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!)

North American Proboscideans and Dr. Chris Widga – Part 1

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

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

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

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

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

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

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

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

But it’s not an easy task.

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

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

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

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

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

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

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

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

 

 

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

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

 

 

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

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

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

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

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

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

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

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

 

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

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

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

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

*****

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

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

References:

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

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