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.

Advertisements

Fossil Discoveries in Niger with Dr. Ralf Kosma

“I often wrapped wet clothes around my head in order to cool my brain during digging.”

Dr. Ralf Kosma, curator of paleontology at the State Museum of Natural History in Braunschweig, Germany, was part of an international team that excavated fossils in Niger during the late 2000s.

“[T]he heat was incredible,” he wrote in an email, “especially in April/May. Usually I can stand the heat, and I did in Niger, but many colleagues in our team (both German and Nigerien) became ill as a result of the horrifying heat.”

Embed from Getty Images

 

Much of the country—particularly in the northern region, which is where Dr. Kosma and team excavated–is in the Sahara desert.  In an area devoid of many trees (hence, shade), where temperatures are regularly above 100 degrees Fahrenheit and where water is in short supply, heat is a crucial concern.

Word of a large dinosaur bone traveled from Niger to Germany by way of Edgar Sommer, both a friend of State Museum of Natural History Director Dr. Ulrich Joger and someone with ties to an educational organization in Niger.

Paleontologists from the museum worked together with those from the local Aderbissinat community: a people comprised—like the country (and the continent!) entire—of various cultures.  Among those cultures are the Tuareg, the Hausa, and the Fulani people.

“This was organized,” Dr. Kosma wrote, describing who they hired from the community, “by Ahmad Bahani, our local Tuareg partner, and Mohammed Echika, Tuareg Chief and Mayor of the village Tadibene…”

Photo courtesy of Dr. Ralf Kosma

Photo courtesy of Dr. Ralf Kosma

 

Photo courtesy of Dr. Ralf Kosma

Photo courtesy of Dr. Ralf Kosma

Back row from left to right: Sidi Bahani, Dr. Ralf Kosma (Braunschweig), Abdul Khader, Achim Ritter (Braunschweig, technican and artist), Prof. Dr. Ulrich Joger (Director of our museum, the State Museum of Natural History in Braunschweig, Germany), Hanna Joger (daughter of Ulrich Joger) from Darmstadt, Germany, Jannis Joger (with colorful turban; son of Ulrich Joger from Darmstadt, Germany), Fritz J. Krüger (Braunschweig, paleontological volunteer of the SNHM), Michel Rabe (with hat, Braunschweig, also museum volunteer), Azziz Bahani.

Front row from left to right: Moussa, Aghali, Abdul Raman, Mohammed, Dr. Alexander Mudroch (Paleontologist, Hannover, Germany), Jörg Faust (camera assistant, from Berlin)

Picture was taken in spring 2007 in Aderbissinat at our field camp at the Spinophorosaurus site.

Photo and caption courtesy of Dr. Ralf Kosma

 

Proud Tuareg camel riders celebrating the “Festival of Salt” in Agadez, 2007. Photo and caption courtesy of Dr. Ralf Kosma

Photo courtesy of Dr. Ralf Kosma

 

They camped in the field—using a campfire to cook food, some of it local, some of it brought with them in tins from Germany.  Along with the heat, they dealt with several sandstorms.

“It was peeling our skin. One was really hard and we took shelter in our laboratory truck.”

But they were also excavating at a time when civil war broke out within the country.

“We were,” he wrote, “protected by the army and by Mayor Mohammed Echika.”

 

“We encountered snakes, scorpions, a monitor lizard, geckoes, skinks and a variety of toads, birds and mammals. Due to our director being a herpetologist we were well prepared against bites of venomous snakes. At night we went snake hunting with [flashlights].” – Dr. Ralf Kosma.  Caption and photo courtesy of Dr. Ralf Kosma

 

Between 2005 and 2008, the team excavated several places near Aderbissinat.  Petrified wood fossils of Taxodioideae amongst other conifers, fossil crocodile teeth, and ganoid fish scales indicate that the arid area of today was actually swampy and wet in the Jurassic.  Perhaps their most exciting finds: a partial sauropod skeleton and 5 individual theropod trackways.

Excavation of the sauropod took place in 2007; removal of the fossil occurred in 2008, when it was taken to the State Museum of Natural History in Braunschweig. Now on permanent display in its dinosaur hall, the partial sauropod is 8 meters long: 37 caudal vertebrae and 5 fused sacral vertebrae.

