Photo: freepik
An exceptionally well-preserved fossil of an early snake discovered in Brazil has enabled scientists to reconstruct the brain anatomy of a Cretaceous species, offering new insights into the evolution of snakes, Reuters reported.
The newly described species, Tametara mirim, lived around 75–85 million years ago during the Late Cretaceous, when dinosaurs still roamed the Earth. The snake measured about 42 centimeters (16.5 inches) long and inhabited an ecosystem shared with long-necked herbivorous dinosaurs, crocodiles, and birds.
The fossil was unearthed in Brazil's São Paulo state and preserves roughly 60% of the skull and 70% of the vertebral column, according to lead researcher Thiago Simões, an evolutionary biologist at Princeton University.
The remarkably intact skull allowed researchers to reconstruct the animal's brain for the first time. Analysis of its anatomy and bone microstructure suggests Tametara mirim was a burrowing snake, similar in lifestyle to modern coral snakes. The findings were published in the journal Nature.
"This is the first opportunity to investigate the evolution of the central nervous system in early snakes," Simões said.
Researchers noted that Tametara mirim is one of only four known Cretaceous snake species preserved well enough to provide such detailed anatomical information.
The study suggests snake evolution was more complex than previously thought, with early snakes independently adapting to underground, terrestrial, and marine environments rather than following a single evolutionary path.
Scientists believe the species likely fed on insects, although no direct evidence has been found. The fossil also lacks teeth, making it impossible to determine whether the snake was venomous.
While modern snakes are limbless, many early species retained hind limbs. Although these were not preserved in the fossil, researchers believe Tametara mirim may have possessed well-developed rear legs, similar to the ancient snake Najash rionegrina.
The reconstructed brain also indicates that Tametara mirim had smaller cerebral hemispheres and a less developed visual center than most living snakes, consistent with a life spent largely underground, where vision is less important.
