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.”

 

Trackway from Bone Collectors Video - Brazil

More tracks in Brazil from Bone Collectors video

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.

 

Luiz Carlos and Aline from Colecionadores de Ossos video

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“).

 

DSC_0025 - Sousa fossil in-situ

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.”

Research from Anusuya Chinsamy from Colecionadores de Ossos video

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 from Colecionadores de Ossos video

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.

Comparative image of titantosaur fibula

 

 

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.”

 

Sousatitan fossil from Colecionadores de Ossos video

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.

 

Size comparison Sousatitan

 

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

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.”

Aline Ghildardi from Colecionadores de Ossos video

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‘).”

Marcelo Fernandes from Colecionadores de Ossos video

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

 

Urolites from Fernandes et al paper from Colecionadores de Ossos video

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.

 

Sousatitan map of discovery

 

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].”

 

Sousatitan by Marcos Paulo

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!)

 

Pegasus - Dinosaurs Without Bones, Anthony Martin