Specimen 1 from Spinophorosaurus nigerensis [a different fossil and species from the one discussed in this blog], directly after excavating in November 2006. The specimen was almost completely articulated. This specimen was later taken by a Spanish team and brought to the paleontological museum of Elche in the vicinity of Alicante in Spain. The person on the picture is Ahmed Bahani, our Tuareg coordinator. Photo and caption courtesy of Dr. Ralf Kosma

Photo courtesy of Dr. Ralf Kosma

Photo courtesy of Dr. Ralf Kosma

Fossilized tree trunk on top of the cliffs of Tiguidit. 2008. Probably Cretaceous. (Attention! If you thought this is a sauropod vertebrae – it is not!) Photo and caption courtesy of Dr. Ralf Kosma

 

Further study by Dr. Emanuel Tschopp and team indicates the sauropod might be Jobaria tiguidensis.  Research undertaken by Florian Witzmann, Oliver Hampe, Bruce Rothschild, Ulrich Joger, Ralf Kosma, Daniela Schwarz and Patrick Asbach reveals that the poor Jobaria may have suffered from a painful bone pathology.

There is a debate—since soft-tissues rarely fossilize—about what existed between vertebrae in dinosaurs.  What connected the bones, of what did that connection consist, and how exactly did it make that connection to the bone?  We don’t know.  But research gives us insightful clues.

Dr. Witzmann and team, in their 2016 paper (Subchondral cysts at synovial vertebral joints as analogies of Schmorl’s nodes in a sauropod dinosaur from Niger), looked to the work of Steve Salisbury and Eberhard Frey.  Comparing extant and extinct crocodile vertebrae with that of mammalian vertebrae, they found evidence pointing to synovial joints in dinosaurs.  This is in direct contrast to the discovertebral junctions known in mammals. The two are shaped differently, enable different range of movement within the joints, and are comprised of different substances.

Ultimately, we don’t know for certain whether dinosaurs had a discovertebral junction or whether they had synovial joints. This is important because these distinctions impact our understanding of the Nigerien sauropod’s pathology.

A 1978 paper by Resnick and Niwayama suggests subchondral cysts near synovial joints result in the same pathology as “Schmorl’s nodes,” a pathology that presents as holes or lesions in the bone. This is particularly interesting, as, thus far, only extant mammals (animals with discovertebral junctions) have exhibited traces of Schmorl’s nodes. (Only one case of possible Schmorl’s nodes in a reptile was published in 2001.)

Schmorl’s Nodes from Wikipedia credit: By J. Lengerke 22:47, 12. Jan. 2010 (CET) (Praxis Dr. Jochen Lengerke) [CC BY-SA 3.0 (https://creativecommons.org/licenses/by-sa/3.0), CC BY-SA 3.0 de (https://creativecommons.org/licenses/by-sa/3.0/de/deed.en) or GFDL (http://www.gnu.org/copyleft/fdl.html)%5D, via Wikimedia Commons

 

CT scanning provided further insight into the sauropod vertebrae.  While the team wondered whether the holes might be the work of ancient insects, this was discounted because there are no traces of insect mandibles and the holes are too large.  As the vertebrae were articulated when they were discovered, it was determined the space was too small for tiny mammals to make any impact postmortem.  The team therefore suggests that the lesions on the sauropod vertebrae are subchondral cysts, perhaps an analog to Schmorl’s nodes.

 

Photo courtesy of Dr. Ralf Kosma

 

Photo courtesy of Dr. Ralf Kosma

Photo courtesy of Dr. Ralf Kosma

Preparing the ribs of Spinophorosaurus nigerensis, specimen 2, for transportation in spring 2007. Aderbissinat. Constructing plaster jackets. Persons from left to right: Tuareg helper Aghali, our museum volonteer Fritz J. Krüger (from Braunschweig, Germany), and me (Dr. Ralf Kosma, Staatliches Naturhistorisches Museum, Braunschweig, Germany). Photo and caption courtesy of Dr. Ralf Kosma

 

The fossil footprints—120 tracks thus far, all of which remain in-situ in Niger—were discovered in 2007 and 2008.  Researchers from the Archaeological Institute of the University Abdou Moumouni (Institut de Recherches en Sciences Humaines, Niamey) and paleontologists from the German Museum worked together to both find and study them (Alexander Mudroch, Ute Richter, Ulrich Joger, Ralf Kosma, Oumarou Idé, Abdoulaye Maga in their 2011 paper: Didactyl Tracks of Paravian Theropods (Maniraptora) from the ?Middle Jurassic of Africa).

