about a drought?’

“I knew about some other evidence that really fit with that. So that clicked with me very quickly, particularly the fact that we’ve got both aquatic and terrestrial animals—a great diversity of them all in the same place.  What that suggested to me was a diminishing watering hole. And I wouldn’t have realized that if Logan hadn’t noticed the dermestids and figured out the drought angle.”

Beyond studying the available literature for trace fossil search images, they tested their ideas on the heads of deceased wild hogs using extant dermestid beetles. In effect: they put the fleshy heads into a contained area and let loose the beetles, who proceeded to consume all of the flesh, leaving clean skulls. It’s an efficient and chemical-free method used by scientists and museums the world over.  But for Logan, Dan and Steven, this provided more data for comparison. Traces left by the beetles on the wild hog skulls are similar to traces on the fossils in Waco.

 

Screenshot of a tweet regarding the use of dermestid beetles from Dr. Lisa Buckley, paleontologist and ichnologist at the Peace Region Palaeontology Research Centre

 

“Previous studies have attributed trace fossils of this size and morphology to dermestid beetles,” Logan wrote in response to what prompted them–of all insects that might have left traces on fossils–to think of dermestid beetles.  “We simply wanted to test this notion by providing bone to dermestid beetles and seeing if these traces could be duplicated under controlled conditions. The beetles came from a nearby museum, but they are also native to Texas. We used the head from a hog simply because wild hogs are easily accessible in central Texas.”

A true ichnologist, Logan added, “I’ve also spent a great deal of time observing bones of modern cattle that were scavenged upon in pastures near my home.”

They didn’t just find evidence of ancient dermestid beetle traces; they found traces of animals who gnawed at the bones: rodents and carnivores, including a possible saber-toothed cat.  It is important to consider that animals drowned and then rapidly buried in a flash flood would not be accessible to these terrestrial scavengers.  This indicates that these Columbian mammoth carcasses were exposed on land long enough to be at least partially devoured.

That, too, is key. Remember that most of these mammoth fossils are articulated skeletons, complete except for missing tails and parts of their feet.  In an area devastated by drought, even scavengers would lack the energy to completely devour and tear apart a carcass.  All of these clues add more weight to the scenario proposed by these authors.

FIG. 5.—Brutalichnus brutalis on M. columbi skeletal elements. A) Arcuate grooves on femoral head 761a-BU-MMC. B) Relatively deep, arcuate grooves on mammoth Q in situ patella. C) Isolated arcuate groove on proximal radius (40-BU-MMC) of mammoth B. Note the similarity in curvature between the arcuate groove and the saber-toothed cat canine recovered from WMNM. The tooth is 6.4 cm for scale. Also note the faintly colored lines that are parallel to the arc of the groove. Dashed white box highlights the area depicted in D. D) Close-up image of groove depicting the microfractures within the trace on 40-BU-MMC. Notice how the fractures are all open towards the upper-right corner of the image, indicating the trace was generated from a force moving from the upper right towards the lower left. E) In situ femur of bull mammoth at WMNM. F) Arcuate grooves on mammoth Q phalanx 522-BU-MMC.

 

Used with permission, PALAIOS, v. 31, 2016, doi:10.2110/palo.2016.053, © SEPM Society for Sedimentary Geology 2016.

 

Describing the tools they used to study the fossils in situ, Logan wrote, “The low-angle light creates a shadow which makes the small structures on the bone surface to be easier to see and photograph. We used a Dino-Lite portable microscope to study the fossils mainly because we are unable to transport the mammoth remains from the site to the laboratory. Studying the fossils in place is the best way to ensure preservation of the original positions.”

In other words, because the fossils remain where they were found, they studied those available directly at the site.  Their paper states that the in situ fossils comprise 30% of the available Waco fossils.  The rest reside at the Mayborn Museum, some of which are available in their collections, but most of which remain unopened in their plaster jackets.

“It’s an amazing site,” Don enthused, “and there’s decades and decades of research there, on top of potentially a lot more excavation, too, because they are in NO WAY finished excavating. What they’ve got probably represents a fairly small fraction of the whole deposit.

“One of the things that Logan and I were speculating about [is] if you’ve got a really big regional drought, that should show up in multiple places in the geologic record, especially right in that area.  The bed that we’ve got marking the drought as this depositional hiatus could be covered with bones for acres and acres in every direction.

“And we know that it’s covered in bones at least 80 or 90 feet away from where the known deposits are because we’ve done core sampling that have pulled out large bone fragments.  We only did a couple of them—a couple at random!—and they hit bones both times.”

 

FIG. 4.—Machichnus regularis on various skeletal remains of M. columbi (unless otherwise noted). A) Rodent gnaw marks on rib 764b-BU-MMC. B) Rodent traces on mammoth E limb fragment 203a-BU-MMC. C) Rasps on vertebra of in situ camel. D) Rodent gnaw marks on in situ neural spine of juvenile mammoth T in L1. E) Rodent traces on in situ left scapula of bull mammoth (Q) in L2. F) Close-up image of the same trace depicted in view E.

 

Used with permission, PALAIOS, v. 31, 2016, doi:10.2110/palo.2016.053, © SEPM Society for Sedimentary Geology 2016.

 

 

The Waco Mammoth site itself has been around for 39 years, but it has only been part of the National Park Service since July 2015, thanks to President Barack Obama and the work of many people years beforehand who helped bring that to fruition.  Don and I discussed this by phone, given the current political climate and the fears that some National Monuments might lose their status.

“That’s really worrisome,” he remarked. “And what really sticks in my craw about the Waco Monument in particular is that it’s costing the Federal Government almost nothing.  The city of Waco is paying for almost all of the upkeep.  The original buildings? That wasn’t tax money. That was done by good old fashioned fund-raising. And the day-to-day operations are almost all city.  There are a couple of rangers there alongside city employees and some signage and brochures. And that’s really all the Federal Government’s paying into it.”

“It’s a really incredible place.  There are not a lot of sites like this anywhere, as far as in situ fossils sites go.”

