Paleontologists in Brazil have discovered a previously unknown archosauroid species that thrived approximately 240 million years ago. This intriguing species may belong to a little-understood group of ancient reptiles reminiscent of the ancestors of crocodiles and dinosaurs.
Silescerida acristatata resided in what is now Brazil during the Middle Triassic Period, a crucial time when life on Earth was diversifying following the mass extinction at the end of the Permian Period.
During this era, archosaurs—a diverse group of reptiles that eventually evolved into dinosaurs, pterosaurs, and crocodiles—began to dominate terrestrial ecosystems.
The newly discovered species is likely linked to a rare and poorly understood group known as Euparkeriidae.
Among the most recognized species of Euparkeriidae is Eupacheria capensis, first described in South Africa in 1913 and remains the sole definitive member of this intriguing group.
“The Euparkeriidae are primarily noted for their distinctive stalked archosaurs. Eupacheria capensis existed during the Early to Middle Triassic in South Africa and is the only established member of this clade,” stated lead author Mauricio García from the Federal University of Santa Maria and his colleagues.
“Other presumed euparckerids have been found in regions across China and Europe.”
“Eupacheria capensis and Euparkeriidae rank just outside of archosaurs in all major phylogenetic analyses, highlighting their significance in understanding archosaur origins.”
“This species, along with other potential euparkerids, holds substantial implications for understanding the evolutionary trajectory of archosaurs, as it closely resembles the body plan of archosaur ancestors.”
The skeletal remains of Silescerida acristatata, including its left shoulder blade, right hip bone, and a left femur measuring around 17.3 cm in length, were discovered at a site in Doña Francisca, Rio Grande do Sul, Brazil.
Based on examinations with related species, the new find likely resembled a long-limbed, agile lizard-like predator.
The discovery of Silescerida acristatata broadens the known geographical range of the Euparkeriidae lineage, and reaffirms South America’s vital role in the early evolution of archosaurs.
“This discovery not only provides insight into the temporal and paleogeographical distribution of Euparkeriidae but also illuminates the origin and early evolution of this family. Eucrocopodan represents the first record of this archosaur in the Brazilian Triassic,” concluded the paleontologists.
“More broadly, this new species underscores the significance of South American Triassic deposits in the evolutionary history of archosaurs.”
The team’s research paper was published in the journal Scientific Reports on June 10th.
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García, M. S., et al. 2026. A new euparkeriid form from the mid-Triassic period of southern Brazil, a member of the family Euparkeriidae. Scientific Reports 16, 16585; doi: 10.1038/s41598-026-53740-9
Source: www.sci.news