Casts and molds were taken of the tracks, of which, it was determined there are 5 distinct trackways.  Their unique shape gave rise to a new ichnotaxon: Paravipus didactyloides.

Although found in an area believed to be by a stream or lake during the Jurassic, the footprints are not believed to be swim traces.  Nothing in the sediment supports this.

There is, however, indication that two individual dinosaurs walked together at one point.  The size and shape of the footprints suggest those dinosaurs were theropods, possibly Deinonychus.

Figure 2. Map of dinosaur localities in the vicinity of Agadez, Rep. Niger. Generated with GoogleEarth MapMaker Utility 2009. https://doi.org/10.1371/journal.pone.0014642.g002

Taking casts of the perfectly preserved Paravipus didactyloides trackways. About 1 mile SE of the Spinophorosaurus site, Aderbissinat. These tracks were later scientifically described in PlosOne by our team. They were caused by rather large dromaeosaurids (“raptors”). The tracks are numerous, large, perfectly preserved, the first proof for this group from rocks as old als middle Jurassic and, last but not least, the first proof for this group in subsaharan Africa. The person with hat is Michel Rabe, volunteer at our museum. The three guys to the right are Tuareg and Hausa helpers. Photo and caption courtesy of Dr. Ralf Kosma

Photo courtesy of Dr. Ralf Kosma

After removing the silicone mould of the Paravipus tracks. Michel Rabe (with hat) and me (with turban). Photo and caption courtesy of Dr. Ralf Kosma

 

In 2009, the State Museum of Natural History in Braunschweig opened “Projekt Dino,” an exhibition highlighting dinosaurs from West Africa.

“It was open to public for 4 months until March 2010, as far as I remember,” wrote Dr. Kosma. “Afterwards Spinophorosaurus [nigerensis—another sauropod from Niger] and Jobaria [tiguidensis] were moved to our main building.  Since 2010, the Niger-story is represented in our permanent exhibition…[W]e dedicated a complete hall–our dinosaur hall–to that topic.  Visitors of all ages are very fascinated by these skeletons. They are a central point of interest and strongly help the understanding of Earth history…Many school classes come here to learn about the giants of the Mesozoic.”

Photo courtesy of Dr. Ralf Kosma

The acknowledgments at the end of “Subchondral cysts at synovial vertebral joints as analogies of Schmorl’s nodes in a sauropod dinosaur from Niger” state: “We also thank the people of Aderbissinat, Niger, for all the support and help they have offered us during our field campaigns.”

At the beginning of “Didactyl Tracks of Paravian Theropods (Maniraptora) from the ?Middle Jurassic of Africa,” it is noted that in exchange for paleontological work and recovery of fossils, part of the funds donated for the research were given toward building a local school, providing food for the children and 20,000 school books.

In corresponding with Dr. Kosma, one of his comments struck a personal chord with me:

“We all miss Niger very much: the country, the people, the desert, and would like to go there again digging for dinosaurs. We are still in contact with the local people, and they tell us the situation of the civil war is getting better right now.”

 

 

References:

1. Florian Witzmann, Oliver Hampe, Bruce M. Rothschild, Ulrich Joger, Ralf Kosma, Daniela Schwarz & Patrick Asbach (2016) Subchondral cysts at synovial vertebral joints as analogies of Schmorl’s nodes in a sauropod dinosaur from Niger, Journal of Vertebrate Paleontology, 36:2, DOI: 10.1080/02724634.2016.1080719
2. Mudroch A, Richter U, Joger U, Kosma R, Idé O, Maga A (2011) Didactyl Tracks of Paravian Theropods (Maniraptora) from the ?Middle Jurassic of Africa. PLoS ONE 6(2): e14642. https://doi.org/10.1371/journal.pone.0014642
3. Salisbury, S, and E. Frey.  2001. A biomechanical transformation model for the evolution of semi-spheroidal articulations between adjoining vertebral bodies in crocodilians; pp. 85 – 134 in G. C. Grigg, F. Seebacher, and C. E. Franklin (eds.), Crocodilian Biology and Evolution. Surrey Beatty and Sons, Chipping Norton, England.

