The fascinating stories of 7 Brazilian dinosaurs – 02/16/2023 – Science

It was after an exhibition organized in 2006 at Oca, in Ibirapuera Park, in São Paulo, that paleontologist Luiz Eduardo Anelli identified a nuisance.

“Wow, why has Argentina already described 150 species of dinosaurs and Brazil only has 23?”, he asked at the time.

With this questioning, the idea of ​​writing a book about the great reptiles of the past that lived where we identify the Brazilian territory today was born.

However, after a few years of the first edition of the text, the work was already obsolete.

“Over the last 15 years, the number of dinosaurs identified in Brazil has multiplied and I needed to update”, says the researcher, who is also director of the Science Station at the University of São Paulo (USP).

Thus, the book “Novo Completo Dinossauros do Brasil” was published, recently released by Editora da USP (Edusp) and Editora Peirópolis.

The work brings details about 54 cataloged species of “Brazilian” dinos and explains all the evidence about the emergence of the planet and life over millions of years. The illustrations that accompany the text were made by paleoartist Julio Lacerda.

It is worth remembering, as the scale below shows, that dinosaurs were the dominant beings during the Mesozoic era, which comprises a period from 252 million to 65.5 million years ago.

In an interview with BBC News Brasil, Anelli highlighted seven species described in Brazil with interesting and curious characteristics, as you can see throughout the article.

geological time scale

1 – Staurikosaurus, the elder

There is a reason for Staurikosaurus pricei to be the star of the book cover: it is considered the oldest dinosaur ever found in the world.

The dating of nearby rocks reveals that this animal lived 233 million years ago. With that, he is about 1.8 million years older than some other dinosaurs discovered in Argentina, such as the Eoraptor and the herrerasaurus.

“In what we now know as Rio Grande do Sul, possibly the first lineages of dinosaurs were born that would colonize and dominate the world over the next 170 million years”, estimates Anelli.

Currently, the only known fossil from the staurikosaurus is at the Museum of Comparative Anatomy at Harvard University, in the United States.

2. Buriolestes, the forerunner

Anelli highlighted the buriolestes schultzi because of an apparent contradiction.

“The scientific community was somewhat shocked to learn that Buriolestes was a carnivorous/faunivorous biped that gave rise to later lineages of herbivorous quadrupedal dinosaurs,” he summarizes.

Specialists were lucky enough to find two practically complete skeletons of this species. They had their skull preserved, including the masses of what were the brains of these animals in the past.

“With that, it was possible to obtain tomography images to learn about all the shapes, protuberances and characteristics of the brain of this species”, he says.

“This is how we discovered the ‘great-grandfather’ of long-necked dinosaurs, so this is a heritage of biology and natural history”, says the paleontologist.

3. Ubirajara, the controversial

Listed in 2020, the Ubirajara jubatus it is also considered a rare piece.

“It is the first non-flying dinosaur found in the Crato region, in Ceará, and it has down, or feathers”, describes Anelli.

“In addition, the Ubirajara it had two pairs of long feathers on its back, very similar to those seen today on birds of paradise [típicas da Oceania]”, he adds.

According to the scientist, one possibility is that these structures served to vibrate and shake during mating rites — a characteristic that, it should be said, some birds maintain until the present day.

And this is not the only behavior that brings birds and dinosaurs together: both sleep (or used to sleep) with their necks wrapped around their bodies, build (or used to build) nests and lay (or laid) eggs with similar characteristics.

Unfortunately, the Ubirajara is involved in a controversy. “It was taken to Germany in a suspicious manner and the researchers, as well as the museum that now houses it, refuse to return it”, informs the book.

“But there are rumors that the Ubirajara is coming home soon,” he adds.

4. Oxalaia, the fisherman

This giant was characterized from two fragments: the upper end of the snout and a piece of the left maxilla.

This is because the rocks where these fossils were located, on an island in the state of Maranhão, suffer from the effects of waves and tides — hence much of the material has degraded.

Anelli draws attention to the fact that, at the time the Oxalaia quilombensis existed, South America and Africa had just separated (before, they were part of a supercontinent known as Gondwana).

Therefore, there are many similarities between this Brazilian dino and some others that were discovered on the African coast.

“Apparently, the Oxalaia it was a fisherman dinosaur”, adds the anthropologist.

The scientific name of the species makes a reference to the Afro-Brazilian deity Oxalá and the Quilombola settlements in Maranhão.

5. Ibirania, the runt

85 million years ago, the region we know today as the interior of São Paulo was not one of the easiest places to live.

Resources such as water and food were scarce — and the few animals that ventured into these lands had to adapt.

An example of this process is the Silly Ibiraniaa runt-necked dinosaur.

“It most likely reflects a time in the Cretaceous, which had a very dry climate, with little availability of food”, assesses Anelli.

By an evolutionary strategy in a time of lean cows, the Ibirania it was tiny, even more so when compared to other dinosaurs that appeared in later times.