*****

A Mammuthus columbi-sized THANK YOU to Don Esker and Logan Wiest for their remarkable generosity in answering my questions and for sharing their research with me.  It was an enormous pleasure speaking with and communicating through email with them.  I loved reading their research and hearing more of the history behind it!!

You can read the paper here.

A sincere and enthusiastic thank you to Kathleen Huber, Managing Editor at Palaios, for her gracious permission to use the figures contained in this post!

References:

1. The Waco National Monument may represent a diminished watering-hole scenario based on preliminary evidence of post-mortem scavenging, Wiest, Logan A.; Esker, Don; Driese, Steven G., Palaios, December 2016, DOI: 10.2110/palo.2016.053
2. Waco National Monument, Waco, TX
3. City of Waco, TX – Waco Mammoth National Monument, Waco, TX
4. Mammoth Opportunity, Jeff Hampton, Baylor Arts & Sciences Magazine, Fall 2016
5. What is Ichnology? from Introduction to Ichnology, Anthony J. Martin, Emory University (This page offers a great explanation of some of the more technical ichnological terms included in the scientific paper referenced for this post. I also recommend Dr. Martin’s book, “Dinosaurs Without Bones” for a more comprehensive look into ichnology.)
6. Flesh-Eating Beetles Explained, Mollie Bloudoff-Indelicato, National Geographic, January 17, 2013

 

Screenshot of the entrance to Waco Mammoth National Monument from a video done by the City of Waco

A Personal Fossil Journey in New England

“Can you please help me find the Beneski Museum?”

This was the second student I’d asked. Initially, I’d asked a student for help finding the museum—no thank you, GPS–and then help with elusive parking. My request to the young woman in front of me was to help re-find the building I’d lost sight of amongst many other brick buildings.

She pointed me in the right direction, gave me detailed instructions, and added, “It will take you approximately three minutes to get there.” A thoughtful detail that made me smile that much more broadly.

Students with backpacks dotted the campus and passed me as I headed forward: some lost in thought, some in conversation, others laughing. Their presence, just as much as the rolling hills of manicured lawns, towering trees and historic buildings, made me feel right at home. Although not where I’d attended school, it felt similar, and I basked in the feelings that surfaced. Of course, none of these feelings included the stress or the struggles I felt throughout college. Long gone are the days of working most of the night on papers, studying for exams or the abject terror of oral presentations. No. These days I learn on my own, at my own pace, as I wish, and where I wish. I adore it.

But learning in this fashion is not at all linear.

A recent trip back to see Dinosaur State Park in Rocky Hill, CT, enabled me to re-read exhibits that didn’t mean as much to me when I’d first seen them so many years prior.

Images of Dinosaur State Park, Rocky Hill, CT, taken by the author

 

Since that time, I’d read Dr. Anthony Martin’s “Dinosaurs Without Bones”—a fascinating journey into the science of learning more about extinct creatures through fossil traces. I’d also spoken with paleontologist, Dr. Karen Chin, about both ichnology (the aforementioned science) and the work of Dr. Martin Lockley—a man who has spent a lifetime learning about and collecting fossil footprints.

Book cover to”Dinosaurs Without Bones” by Anthony J. Martin, Pegasus Books

 

So when I saw a small note about Edward Hitchcock and his collection of footprints, I decided to check it out.

Informational panel at Dinosaur State Park that mentions Edward Hitchcock and Amherst College, taken by the author

 

Which is a long way of explaining why I had traveled a couple of hours south to Amherst College.

I knew the museum offered other fossils along with Hitchcock’s fossil footprint collection, but I did not expect them to be as diverse or as impressive.

 

 

Columbian mammoth (Mammuthus columbi) skeleton at the Beneski Museum, Amherst College, taken by the author.  Smilodon and dire wolf skeletons are on the right.

Irish elk (Megaloceros hibernicus) skeleton at the Beneski Museum, taken by the author

American mastodon (Mammut americanum) at the Beneski Museum, taken by the author

 

Close-up of the American mastodon mandible at Beneski Museum, taken by the author. The lower tusk on this mastodon surprised me, and I spoke about this with Museum Educator, Fred Venne.  Conversations on Twitter prompted very interesting comments by @maxthemastodon from the Western Science Center, @dr_mastodonna (Dr. Katy Smith) and @chriswidga (Dr. Chris Widga).  It is important to note that this mastodon is comprised of components from at least two or more different mastodons.

 

Asking whether I could take pictures in the museum is how I first met Fred Venne, a tall, gracious man who walked toward me the moment he saw that I had questions.
I had never previously met a Museum Educator in person. Fred has now set the bar exceedingly high. It seems artful, his ability to share knowledge and offer insight, yet step away and enable someone to learn on one’s own—a very considerate balance. I marveled at this, just as I marveled at everything around me.

 

Fossil Mammal Wall at the Beneski Museum, taken by the author

Images corresponding to the skeletons on the Fossil Mammal Wall at the Beneski Museum, taken by the author

A view between two of the three floors at the Beneski Museum, taken by the author; notice the hint of fossil footprint slabs a the bottom right.

Triceratops skull and Gryposaurus (a hadrosaur) skeleton at the Beneski Museum, taken by the author

Various images of the many trace fossils collected by Edward Hitchcock over his lifetime at the Beneski Museum, taken by the author

 

It was Fred who informed me of a nearby excavation site. Searching online in his office and writing down the address for me, he then called the owner of the site to make sure he knew I was coming.

(Fred also introduced me to a member of the team who discovered Tiktaalik and visiting scholar, Steve Gatesy. Dr. Gatesy very generously proceeded to explain a bit about his current research, picking up and showing me specimens of single fossil tracks. For a day in which my expectations were simply to see fossil footprints and maybe a handful of bone fossils, this was proving to be extraordinary.)

My GPS almost got it right. I pulled in to the driveway just short of the actual destination, the neighbors smiling and waving good-bye after explaining it was just down the road.

At first glance, Nash Dinosaur Tracks has the air of a campground. Situated in a rural area, one drives up a path to a large opening, surrounded by forest. There is a single building in the corner, a cozy construction with hand-made signs.