 

An absolutely tremendous and heartfelt thank you to Dr. Ralf Kosma, who was not only very generous with the pictures he provided of his experiences, but with his help and patience with this blog.  It took much longer to write this post than normal; he was exceedingly kind throughout the process.

An equally heartfelt thank you to Dr. Florian Witzmann, who not only put me in touch with Dr. Kosma, but helped clarify some points on his research.

A special thank you to Dr. Emanuel Tschopp who kindly confirmed the species of sauropod to be Jobaria tiguidensis (so far!)

Sousatitan: Brazil’s oldest sauropod bone found in a sea of trace fossils

One man happened to see the bone; one scientist happened to see the picture he posted online.

These two chance occurrences brought about a remarkable discovery: the first fossil dinosaur bone to be found where none have been found before.

Not only is it the first dinosaur bone in the area, it is also the oldest sauropod bone in Brazil to-date, a new as-yet-unnamed species of titanosaur.

Luiz Carlos Gomes was looking for fossil footprints in Sousa, Brazil. Hundreds upon hundreds of trackways, footprints and other trace fossils have already been found in Paraíba–a state in the West coast of that country and where Sousa is located–in an area known as the ‘Valley of the Dinosaurs‘ (‘Vale dos Dinossauros‘). But actual bone fossils? None.

None, that is, until he recognized actual bone within rock.

“He was the main [person] responsible for the discovery,” wrote Dr. Aline Ghilardi, paleontologist at Universidade Federal de São Carlos, in an email. “Luiz Carlos is a very curious retired gentleman whose hobby is to look for dinosaur footprints. He found the bone by chance (it was still inserted into the rock, so he knew it was not only a recent bone), took a picture of it and posted on the internet. Searching information about the area, I found the photo by chance, and, knowing the importance of the discovery, immediately got in touch with him.”

 

Images of fossil footprints found in the Valley of the Dinosaurs (Vale dos Dinossauros) in the state of Paraíba, Brazil; screenshots from the Colectionadores de Ossos (Bone Collectors) video; courtesy of Aline Ghilardi and Tito Aureliano.

 

Image of Luiz Carlos S. Gomes and Dr. Aline Ghilardi; screenshot from the Colectionadores de Ossos (Bone Collectors) video; courtesy of Aline Ghilardi and Tito Aureliano.

 

That bone was the subject of a paper published this past July in Cretaceous Research by Aline Ghilardi, Tito Aureliano, Rudah Duque, Marcelo Fernandes and Anusuya Chinsamy-Turan (“A new titanosaur in the Lower Cretaceous of Brazil“).

 

Fossil of the sauropod bone found in-situ in Sousa, Brazil, nicknamed ‘Sousatitan’; courtesy of Aline Ghilardi.

 

Through its bone histology, they believe this fibula belonged to a young titanosaur, rather than a small adult.  They noted rapid growth, and they highlighted an aspect within the bone that intrigued them.  In their paper, they point out that “…the lateral part of the bone wall has what appears to be bone tissue not formed in laminae and a predominance of longitudinally orientated vascular channels within a woven bone matrix.”

“This suggests that different parts of the bone wall [are] growing at different rates,” wrote Dr. Anusuya Chinsamy-Turan, paleobiologist and professor at the University of Cape Town, “i.e.: the rate of bone formation is not constant around the whole cross section of the bone wall.”

Image of “fibrolamellar bone tissue in the process of being deposited on the medial side of the bone wall” and Anusuya Chinsamy-Turan; screenshot from the Colectionadores de Ossos (Bone Collectors) video; courtesy of Aline Ghilardi and Tito Aureliano.

