Dinosaur: road work in MG reveals fossil eggs – 05/22/2023 – Science

A work at a junction of two highways, between the states of Minas Gerais and Goiás, revealed fossil eggs of a possible carnivorous dinosaur or crocodyliform.

The fossilized eggs were found by Paulo Macedo, a paleontologist from the Geopac Geology and Paleontology Consultancy company, who worked at the site, known as “Trevão”, close to the municipality of Monte Alegre de Minas.

The Ecovias Cerrado concessionaire, responsible for the BR 365 and BR 153 roads, helped with the removal of the material, which is now in the paleontology laboratory of the State University of Minas Gerais, in the municipality of Ituiutaba.

The finding was disclosed this Monday morning (22) at the State University of Minas Gerais, Ituiutaba campus. The delivery of the eggs to the University’s Paleontology Laboratory will now allow future analyzes and studies on this and other fossil finds in the region.

In all, five eggs were found. The estimated age is approximately 80 million years (Late Cretaceous). Fossil eggs have characteristics that resemble an elongated bird’s egg, with a smooth shell (no grooves) and an approximate size of 6 cm.

Among the fossil material, there are two fragmented eggs, one partially broken and two intact, which can reveal whether there are fossilized remains of an embryo inside. The shell thickness is approximately 1 millimeter, also similar to the pattern seen in carnivorous dinosaur eggs.

According to Luiz Carlos Ribeiro, geologist and researcher at the Scientific and Cultural Complex of Peirópolis, at the Federal University of Triângulo Mineiro, it is not possible to know if the fragmented eggs hatched or if they suffered breakage due to burial. “In any case, the finding is unexpected and represents an important discovery, with implications for the ecology of an environment that was very different from today 80 million years ago.”

As the observed pattern is found both in eggs of carnivorous dinosaurs (a lineage that includes birds and theropods) and in crocodyliforms (a group that includes current crocodilians, such as alligators, crocodiles and gharials and the already extinct forms), more detailed analyzes in laboratory will be able to determine which group the litter belonged to.

“The porosity and microstructure of the eggshell will determine whether it is theropod or crocodyliform, because the eggs of carnivorous dinosaurs are very similar to birds”, explains paleontologist and professor at USP’s Institute of Geosciences Luiz Anelli.

Fossil eggs are rare in Brazil. Some of the most recent discoveries were found in the interior of São Paulo, close to the municipality of Presidente Prudente, and in Minas Gerais, close to the municipalities of Uberaba (where titanosaur eggs were found) and Uberlândia, in the Triângulo Mineiro region.

This entire area is part of the so-called Bauru Basin, a large sedimentary basin located between the states of São Paulo, Minas Gerais, Mato Grosso and Mato Grosso do Sul.

According to Macedo, there is also a record of a nest in Uberaba, which may or may not belong to the same group that laid eggs in the region of Monte Alegre de Minas. “Despite being part of the same basin, the Vale do Rio do Peixe formation, where the brood comes from, is not the same as that found near Uberaba, the sediment is softer, composed of sandstone, and we have no record of dinosaurs yet to the region.”

One of the main difficulties when analyzing fossilized eggs is that often all the rest of the animal (ie the skeleton) has already been replaced by sediments from the rock itself, making it difficult to separate the organism from the mineral. The exception was an egg with an embryo “about to be born” found in China in December 2021.

Research on the organism that deposited that egg, as well as on the importance of the site for ecological and paleontological knowledge, should continue in the coming months.

“Since dinosaur eggs are still little known in Brazil, compared to other countries with rocks of similar age, finding nesting areas or obtaining information about the ecology of these animals is fundamental”, completes Anelli.

In the same region, some of the most important Brazilian dinosaurs have already been excavated, such as the uberabatitan ribeiroithe largest long-necked dinosaur known in Brazil, with an estimated size of up to 15 meters in length.

According to Daniela Almeida, sustainability coordinator at Ecovias Cerrado, the discovery is of great importance to the scientific community due to its age and the potential it represents for paleontology studies in the region. “We form partnerships with companies and universities for the development of research in areas close to the works, ensuring the preservation of historical heritage.”