Entrance sign to Nash Dinosaur Tracks and Fossil Shop, taken by the author

Path leading into Nash Dinosaur Tracks and Fossil Shop, taken by the author

Nash Fossil Shop, taken by the author

Sign depicting Dilophosaurus, the type of dinosaur thought to produce the type of tracks in the area.  “Eubrontes” is a name coined by Edward Hitchcock to describe these tracks.  Image taken by the author.

Image of two types of tracks believed to be made by two different (as yet unknown) types of dinosaur, as defined by Edward Hitchcock: eubrontes and grallator.  Sign at Beneski Museum, image taken by the author.

 

I feel it’s important I mention two conflicting feelings I had when Fred first described Nash Dinosaur Tracks, an area of active excavation with a fossil shop: ambivalence and overwhelming enthusiasm.

I’m not a paleontologist.  I don’t even work in a museum. I’m still learning many of the very basics of paleontology. And I know that in this country, fossils found on personal land belong to the person who owns that land. I’ve read quite a bit about the sale of fossils throughout the world. I’ve communicated with paleontologists who have differing views on the subject.

It is enormously complicated.

Large, beautiful skeletons arrive on the market for auction, sold to those who can afford their extravagant prices and then lost to the general public.  Sometimes, those skeletons are donated to a museum (or sold at a lower price). But in some places, the sale of important fossils means survival for those who sell them, a much different type of economic exchange. The biggest lightning rod right now is the sale of ivory, a turbulent conflict that affects both human and elephant lives, and extends into the sale of mammoth tusks.

Do fossils belong to the general public?  And if so, what public? (Country of origin? International groups?) Do museums or scientists have a right to them above all?

I don’t have answers.

But I do know that I cringe every time I read about fossils being sold, and this colors my perspective on the sale of any fossil any where.  Even on personal land, such as that of Kornell Nash.

So it was with mixed feelings that I walked into the fossil shop and called out, “Hello?”

View inside Nash Fossil Shop, taken by the author

Examples of fossils for sale, some under $100, some $3000 in the shop; image taken by the author

Kornell Nash, holding a fossil footprint on its side to display the layers of rock; image taken by the author

 

Kornell Nash appeared and introductions were made. He seemed a very gentle, unassuming man.  I learned later that this had been his day off; he had, in fact, just awoken from a nap.  But he mentioned none of that initially.  When I asked about the quarry, he indicated where it was, pointing to a door leading behind the shop.

“Feel free to look around,” he said and disappeared.

Stone outside of the door leading from the fossil shop to the quarry.  Can you find the fossil tracks?  (According to Kornell Nash, this stone was obtained by his father, Carlton Nash, from a different location.) Image taken by the author.

 

The word “quarry” in my mind conjures enormous stone and cavernous holes.  This was not such a place.  As I eagerly walked on a pine needle-strewn path, I kept expecting something bigger, something huge. Something to match my expectations of a place that had produced fossil footprints for decades.

What I came upon was a modest outcrop on an incline.

 

View of the fossil quarry from the path, taken by the author

View of the entire quarry, looking up, taken by the author

 

As I got closer, something crunched under foot.  I looked around me and saw bits of shale everywhere and I panicked.  Was I crushing fossil footprints?  Shale littered the ground; there was no where to walk without stepping on it, so I continued….gingerly.

Kornell had indicated there were large footprints across the top of the stone, but I didn’t see anything at first.  It wasn’t until I literally stepped upon the stone outcrop that I found them.

 

Example of an area of stone cut out by Kornell Nash, taken by the author

Segments of shale detritus that lines the back of the quarry, taken but the author

One of the many fossil footprints in the quarry, taken by the author

 

This was my first experience with fossils in-situ.  More importantly, this was my first experience actually touching the evidence of the life of an extinct creature.  While I love fossil skeletons, there was something much more significant–something inordinately more meaningful–in seeing where an actual dinosaur had STEPPED. And it is no exaggeration to say that putting my fingers into these footprints was the closest thing to a spiritual moment for me.

This, from private land with a fossil shop. Not from a museum, my normal haven and revered institution, but from the very thing that caused my self-righteousness.

I thought about this when I eventually walked back to the shop.

Newspaper articles of Nash Dinosaur Tracks (formerly known as “Dinosaurland”) and Kornell Nash on a wall in the fossil shop, images taken by the author

Pictures of Edward Hitchcock and Dr. Mignon Talbot–a paleontologist from Mount Holyoke College who discovered Podokesaurus in 1911. Kornell Nash’s dad, Carlton, corresponded with Dr. Talbot. Image taken by the author.  

 

There is so much history to the place, in and around the fossil shop.  Echoes of it hang on the walls, yellowed newspaper articles with edges curling and wrinkled.  Letters are tacked to a post.

Looking later on the Nash Dinosaur Tracks website, I was surprised to learn that Carlton (and George) Nash purchased the land in 1939 for $85.  Carlton Nash–Kornell’s father–is mentioned in the book “Bones for Barnum Brown” by Roland T. Bird.  Bird describes his visit with the family and seeing the fossilized remnants of what Carlton believed was an animal lying or sitting down.

Image of a picture of the fossilized trace of an animal lying or sitting down, according to Carlton Nash; picture of this picture taken by the author at the Nash Fossil Shop. This was described in a book by Roland T. Bird.

Image of that actual fossil with a slab of tracks above it in the fossil shop; image taken by the author

 

He communicated with numerous well-known scientists, including Dr. Mignon Talbot of Mount Holyoke College, discoverer of the Podokesaurus.  He donated a section of tracks to what is now known as Clarke Schools for Hearing and Speech.  A response was sent from Grace Coolidge, the wife of former US president, Calvin Coolidge.

Carlton Nash passed away in 1997.  Kornell Nash has been the owner since.

I asked him if he shared his father’s passion for paleontology and geology.

“In a different way,” he emailed back. “I really enjoyed the travel growing up.  We traveled all over the United States at a time many of my friends didn’t even get out of the Northeast. In a way, dinosaurs are quite common to me. Doesn’t everyone’s father dig dinosaur tracks?”