Their comparisons with other titanosaur fibula indicate it is a new species, although the authors are cautious about this.  And using a complicated mathematical formula, they can estimate the size of Sousatitan, the nickname they have given this dinosaur.

Tito Aureliano, a PhD student at the Universidade Federal de Pernambuco, helped elucidate how, equipped with a single fossil bone, they could make an educated guess about its size. His solution involved tweaking a previously published equation and quite a bit of ichnofossil measurement.  Keep in mind that the Valley of the Dinosaurs has at least 74 known sauropod footsteps.

Tito Aureliano; screenshot from the Colectionadores de Ossos (Bone Collectors) video; courtesy of Aline Ghilardi and Tito Aureliano.

 

“We used equations in two steps in our paper,” he explained by email, “because we needed to relate and compare one single fossil specimen to the abundant ichnospecimens from Sousa. The most accurate and mathematically secure way to do that (and [to avoid] speculation) was calculating hip height joint from footprints and total leg height from the bone we found.  We didn’t work with total length because that varies quite a lot in Titanosauria, and it wouldn’t be [scientifically useful].”

“First, we observed titanosaur tracksites from the same age as Sousatitan’s leg size.  We measured the diameter of every ‘back leg’ footprint available at Rio Piranha Formation outcrops.  Then, we calculated the hip height of all titanos that roamed the area at this formation and noticed there were a variety of sizes in individuals.

 

 

Fig. 4.; image from A new titanosaur from the Lower Cretaceous of Brazil, Cretaceous Research.

“Previous authors developed equations to predict general dinosaur hip heights from tracksites, but if you are working specifically with titanosaur ones, you should work with the Argentinian equation.  González-Riga found a complete articulated titano leg in the same area he has encountered large footprints that fit exactly in size with his fossil.  By using this evidence, he was able to develop this accurate equation to estimate hip height from a single titanosaurian footprint.

“Secondly, we had to estimate Sousatitan’s leg size. We had just one single bone. How did we do that?  In González-Riga’s paper I mentioned before, he also presented a formula to calculate total leg length from its skeletal elements.  The major problem is that it had so many variables and geometry elements in it.  It would be impossible [to use] if a scientist has only one or two of these elements.  So, I worked on the equation to simplify it into just three variables: femur, ulna and fibula length. H = ¼1.106*(0.96F + T), where H represents hip joint height, F is femur length, and T is tibia length.  Now colleagues with less titanosaur limb bones [can use] González-Riga’s original idea with what they have.”

 

A view of Sousatitan’s fibula (or ‘DGEO-CTG-UPFE-7517’), viewed from every angle; screenshot from the Colectionadores de Ossos (Bone Collectors) video; courtesy of Aline Ghilardi and Tito Aureliano.

 

 

Great depiction of the estimated size of Sousatitan (in black) with the fossil found; image from A new titanosaur from the Lower Cretaceous of Brazil, Cretaceous Research.

 

Tito continued, “‘Ok, a cool new formula with three elements. But you have just one! How did you do it then?’

“It’s simple morphometry.  I gathered limb bones from a lot of different titanosaur genera and measured the ration between these three bones. Then, I could estimate the theoretical size of the other limb bones.”

Sousa Basin stratigraphy; image from A new titanosaur from the Lower Cretaceous of Brazil, Cretaceous Research.

 

Coming from an area of the United States known more for ichnofossils than bone fossils, I share their excitement.

And yet, “internationally, for now, we have only observed colleagues’ mentions regarding the work and its importance,” wrote Dr. Ghilardi.

Fortunately, this sense of excitement seems to permeate Brazil.

“The discovery is getting lots of attention in Brazil, from both our colleagues and the popular media,” she continued. “The bone’s discovery was announced in all major newspapers of the country and, [thus far], in two of the largest television channels of Brazil.  Visits to the ‘Vale dos Dinossauros’ Park (where the bone is now housed) increased significantly after the first announcement of the discovery in popular media.  The dinosaur’s nickname got very popular and soon reached even Wikipedia in Portuguese.”

Dr. Aline Ghilardi; screenshot from the Colectionadores de Ossos (Bone Collectors) video; courtesy of Aline Ghilardi and Tito Aureliano.