6. Berthasaura, the Toothless

The name Berthasaura leopoldinae pays a triple tribute.

First, to Brazilian scientist and activist Bertha Lutz. Second, to Empress Leopoldina, wife of D. Pedro 1st. Third, to the Rio de Janeiro samba school Imperatriz Leopoldinense, which paid homage to the National Museum at the 2018 carnival.

Anelli describes the berthasaura in the book as a “precious gem”.

“She was a hunting dinosaur, but without teeth”, he summarizes.

“We still have a lot to discover about this species, which had very different living and hunting habits from traditional dinosaurs, full of hard teeth”, he adds.

It is likely that the mouth of the berthasaura was coated with a “horny beak with sharp edges similar to that of turtles”.

7. Uberabatitan, the colossus

Here is the largest dinosaur ever found in Brazilian territory.

“O uberabatitan ribeiroi it was enormous, reaching 26 meters in length”, estimates Anelli.

“That’s about the size of two big buses in a row.”

It is one of the most complete titanosaurs known from all over Brazil and surpassed by one meter the Austroposeidon magnificuswhich was previously considered the largest in the country.

Regions where the seven dinosaurs were found

Argentina in the lead

As mentioned at the beginning of the report, Anelli was intrigued by the disparity in the number of dinosaur species described in Brazil and Argentina.

The paleontologist highlights three main reasons for this difference.

“The first is that during the Mesozoic [a era dos dinossauros]the territory of present-day Argentina has always been glued to the ocean, with access to moisture and basic resources for survival”, he contextualizes.

“Brazil, in turn, was located in the inner part of the supercontinent Gondwana. Normally, these central regions are taken over by deserts, with a water deficit and little biodiversity”, he adds.

Second point: with the passage of millions of years and the separation of South America and Africa, the situation was reversed. The Brazilian territory began to receive all the humidity that came from the brand new Atlantic Ocean and became a kind of supertropical oasis.

On the other hand, the rise of the Andes Mountains blocked the entry of moisture into Argentina from the ocean. As a result, the region turned into a desert.

And this exchange of roles also facilitated the preservation of fossils on the Argentine side. “If you travel through Patagonia, you can see several exposed rocks. The desert preserves this material”, explains Anelli.

“Now, when taking a car and crossing the interior of São Paulo, it is possible to come across kilometers of cane fields and scrubland. This is because the layer of soil with organic material is very thick, which makes it difficult to preserve and discover fossils. “

“To top it all off, interest in paleontology began much earlier among Argentines. We have dinosaurs described there since the end of the 19th century”, says the researcher.

In Brazil, in turn, this area of ​​science began to gain momentum from the 1970s onwards, and many of the species described in Anelli’s new book were only discovered in the last decade.

Few representatives of the Jurassic

Another aspect that raises the curiosity of scientists is the low number of “Brazilian” representatives in the Jurassic Period (which goes from 201 million to 145 million years ago).

“The Jurassic is a period of more than 50 million years in which dinosaurs exploded in diversity all over the world. And in our country, we only know of two or three species”, says Anelli.

The first of these is a nodosaurid, whose footprints were found in Rio Grande do Sul.

The other two, which are still the subject of debate among paleontologists and have very scanty evidence, are Carcharodontosaurus and a dilophosaurid, detected on the border between Pernambuco and Bahia.

Geological changes are once again behind this “disappearance”.

“The fossils are only ‘registered’ in the rocks when the regions of the continents are sinking. This makes room for the accumulation of sediments over the land”, explains the paleontologist.

“But these geological movements also happen in the opposite way: rocks can emerge. When this happens, the oldest layers are exposed to the weather, rain, heat, cold and erosion. With that, the fossil record is erased. “

And that was exactly what was happening in the “Brazilian” Jurassic: the rocks were moving upwards.

“That is, dinosaurs lived in Brazil during this period, but geology did not ‘write’ this history in the rocks”, he adds.

At a later time, during the Cretaceous (from 145 to 65.5 million years ago), the platform of the Brazilian territory began to give way — due to the separation of the supercontinent Gondwana and a series of other phenomena.

With that, the sediments accumulated, were “registered” in the rocks and can be found by human beings in more recent years.

a missed opportunity

Finally, Anelli regrets the little attention given to Brazilian dinosaurs.

“We should have dolls of all these species for sale”, he believes.

“Dinosaurs are one of the subjects of science that most attracts people’s attention. We managed to set up exhibitions and take hundreds of thousands to museums and public spaces”, he reports.

Anelli remembers that every big city in North America and Europe has “a big museum full of dinosaurs”.

The researcher, who has plans to create the “Dinosaur Route in the State of São Paulo”, understands that it is possible to explore and popularize all this paleontological knowledge for the population.

“We need to learn to take advantage of our prehistory, which is fascinating. We have super cool discoveries, but we don’t teach any of this in schools”, he concludes.