Kornell Nash describing the detail of a footprint in his fossil shop, taken by the author

 

I had a long way to drive home, and it was a beautiful drive on a beautiful day.  Autumn in New England means brisk air, pumpkins on the side of the road, corn stalks decorating porches. My head churned with what I’d experienced.  I pondered the people I’d met and the things I’d witnessed.

It was but one page in the chapters of my life thus far, but this page, I savor.

A fossil footprint path in the quarry behind Nash Fossil Shop; image taken by the author

———-

Fred Venne made what might have been a good trip to the Beneski Museum one that was an absolutely outstanding adventure.  He is a superb ambassador for Amherst College, and I am profoundly grateful for his thoughtfulness.

A sincere thank you to Dr. Steve Gatesy for his time and his willingness to share details about his current research!

I am indebted to Kornell Nash for letting me explore his fossil quarry alone and for being able to actually touch fossil footprints in-situ.  I am grateful for his willingness to connect with me and share more insight into his father’s communication.

I am sincerely thankful to Amherst College for making the Beneski Museum open to the public (and for free!) It is a marvelous museum, and I encourage all interested to make the trip to see it!

And I remain consistently grateful (and awed) by the generosity of so many paleontologists who have helped me as I learn more about their field. You are all extraordinary!

Exciting New Info About Mastodons and Humans – Yukon Paleontology, Part 1

“Good morning!”

It’s not just a greeting; it sounds like a proclamation.

The voice on the other end of the phone is deep, melodic, and—as our conversation progresses—punctuated with moments of laughter.  We have been discussing paleontology in the Yukon, and with each new detail, I begin to wonder why this territory is not making regular international headlines.

Dr. Grant Zazula’s work is fascinating, and it is neither a short phone call nor the only communication we’ve exchanged. And yet, it is all that I can do not to encourage him to keep going, long after social decorum dictates that he has been more than generous with his time.

[image of Dr. Grant Zazula with a mastodon ulna, part of the Earl Bennett mastodon, courtesy of the Government of Yukon]

Dr. Zazula is the Yukon paleontologist, a job that has only existed since 1996. His own tenure began in 2006.  With an office in Whitehorse, the capital of the territory, his work oversees an expanse of Canada that abuts Alaska.  It is a land of dramatic beauty, where colors dance in the sky and mountains tower in silent grandeur.

Embed from Getty Images

His most recent paper, co-written with 14 other people, made news throughout the world and continues to attract media attention. In it, the scientists present data that completely overturns previously believed information about extinct animals and the impact that humans may or may not have had upon their survival.

“[T]here were two radiocarbon dates in the literature from Yukon mastodons,” he explained in an email. “One that was ~18,000 and the other 24,000 years old.”

“Based on analysis of the paleoecology, that was a time when steppe-tundra grasslands covered Alaska, Yukon and Beringia. There were probably no trees, few shrubs and almost no standing water. It was very cold and, especially, dry. This seemingly is not good mastodon habitat. So either the dates were incorrect, or our understanding of mastodon ecology, behavior and adaptations need[s] to be revised.”

Various species of mastodon once existed throughout the world.  Although their fossils look elephantine, they are not believed to be direct ancestors of today’s elephants. They are, however, part of the same umbrella mammalian group: the Proboscidea (so-named for the trunks possessed by many—but not all–of their members).  In North America, that group contained the American mastodon (Mammut americanum), the woolly mammoth (Mammuthus primigenius), and the Columbian mammoth (Mammuthus columbi).

 [image of the Cohoes mastodon, NY State Museum, Albany; taken by the author]

Mastodons tended to have straighter tusks and were shorter than their mammoth cousins. They also ate hardier vegetation, food that required a much different tooth structure than mammoths.

[image of mastodon tooth, courtesy of the Indiana State Museum]

[image of mammoth tooth, courtesy of the Indiana State Museum; for more info about the differences between mammoths and mastodons, see this post.]

Parts of Siberia, Alaska and the Yukon were once connected in an area known as “Beringia.”  The Bering Strait did not yet exist, enabling animals and eventually the first humans to cross into our continent.  It is believed that humans arrived in what is now North America about 14,000 years ago.

And this is where the research of Dr. Zazula and his colleagues becomes particularly important.

Prior to their paper, one theory to mastodon extinction laid the blame upon first humans: it was proposed that they overhunted these animals.

Sampling 36 fossils and presenting 53 new radiocarbon dates, Dr. Zazula and his colleagues found that mastodons within Alaska and the Yukon were much, much older than the originally published dates.  In other words, their research suggests that mastodons from what was once Eastern Beringia were no longer present when the first humans appeared.

The path to this remarkable research did not happen overnight.

The foundation appears to have been laid by two different events: by the chance meeting of Dr. Zazula and a gold miner, and later, by the PhD work of a graduate student.

If one reads the acknowledgements on the aforementioned paper, Dr. Zazula references Earl Bennett as both the donor of a partial mastodon skeleton and his inspiration to learn more about mastodons within the Yukon.

“Earl is a great Yukoner,” Dr. Zazula wrote when asked about this. “He mined for gold underground in the winters with a pick and shovel, decades ago. He worked on big gold dredge machines. And, he loves paleontology.

“While mining, he made collections of Ice Age bones that were just left around the mining camp or were encountered while mining. He eventually amassed an amazing collection.

“In the early 1970’s a gold dredge on Bonanza Creek hit a skeleton of a mastodon. An incredibly rare find! Someone collected it and was looking to sell it. So, Earl bought the skeleton just to make sure that it never left the Yukon. He had it in his garage for decades.

“One day a mutual friend introduced me to him in a coffee shop, about a year after starting my job [as the Yukon paleontologist]. He said that he had a mastodon skeleton and wanted me to see it. I ‘corrected’ him, saying that it was more likely a mammoth, because we almost never find mastodons in the Yukon. He assured me he know the difference and said he would see me tomorrow at my office.