 

When I asked what brought these six scientists–from Brazil and South Africa–together on this research, Tito Aureliano explained that he and Dr. Ghilardi are married.  In addition, he explained, “our friend, [Rudah] Duque, is a technician in paleontological preparation at PaleoLab (UFPE, Recife city). Prof. Barreto is the chief of the PaleoLab. We have been working together for the past four years visiting the least explored areas of NE Brazil in search of new Cretaceous fossils.

“Prof. Anusuya had previously assisted us in pterosaur research [that included] some histological observations. She possesses not only great knowledge on the subject, but she is also very polite and friendly. Aline and I think it was wonderful to work with her and to learn from her.

“Our friend Marcelo is the chief of the Paleontological Museum of the Universidade Federal de São Carlos. He is a renowned specialist in dinosaur ichnofossils (he is that guy that published the first urolite, ‘dinosaur pee‘).”

Dr. Marcelo Fernandes; screenshot from the Colectionadores de Ossos (Bone Collectors) video;  courtesy of Aline Ghilardi and Tito Aureliano.

 

Trace fossils from paper by Fernandes et al corresponding to liquid wastes (urolites!); screenshot from the Colectionadores de Ossos (Bone Collectors) video;  courtesy of Aline Ghilardi and Tito Aureliano.

 

Without doubt, the authors will continue to search for additional bone fossils in the area.

“The intention is to seek funding to continue doing searches in the region.  We hope to find more material in [the] Lagoa do Forno site (including other parts of the same individual) and also other promising localities,” Dr. Ghilardi wrote.

 

 

Location of the find and map of Brazil; image from A new titanosaur from the Lower Cretaceous of Brazil, Cretaceous Research.

 

“I believe it is worth mentioning the importance of the contact between researchers and the population,” she added.  “It is always a good partnership and yields good results.  The locals are interacting every day with the fossiliferous rocks, therefore, they are the most likely people to find materials such as this bone.

“[Making] people feel part of the scientific knowledge process is a very effective way to preserve paleontological heritage for future generations. And not only create a sense of protection about it….but also a sense of pride in their heritage and their land.  Finally, this can be a fundamental social change factor for the local population, which is so needed in so many respects.”

Referencing Sousatitan’s discoverer, Luiz Carlos Gomes, she wrote, “Today, he is very proud of [what has transpired since the initial find].”

 

Depiction of Sousatitan amongst larger sauropods of the same species; artwork by Marcos Paulo; courtesy of Aline Ghilardi and Tito Aureliano.

You can help the Bone Collectors continue to educate the public by donating here! 

 

It was a remarkable honor and pleasure connecting with Dr. Aline Ghilardi, Tito Aureliano and Dr. Anusuya Chinsamy-Turan. That cannot be stated enough! It was exciting to learn more about their incredible discovery, and they were very generous with their time and help. From New England to Brazil and South Africa: THANK YOU!!

 

References:

1. A new titanosaur from the Lower Cretaceous of Brazil, Aline M. Ghilardi, Tito Aureliano, Rudah R. C. Duque, Marcelo A. Fernandes, Alcina M. F. Barreto, Anusuya Chinsamy; Cretaceous Research, Vol 67, December 2016; http://dx.doi.org/10.1016/j.cretres.2016.07.001

Videos by the Bone Collectors (Colecionadores de Ossos), several authors of this research:

Further Information:

1. Bone Collectors – Colecionadores de Ossos: http://bonecollectors.org (website of several of the authors in this paper)
2. The Bone Collectors’ Blog: http://scienceblogs.com.br/colecionadores
3. Bone Collectors – Colecionadores de Ossos on YouTube: https://www.youtube.com/user/ColecionadoresOssos
4. Um novo dinossauro Brasileiro: blog post about the Sousatitan discovery by Aline Ghilardi on the Bone Collector blog
5. Occurrence of urolites related to dinosaurs in the Lower Cretaceous of the Botucatu Formation, Paraná Basin, São Paulo State, Brazil, Marcelo A. Fernandes, Luciana B. R. Fernandes, Paulo R. F. Souto, Revisita Brasileira de Paleontologia, July/August 2004
6. Dinosaurs Without Bones, Anthony J. Martin, 2014, Pegasus Books — (Dr. Martin includes an illustration of one of the urolites discovered by Fernandes et al in this book; he also discusses their research on pages 245-246!)

