The ecological origin and early evolution of snakes has long been a focus of multiple research fields and remains one of the most enduring and controversial topics in biology. Conflicting ecological hypotheses for early snakes, including aquatic, terrestrial, semifossorial, fossorial, or even multiple habitats, have been proposed on the basis of analyses of various traits. To address the paucity of well-preserved snake fossils, a team of scientists from the University of Helsinki and the University of Toronto Scarborough applied a different hypothesis based on high-definition brain reconstructions of modern snakes and lizards. Their predictive models revealed a burrowing lifestyle with opportunistic behavior at the origin of the earliest snakes.
Snakes are fascinating creatures, forming about one-eighth of vertebrate animals found on land.
They come in a wide range of forms and sizes and have adjusted to different ways of life, such as living underground, on the land, in water, and up in trees.
However, the early evolution of snakes and the changes in their morphologies over time has been long debated in the field of biology.
To help unravel this mystery, University of Helsinki’s Dr. Simone Macrì and colleagues used a different way of studying snake evolution.
“Instead of relying on rare, old fossil remains to learn about the history of snakes, we looked at the brains of living reptiles and traveled back in time, thanks to modern imaging and analysis tools,” Dr. Macrì said.
By using high-definition 3D models of modern lizard and snake brains, the researchers reconstructed the brain shape of early snakes and discovered that they were fully adapted for underground living.
Nevertheless, early snakes also displayed versatile behaviors, as evidenced by the mixture of different features and complex patterns in their brain morphologies, which may reflect differences in what they eat, how they use different environments both below and above the ground, and…
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