“The next day he backed his truck up and in it was a partial mastodon skeleton. I couldn’t believe it. There were several postcranial bones, some vertebra, scapula, parts of the skull and parts of the mandible with teeth. It was amazing. I wanted to find out how old it was, and that was one of the inspirations for this project. Earl is a good friend now and big supporter of our research.”

[Paleontologist Grant Zazula with a partial American mastodon (Mammut Americanum) skeleton found on Bonanza Creek and donated to the Yukon fossil collection by Earl Bennett, from Ice Age Klondike, courtesy of the Government of Yukon]

That partial skeleton was indeed one of the many fossils sampled for the paper.

Dr. Jessica Metcalfe, one of the co-authors, also prompted this research when conducting work for her PhD.

“[S]he was doing a project looking at stable isotope ecology of mammoths and mastodons in various places in North America,” said Dr. Zazula.

[image of Dr. Jessica Metcalfe with mammoth bone, courtesy of the Government of Yukon]

Her work included Yukon fossils that were sent to the lab at the University of Arizona to be radiocarbon dated.   Those dates turned out to be older then 50,000 years old.

“So that’s what got me thinking,” he continued, “‘well, maybe those original published dates are wrong.’”

“The first step was to re-date [the specimens that had produced the original published dates]. The new dates turned out to be >50,000 years. So we knew there was a problem with the previous dates. We figured then we should date as many as we could get our hands on.”

This lead Dr. Zazula to connect with Dr. Ross McPhee, another co-author.

“I got in touch with him early because he oversees collections at the American Museum of Natural History, [and] he has a big interest and lots of experience working on Ice Age extinctions. [H]e’s an excellent writer and really kind of kept us going with some of the writings. He was really integral to keeping things together.”

The paper eventually involved a total of 15 people.

“I feel pretty strongly that if you worked on it and contributed to it, then you should be considered an author,” Dr. Zazula stated.  “So it ended up being a long list.”

One of the first aspects their paper addresses is the reason behind why the original published dates are incorrect: the dating analyses were contaminated by fossil conservation methods.

“Humic acids in soils can be absorbed by the bones and teeth and chemically bind themselves to the collagen,” he wrote, explaining further. “So, modern ‘young’ carbon in those acids basically contaminates the ‘old’ collagen in the ancient fossil. And, it can be tricky to remove.

“The same with consolidants in museums. Varnish, glue, and other substances to preserve fossils can be absorbed into the bone and chemically bind with the collagen in the bone. These substances probably contain young, modern carbon which messes up the radiocarbon dating measurements.”

When asked whether museums continue to use the same preservation products that contaminated the dates, he wrote, “Yes, for sure. The thing is now museums keep better records of what they use. Many of the fossils we dated were collected in the 1940’s or at least several decades ago. Museums were not that vigilant about keeping detailed records on those things then. Also, they seemed to put preservatives on everything. Now, at least if we know what was put on it, the chemistry can by developed to remove it. Most of the common preservatives now are soluble in alcohol or acetone and can be dealt with. The problem is when they are unknown.”

We discussed this further by phone.

“One thing about Alaska and the Yukon,” he said, “is that the Ice Age bones that come out of the ground are so well preserved because of the permafrost. In other localities, say, the deserts of the American Southwest or the Great Basin or the Plains, where bones have been out in the sun and [are] dry and hot, they [sometimes] fall apart really easily when they come out of the ground. They need to be glued and consolidated with these various types of museum products.

“So you kind of have to weigh the different values.

“Say if it’s a specimen that’s already been radiocarbon dated, and it starts to slowly disintegrate, well, then you kind of have to intervene or else you’re just going to end up with a box of dust and broken bone. You have to decide whether the importance is more with display or preservation of the morphology versus needing to radiocarbon date or other types of analysis.

“[Y]ou have to look at the pro’s and con’s of whether the sampling [for radiocarbon dating] will ruin the specimen or not, and what is the potential information that can be gained by doing it. To me, I feel that having a research collection [in the Yukon], it’s all about research and learning new things from these specimens.”

Ultimately, I wondered whether Dr. Zazula expected the results he and his colleagues uncovered.

“I wasn’t quite sure,” he answered. “I had the gut feeling that these previously published radiocarbon dates were probably wrong. It didn’t make a lot of sense ecologically to have mastodons living in the far North when it was seemingly habitat they couldn’t live in: habitat with grassland and cold, dry steppe tundra conditions, no trees and very few shrubs.

“But there [was] also a part in the back of my mind that thought, ‘well, if those [previously published dates] were right, that’s maybe even more interesting because they are telling us something about mastodons and their behavior and their adaptations that we didn’t know before.’”

————

It was a great honor and pleasure to connect with Dr. Grant Zazula! Not only patient with my myriad questions, he is an adept and fascinating ambassador for the Yukon. A Mammuthus columbi-sized thank you to him!

A Mammuthus columbi-sized thank you to Dick Mol, as well, who is the reason behind this post!

[image of Dick Mol with fossil horse skull, found near Dawson City, Yukon; courtesy of the Government of Yukon]

Yukon Paleontology Program: http://www.tc.gov.yk.ca/palaeontology.html

Articles and publication referenced:

• American mastodon extirpation in the Arctic and Subarctic predates human colonization and terminal Pleistocene climate change, Grant D. Zazula et al, Proceedings of the National Academy of Sciences of the United States of America (PNAS), vol. 111, no. 52, December 30, 2014
• Ice Age Klondike, by Grant Zazula and Duane Froese, Government of Yukon, 2011
• Nursing, weaning, and tooth development in woolly mammoths from Old Crow, Yukon, Canada: Implications for Pleistocene extinctions, Jessica Z. Metcalfe et al, Palaeogeography, Palaeoclimatology, Palaeoecology, Volume 298, Issues 3–4, 15 December 2010, Pages 257–270

 

Listen to Dr. Zazula discuss his paper on the CBC’s Quirks & Quarks: http://www.cbc.ca/radio/quirks/quirks-quarks-for-dec-6-2014-1.2864605/mastodons-made-an-early-exit-from-the-north-1.2864634

 

[REPOST] The Mammoth Site and Dr. Larry Agenbroad – Renowned Paleontologist

Ask Dr. Larry Agenbroad what his most exciting discovery as a paleontologist has been, and his response is: “Too many to select just one.”

