The skeleton of Navaornis hestiae, an 80-million-year-old hen fossil
S. Abramowicz/Dinosaur Institute/Pure Historical past Museum of Los Angeles County
An 80-million-year-old fossil hen has been found with a cranium so exquisitely preserved that scientists have been in a position to examine the detailed construction of its mind.
In each age and evolutionary improvement, the brand new species, named Navaornis hestiae, is sort of halfway between the earliest recognized bird-like dinosaur, Archaeopteryx, which lived 150 million years in the past, and trendy birds. It lived within the Cretaceous Interval alongside dinosaurs akin to Tyrannosaurus and Triceratops.
The fossil, which bears a superficial resemblance to a starling, was discovered close to Presidente Prudente, Brazil, in 2016 and was instantly recognised as vital due to the rarity of a full hen skeleton, significantly certainly one of that age.
However Daniel Discipline on the College of Cambridge says it wasn’t till 2022 that he and his colleagues realised the cranium was so intact that they may presumably scan it and create a 3D mannequin of its mind.
Excessive-resolution CT scanning permits palaeontologists to see inside fossils. “This involves careful ‘digital dissection’: separating out each individual component of the skull and then reassembling them into a complete, undeformed three-dimensional reconstruction,” says Discipline.
“The new fossil provides unprecedented insight into the pattern and timing by which the specialised features of the brain of living birds evolved.”
Based mostly on the crew’s reconstruction of the mind, Discipline says the cognitive talents and flying capability of Navaornis had been in all probability inferior to these of most dwelling birds.
Artist’s impression of Navaornis hestiae
J. d’Oliveira
The parts of the mind liable for advanced cognition and spatial orientation aren’t as enlarged as these of contemporary birds, he says.
“Although the cerebrum of Navaornis is greatly expanded relative to the condition in a more archaic bird relative like Archaeopteryx, it is not as expanded as what we see in living birds.”
The enlarged brains of contemporary birds assist an enormous vary of advanced behaviours, says Discipline, however understanding how their brains developed has been difficult as a result of a scarcity of adequately full and well-preserved fossil hen skulls from early hen relations.
“Navaornis fills a roughly 70-million-year-long gap in our understanding of how the distinctive brains of modern birds evolved.”
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