 

 

Fossilized Footprints – Dr. Karen Chin on the work of Dr. Martin Lockley

There is something uniquely spectacular about trace fossils.

Trace fossils—or ichnofossils—are fossilized remnants of animal activity. They are echoes of animal life, many that are millions of years old, that we can see and touch, tantalizing clues into their behavior and environment.

These traces take a number of forms, including coprolites (feces), gastroliths (stones ingested to help digestion), burrows, nests, and footprints.

 

Embed from Getty Images

 

[image of dinosaur tracks, Colorado, courtesy of David Parsons and Getty Images]

Footprints are the focus of Dr. Martin Lockley’s work.  Over 30 years of his fossilized track research now resides at the University of Colorado Boulder.

Dr. Karen Chin, another trace fossil specialist with decades of experience, is widely known for her work on coprolites.

 

 

[images of coprolite and display info from the Boston Museum of Science, taken by the author]

The work of these two scientists comes together in the exhibit “Steps in Stone,” now at the University of Colorado Museum of Natural History.  Showcasing some of Dr. Lockley’s extensive collection, the exhibit is curated by Dr. Chin.

[image of exhibit entrance, courtesy of the CU Museum of Natural History]

Originally from the UK, Dr. Martin Lockley began teaching at the University of Colorado Denver in the 1980’s.  He retired in 2010, but his research continues today.

“When he decided to retire from his professor position,” Dr. Chin explained in a phone interview, “he wanted his research collection to go to a place where it would be cared for in perpetuity and would still be available for people to study.  And since the University of Colorado Boulder is a sister institution to the University of Colorado Denver, it made sense for the collection to come to us.”

An accompanying website, with text written by Allison Vitkus—one of Dr. Chin’s graduate students—Dr. Karen Chin and Dr. Martin Lockley, describes in more detail the type of tracks Dr. Lockley has collected and donated to the University.

“Because of Prof. Lockley’s efforts, the University of Colorado’s Fossil Tracks Collection is exceptional in having specimens that represent tremendous temporal, taxonomic, and geographic breadth. It includes around 3,000 original or replica specimens of footprints and trackways, as well as about 1,600 full-size acetate footprint and trackway tracings. These specimens come from over 20 countries on five continents (including 21 states within the USA).” – Allison Vitkus, Dr. Karen Chin

http://www.ucmp.berkeley.edu/science/trackways/index.php

Moving such a collection from one university to another is not a small enterprise.

“Martin Lockley and I applied for and received an NSF (National Science Foundation) grant to help us transfer the tracks to our museum.”

Dr. Chin described the process of creating the current exhibit, a team effort of about 15 people from various departments within the Museum of Natural History.

“Allison and I had already been writing about different aspects of fossil track research.  We sat down and asked, ‘what are the things that we think are the most fundamental and interesting concepts of fossil tracks that would be interesting for people to learn about?’  We then put together a list of things we wanted to write about and matched that with tracks in the collection.”

 

[image of Dr. Karen Chin and exhibit docents, courtesy of the CU Museum of Natural History]

“We decided we wanted people to think about the concept of ‘moving’ and to recognize that fossil tracks tell us about locomotion in the past. ”

In other words, it is not just a look backward in time; it encourages the visitor to think about movement in all forms today and the evolution of that movement over Earth’s history.

Embed from Getty Images

Consider, for example, how fish might make tracks: fins brush the ground while swimming in shallow water.  Consider, too, the tracks animals make while running, walking, limping, or even swimming.   The type of footprint remaining and the length between each step (or stroke) offers valuable insight to scientists. Insects, mammals, birds, pterosaurs, dinosaurs….all of these species have left their marks in stone, and all of them are represented in this exhibit.

To help highlight how different body structures affect the type of tracks an animal leaves, members of the museum’s educational department procured imitation animal tails that kids can wear.  Kids are also encouraged to ‘Walk Like a Pterosaur!’ in which they can don representations of pterosaur forelimbs with wings.