He cites, among the top three, discoveries with which you might already be very familiar:

• the most complete pygmy mammoth skeleton found to-date,

• an 11,000 year-old bison kill site,

• and the Jarkov mammoth in Siberia.

These discoveries—like his work—are from all over the world.

(Image of Dr. Agenbroad and fossil replica, courtesy of Dr. Larry Agenbroad. If you, like me, thought this was a saber-toothed cat fossil, guess again! See the end of the post for more info*.)

Pygmy mammoths are the smallest of the known species, and their remains have been found on Wrangel Island (off of Russia) and on the Channel Islands (off of California). It is thought that their size evolved from their isolated existence on islands, an environment that would not be able to support multiple Columbian or woolly mammoths.

Dr. Agenbroad led the team that excavated the most complete pygmy mammoth skeleton yet found. A cast of the fossil can be seen at the Channel Islands National Park Visitor Center, and a replica of this fossil in-situ is in the Santa Barbara Museum of Natural History. The SBMNH’s website states that Dr. Agenbroad has found 66 more fossil sites on the islands.

Nebraska is home to the Hudson-Meng Bison Kill Site. Named after Bill Hudson and Albert Meng, who found it by accident in 1954, it eventually produced almost 600 separate bison fossils. These fossils represent a species of bison that does not exist today. Dr. Agenbroad began excavation here in the 1970’s. Different theories exist regarding why so many 11,000 year-old remains of the same species are in one place.

You can see Dr. Agenbroad in the Discovery Channel documentary, “Raising the Mammoth”. It details the discovery and research of the Jarkov mammoth in Siberia. Dr. Agenbroad is among other well-known paleontologists who worked together on this remarkable find: an enormous mammoth encased in ice. That documentary also gives you a peak into the Mammoth Site in Hot Springs, South Dakota, where he is the Chief Scientist and Site Director.

Recently accredited by the American Alliance of Museums, the Mammoth Site houses the largest collection of mammoth fossils in the United States. It is open to the public year-round.

Their website lists that they recently found the 61st mammoth fossil this summer; 58 of which are Columbian mammoths, 3 are woolly mammoths.

Woolly mammoths may dominate mainstream imagination, but the species that lived throughout the U.S. was actually the largest (and possibly the least hairy) representative of that species: the Columbian mammoth.

The Mammoth Site, a growing museum on 8.5 acres of land, is built over the initial excavation area. And that area was originally intended as part of a housing development. Construction came to a halt in 1974 when mammoth fossils were found.

Joe Muller, COO/Business Manager of the museum, describes the initial structure built in 1975 as a modest plywood construction. An addition was made to that structure in 1976 and 1978.

“That [addition] remained over part of the site so people could come in and look a little bit at some of the fossils,” he said in a phone interview.

“[Researchers] would excavate outside (there was a self-imposed hiatus from excavating for 1980-1982 and 1984-1985 until a building could be constructed over the site) until in 1986, the building was built over the sinkhole area. Then in 1990 we enclosed a lobby area with a gift shop.”

Today, there is an additional 4000 square feet of enclosed exhibit space, plus 8,000 square feet for laboratory, bone storage, research library, offices, bathrooms and storage (which opened in May 2001).

And–to give readers an additional sense of the size of the museum space–there is a crane.

“We have a crane in the sinkhole area,” he continued, “so that we can remove the fossils, take them to the ‘mammoth elevator’, and then take them to the basement to the laboratory work on.”

The sinkhole is the reason Hot Springs has such a wealth of fossils. As described both on the museum’s website and in the acclaimed book by Adrian Lister and Paul Bahn (Mammoths: Giants of the Ice Age), the area known as “the sinkhole” was created about 26,000 years ago. It was a 65-foot-deep pond framed by steep banks, with an even deeper section through which flowed warm water. Warm water and vegetation are believed to be the temptations that caused mammoths to venture into the pond. Getting out of that pond—or rather, the inability thereof–is believed to have been the cause of their death.

The many fossils that remain today—mostly young male mammoths—were eventually covered and preserved by mud and sediment over thousands of years. A number of these fossils remain in-situ and available to the public at the Mammoth Site. Excavation within the site continues each year, and it is an opportunity for which one can apply—paleontological background or not. Muller advises that one can apply “to come and excavate for five days with Roads Scholars (May & October), then EarthWatch volunteers come for two two-week sessions; basically the month of July.” Amongst the Ice Age fossils found are camel, llama, prairie dog, a giant short-faced bear, wolf, and numerous invertebrates.

The book Mammoths: Giants of the Ice Age lists the surprising fact that mammoth hyoid bones and bile stones have been recovered here.

Dr. Agenbroad explained that “a hyoid bone is a set (5) of bones that support the tongue. Often only one of the set is found.” When asked how something so seemingly small such as a bile stone could be found and identified, he said that is “a non-osteological specimen”, and that they use “chemical analyses to identify them, comparing and contrasting them to modern elephant bile stones.”

Dr. Adrian Lister, one of the authors of the aforementioned book, is listed as one of the former “Visiting Scholars” to the Mammoth Site. Designed and implemented by Dr. Agenbroad, the Visiting Scholar program invites researchers to study at the site.

“I wanted to ‘cross-pollinate’ ideas, methods, and theories with international experts,” wrote Dr. Agenbroad in an email. In response to whether other sites engage in similar activities, he continued, “It is rare for other sites to invite and support a visiting scholar (usually due to budget restrictions).”

The impressive list of “Visiting Scholars” also includes, among others, Adriana Torres of Mexico; Dr. Laura Luzi of Italy; Dr. Daniel Fisher (now of the University of Michigan, one of the many researchers who worked on “Lyuba”, the best preserved baby mammoth found to-date, and mammoth-tusk expert); Dick Mol of the Netherlands;  Dr. Evgeny Maschenko, Dr. Alexei Tikhonov and Dr. Gennady Baryshnikov of Russia; Dr. Ralf Kahlke of Germany; and Dr. Jim Burns of Canada.

