Paleontologists discover fossils of new species of crocodile-like reptile that lived 237 million years ago

Paleontologists have discovered a new species of ancient crocodile-like reptile that once roamed the lands and waters of Brazil.

The fossils, found at a fossiliferous locality called “Linha Várzea 2” in southern Brazil, have now been named Parvosuchus aurelioi, an ancient new species of small predatory reptile dating back to approximately 237 million years ago, according to a published study in Scientific Reports. on Thursday.

PHOTO: Paleontologist Rodrigo Müller holds the fossils of Parvosuchus aurelioi, an ancient crocodile-like reptile found in Brazil.

Paleontologist Rodrigo Müller holds the fossils of Parvosuchus aurelioi, an ancient crocodile-like reptile found in Brazil.

Janaina Brand Dillmann

The new species belongs to a group of crocodile-like reptiles called pseudosuchians and is the first “ambiguous” gracilissuchids, an extinct genus of small pseudosuchians, said Rodrigo Müller, a paleontologist at the Universidade Federal de Santa Maria and lead author of the work. ABC News by email.

Before dinosaurs dominated the land, pseudosuchians were a common form of reptile during the Triassic period.

The fossils were discovered in fossiliferous beds that predate those harboring the oldest dinosaurs, giving scientists clues about “ecosystems that existed before the dawn of the dinosaur age,” Müller said.

“The presence of this small predator among the fossils of much larger predators suggests that these ecosystems, where Brazil is today, were more complex than previously imagined,” he said.

PHOTO: Middle-Late Triassic landscape of southern Brazil depicting a large Prestosuchus chiniquensis feeding on the carcass of a dicynodont while individuals of Parvosuchus aurelioi compete for the remains.

Middle-Late Triassic landscape of southern Brazil depicting a large Prestosuchus chiniquensis feeding on the carcass of a dicynodont while individuals of Parvosuchus aurelioi compete for scraps.

Matheus Fernandes

Gracilisuchids are extremely rare, Müller said, adding that there are only three other species worldwide: two from China and one from Argentina.

According to the paper, smaller pseudosuchians lived alongside larger apex predators.

Parvosuchus aurelioi fossils consist of a partial skeleton, including a complete skull, which includes the lower jaw, 11 dorsal vertebrae, a pelvis, and partially preserved limbs.

PHOTO: Fossil skull of Parvosuchus aurelioi under mechanical preparation.

Fossil skull of Parvosuchus aurelioi under mechanical preparation.

Janaina Brand Dillmann

The remains were covered by a thick layer of rock, with only a few pieces of beads visible at first glance, Müller said. After using acid solutions and pneumatic hammers during the preparation process, parts of the cranium popped out of the rock, revealing a complete skull, he added.

“The moment I realized that the skull had been embedded in the rock was amazing,” Müller said. “As I slowly removed a layer of stone, part of the rim of the orbit was revealed. It seemed to me that this animal was looking at me, as if it had been waiting all these endless years to tell its story.”

The skull is less than 6 inches in length and contains long thin jaws with sharp teeth that curve backward, as well as several cranial openings.

Müller estimates that the animal was about 6.5 meters long and had a long tail. It likely stood on four legs that were adapted for walking on land and had blade-like teeth that could tear flesh.

PHOTO: Fossil of Parvosuchus aurelioi.

Fossil of Parvosuchus aurelioi.

Janaina Brand Dillmann

The fossil also had a lightly built skeleton, indicating the animal was a skilled hunter, Müller said.

After carefully examining “every anatomical detail” of the fossil, the researchers noticed features not seen in other similar animals, Müller said.

“At this point, it was clear that I had a completely unknown species on my hands,” he said.

PHOTO: Artist's reconstruction of two individuals of Parvosuchus aurelioi in a Triassic landscape.

Artistic reconstruction of two individuals of Parvosuchus aurelioi in a Triassic landscape.

Matheus Fernandes

There is no clear evidence of what led to the extinction of gracilissuchids, but a plausible hypothesis would be competition with the first dinosaurs or climate changes that occurred during the late Triassic period, when the earth warmed due to massive volcanic eruptions that released large amounts of carbon dioxide into the atmosphere.

Its name is derived from the Latin words “parvus” for “small” and “suchus” for “crocodile” and was also named to honor paleontologist Pedro Lucas Porcela Aurélio, who discovered the fossil material.

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