“There’s a portion of the exhibit that’s called ‘Locomotion Without Legs,’ that reminds us that not all animals that leave tracks or traces have legs,” said Dr. Chin. “Modern snails and sea urchins and are good examples of this.”

“We discuss the oldest evidence that we know of for movement in the fossil record, which is about 565 million years. We don’t know what kind of animal made the trace. It may have been something like a sea urchin, but we just don’t know.”

“There are a certain number of deposits around the world that preserve weird impressions of animals from before the Cambrian,” she continued. “Actually, we don’t even know whether all of them were animals or plants! There are no modern analogues of these organisms because they went extinct.”

“One of the oldest deposits of this particular biota comes from Newfoundland.  Researchers found an unusual trace in this deposits that extends for several inches.  The trace appears to provide evidence of locomotion.  This suggests that an animal had the capacity to move itself, which further suggests that it had muscles.  This is a huge deal because the fossil trace is so old. I think this is very cool because we often take our ability to move for granted.”

This particular trace fossil was described by Dr. Alexander Liu, Dr. Duncan McIlroy, and Dr. Martin Brasier in 2010.  How fascinating to think that something this small and from an organism that remains a mystery provides important evidence for movement when the Earth was still relatively young. (First evidence for locomotion in the Ediacaran biota from the 565 Ma Mistaken Point Formation, Newfoundland) The actual trace fossil is not part of the exhibit, but its image is available for visitors to see.

“We often automatically think that animals have the ability to move from point A to point B,” Dr. Chin mused. “But there are a number of very successful animals that live without relocating from one place to another, such as sponges and corals.   So it is interesting to think about when animals first developed the ability to move. ”

Another example of the variety and importance of tracks are the Laetoli trackway: a set of prints from Tanzania.  The exhibit displays a life-sized cast of the trackway, footprints from two hominin adults and a smaller set of footprints that might have been a child.

“Their footprints were preserved when they walked on recently deposited volcanic ash. These tracks are important because they provide some of the earliest evidence that our ancient relatives, the australopithecines, walked bipedally.”

“As Dr. Lockley has continued his research on tracks,” explained Dr. Chin, “he has often acquired replicas of fossil tracks from around the world.  That is what is great about tracks: that you can make a lot of different casts of them.”

“It’s an intense process,” Dr. Chin stated, referring to the creation of an exhibit. “There are so many details. But I gained new appreciation for the great work that the exhibit designers and the museum education people do.”

In response to whether it was a positive experience, she said, “I did enjoy it!”

“Now, I have to say,” she laughed, “it’s a lot of work.  I didn’t mind the work, it’s just that I’m also teaching and doing research, so it’s kind of hard to juggle doing all of that at the same time.”

“I think there are two larger points that I’d like people to take away from the exhibit.

“I want people to gain a sense of appreciation for the tremendous amount of research Dr. Lockley has done on fossil tracks all over the world.

“I also want people to appreciate the informative value of tracks and other trace fossils.”

[image of Dr. Karen Chin and docents, courtesy of the CU Museum of Natural History]

“At many times we tend to focus on body fossils: the bones of mammoths and the bones of dinosaurs, for example. They are very interesting, and they really fire up our imagination in considering what those ancient animals were like.

“But, I also want people to appreciate that trace fossils–which provide evidence organisms’ activity—also offer important information on the history of life.

“It’s very much akin to walking on a trail these days and looking for animal sign.  You look for tracks and scat and scratches and toothmarks.  And we do the same when we look for trace fossils in the fossil record.  Tracks are just one exciting example of trace fossils.”

 

Embed from Getty Images

——————–

A Mammuthus columbi-sized THANK YOU to Dr. Karen Chin for her time, her fascinating insight and for generously helping me understand Ediacaran biota!  It was a tremendous honor and pleasure for me to connect with her.  An enormous thank you to Cathy Regan as well for providing wonderful images of the exhibit!

“Steps in Stone” is available through December 31, 2015: http://cumuseum.colorado.edu

If you are interested in learning more about trace fossils, Dr. Martin Lockley has written a number of books.  Dinosaurs Without Bones by Dr. Anthony J. Martin was published this year, and this author highly recommends it!