In terms of tourists, approximately 100,000 people visit the Mammoth Site each year from all over the world.

“Our town is about 3700 people,” Muller said, referring to Hot Springs, SD, “so when we bring in 100,000 visitors a year, it’s a big economic impact for the city.”

From the United States, visitors from Minnesota and Colorado top the list (visitors from South Dakota itself come in third!), but people from as far as South Africa, Korea, and Australia—among so many other foreign countries—also travel to the site.

The Mammoth Site received accreditation by the American Alliance of Museums in October of 2013.

“We are in the top 6% of museums in the United States, as only about 5.8% of the estimated 17,500 museums are accredited.”

The accreditation process is apparently a lengthy process, and not every museum is successfully accredited upon their initial application. Policies regarding everything from the artifacts and exhibits (its “collections”) to its financial policies are reviewed and evaluated. The Mammoth Site, Muller stated with well-deserved enthusiasm, “made it the first time!”

“We have a $2.2 million major gift campaign going on now,” Muller continued. “$1.6 million is for a ‘Learning Center’, which includes a couple of theatres and a kind of a gathering area. We are planning a bid letting in August and construction to start in October, with a May 2015 opening date.”

The website offers a “buy-a-brick” program as part of that campaign. It is clear that the growth of this museum is–in no small part–a result of the dedication of everyone who works at and is involved with the Mammoth Site. Muller attributes that to a close-knit community within the museum.

“We’re pretty much like a family, and that’s what the reviewers with American Alliance of Museums said that they were really impressed with: how the staff gets along and works together.”

——————————————————————————

*Dr. Agenbroad is pictured with a short-faced bear replica.

The Mammoth Site: http://www.mammothsite.com/

You can apply to excavate at the Mammoth Site! http://www.mammothsite.com/earthwatch.html OR http://www.mammothsite.com/elderhostel.html

Buy-a-brick to help the Mammoth Site campaign! http://mammothsite.pinnaclecart.com/index.php?p=product&id=1064

Pygmy Mammoth, Channel Islands National Park: http://www.nps.gov/chis/historyculture/pygmymammoth.htm

Pygmy Mammoth, Santa Barbara Natural Museum of History: http://www.sbnature.org/exhibitions/199.html

Latin names of mammoth species mentioned:

Pygmy mammoths = Mammuthus exilis

Woolly mammoths = Mammuthus primigenius

Columbian mammoths = Mammuthus columbi

(Earlier post with Dr. Dan Fisher: https://mostlymammoths.wordpress.com/2013/09/10/mammoth-article-qa-dr-daniel-fisher-renowned-paleontologist/)

A Mammuthus columbi-sized THANK YOU to Dr. Larry Agenbroad and Joe Muller for their time, their generous insight, and their work at the Mammoth Site! An equally large thank you to Presston Gabel, Diana Turner and for all who are involved with the work in that museum!

The Mammoth Site and Dr. Larry Agenbroad – Renowned Paleontologist

Ask Dr. Larry Agenbroad what his most exciting discovery as a paleontologist has been, and his response is: “Too many to select just one.”

He cites, among the top three, discoveries with which you might already be very familiar:

• the most complete pygmy mammoth skeleton found to-date,

• an 11,000 year-old bison kill site,

• and the Jarkov mammoth in Siberia.

These discoveries—like his work—are from all over the world.

(Image of Dr. Agenbroad and fossil replica, courtesy of Dr. Larry Agenbroad. If you, like me, thought this was a saber-toothed cat fossil, guess again! See the end of the post for more info*.)

Pygmy mammoths are the smallest of the known species, and their remains have been found on Wrangel Island (off of Russia) and on the Channel Islands (off of California). It is thought that their size evolved from their isolated existence on islands, an environment that would not be able to support multiple Columbian or woolly mammoths.

Dr. Agenbroad led the team that excavated the most complete pygmy mammoth skeleton yet found. A cast of the fossil can be seen at the Channel Islands National Park Visitor Center, and a replica of this fossil in-situ is in the Santa Barbara Museum of Natural History. The SBMNH’s website states that Dr. Agenbroad has found 66 more fossil sites on the islands.

Nebraska is home to the Hudson-Meng Bison Kill Site. Named after Bill Hudson and Albert Meng, who found it by accident in 1954, it eventually produced almost 600 separate bison fossils. These fossils represent a species of bison that does not exist today. Dr. Agenbroad began excavation here in the 1970’s. Different theories exist regarding why so many 11,000 year-old remains of the same species are in one place.

You can see Dr. Agenbroad in the Discovery Channel documentary, “Raising the Mammoth”. It details the discovery and research of the Jarkov mammoth in Siberia. Dr. Agenbroad is among other well-known paleontologists who worked together on this remarkable find: an enormous mammoth encased in ice. That documentary also gives you a peak into the Mammoth Site in Hot Springs, South Dakota, where he is the Chief Scientist and Site Director.

Recently accredited by the American Alliance of Museums, the Mammoth Site houses the largest collection of mammoth fossils in the United States. It is open to the public year-round.

Their website lists that they recently found the 61st mammoth fossil this summer; 58 of which are Columbian mammoths, 3 are woolly mammoths.

Woolly mammoths may dominate mainstream imagination, but the species that lived throughout the U.S. was actually the largest (and possibly the least hairy) representative of that species: the Columbian mammoth.

The Mammoth Site, a growing museum on 8.5 acres of land, is built over the initial excavation area. And that area was originally intended as part of a housing development. Construction came to a halt in 1974 when mammoth fossils were found.

Joe Muller, COO/Business Manager of the museum, describes the initial structure built in 1975 as a modest plywood construction. An addition was made to that structure in 1976 and 1978.

“That [addition] remained over part of the site so people could come in and look a little bit at some of the fossils,” he said in a phone interview.

“[Researchers] would excavate outside (there was a self-imposed hiatus from excavating for 1980-1982 and 1984-1985 until a building could be constructed over the site) until in 1986, the building was built over the sinkhole area. Then in 1990 we enclosed a lobby area with a gift shop.”

Today, there is an additional 4000 square feet of enclosed exhibit space, plus 8,000 square feet for laboratory, bone storage, research library, offices, bathrooms and storage (which opened in May 2001).

And–to give readers an additional sense of the size of the museum space–there is a crane.

“We have a crane in the sinkhole area,” he continued, “so that we can remove the fossils, take them to the ‘mammoth elevator’, and then take them to the basement to the laboratory work on.”

The sinkhole is the reason Hot Springs has such a wealth of fossils. As described both on the museum’s website and in the acclaimed book by Adrian Lister and Paul Bahn (Mammoths: Giants of the Ice Age), the area known as “the sinkhole” was created about 26,000 years ago. It was a 65-foot-deep pond framed by steep banks, with an even deeper section through which flowed warm water. Warm water and vegetation are believed to be the temptations that caused mammoths to venture into the pond. Getting out of that pond—or rather, the inability thereof–is believed to have been the cause of their death.

The many fossils that remain today—mostly young male mammoths—were eventually covered and preserved by mud and sediment over thousands of years. A number of these fossils remain in-situ and available to the public at the Mammoth Site. Excavation within the site continues each year, and it is an opportunity for which one can apply—paleontological background or not. Muller advises that one can apply “to come and excavate for five days with Roads Scholars (May & October), then EarthWatch volunteers come for two two-week sessions; basically the month of July.” Amongst the Ice Age fossils found are camel, llama, prairie dog, a giant short-faced bear, wolf, and numerous invertebrates.

The book Mammoths: Giants of the Ice Age lists the surprising fact that mammoth hyoid bones and bile stones have been recovered here.

Dr. Agenbroad explained that “a hyoid bone is a set (5) of bones that support the tongue. Often only one of the set is found.” When asked how something so seemingly small such as a bile stone could be found and identified, he said that is “a non-osteological specimen”, and that they use “chemical analyses to identify them, comparing and contrasting them to modern elephant bile stones.”

Dr. Adrian Lister, one of the authors of the aforementioned book, is listed as one of the former “Visiting Scholars” to the Mammoth Site. Designed and implemented by Dr. Agenbroad, the Visiting Scholar program invites researchers to study at the site.

“I wanted to ‘cross-pollinate’ ideas, methods, and theories with international experts,” wrote Dr. Agenbroad in an email. In response to whether other sites engage in similar activities, he continued, “It is rare for other sites to invite and support a visiting scholar (usually due to budget restrictions).”

The impressive list of “Visiting Scholars” also includes, among others, Adriana Torres of Mexico; Dr. Laura Luzi of Italy; Dr. Daniel Fisher (now of the University of Michigan, one of the many researchers who worked on “Lyuba”, the best preserved baby mammoth found to-date, and mammoth-tusk expert); Dick Mol of the Netherlands;  Dr. Evgeny Maschenko, Dr. Alexei Tikhonov and Dr. Gennady Baryshnikov of Russia; Dr. Ralf Kahlke of Germany; and Dr. Jim Burns of Canada.

In terms of tourists, approximately 100,000 people visit the Mammoth Site each year from all over the world.

“Our town is about 3700 people,” Muller said, referring to Hot Springs, SD, “so when we bring in 100,000 visitors a year, it’s a big economic impact for the city.”

From the United States, visitors from Minnesota and Colorado top the list (visitors from South Dakota itself come in third!), but people from as far as South Africa, Korea, and Australia—among so many other foreign countries—also travel to the site.

The Mammoth Site received accreditation by the American Alliance of Museums in October of 2013.

“We are in the top 6% of museums in the United States, as only about 5.8% of the estimated 17,500 museums are accredited.”

The accreditation process is apparently a lengthy process, and not every museum is successfully accredited upon their initial application. Policies regarding everything from the artifacts and exhibits (its “collections”) to its financial policies are reviewed and evaluated. The Mammoth Site, Muller stated with well-deserved enthusiasm, “made it the first time!”

“We have a $2.2 million major gift campaign going on now,” Muller continued. “$1.6 million is for a ‘Learning Center’, which includes a couple of theatres and a kind of a gathering area. We are planning a bid letting in August and construction to start in October, with a May 2015 opening date.”

The website offers a “buy-a-brick” program as part of that campaign. It is clear that the growth of this museum is–in no small part–a result of the dedication of everyone who works at and is involved with the Mammoth Site. Muller attributes that to a close-knit community within the museum.

“We’re pretty much like a family, and that’s what the reviewers with American Alliance of Museums said that they were really impressed with: how the staff gets along and works together.”

——————————————————————————

*Dr. Agenbroad is pictured with a short-faced bear replica.

The Mammoth Site: http://www.mammothsite.com/

You can apply to excavate at the Mammoth Site! http://www.mammothsite.com/earthwatch.html OR http://www.mammothsite.com/elderhostel.html

Buy-a-brick to help the Mammoth Site campaign! http://mammothsite.pinnaclecart.com/index.php?p=product&id=1064

Pygmy Mammoth, Channel Islands National Park: http://www.nps.gov/chis/historyculture/pygmymammoth.htm

Pygmy Mammoth, Santa Barbara Natural Museum of History: http://www.sbnature.org/exhibitions/199.html

Latin names of mammoth species mentioned:

Pygmy mammoths = Mammuthus exilis

Woolly mammoths = Mammuthus primigenius

Columbian mammoths = Mammuthus columbi

(Earlier post with Dr. Dan Fisher: https://mostlymammoths.wordpress.com/2013/09/10/mammoth-article-qa-dr-daniel-fisher-renowned-paleontologist/)

A Mammuthus columbi-sized THANK YOU to Dr. Larry Agenbroad and Joe Muller for their time, their generous insight, and their work at the Mammoth Site! An equally large thank you to Presston Gabel, Diana Turner and for all who are involved with the work in that museum!