Early snakes explored life underground, on land and at sea
Snakes are highly modified lizards, with more than 4,000 living species today. The origin of snakes has long been one of evolutionary biology's most debated questions. Their sparse fossil record has made it hard to pin down what drove the evolution of their limbless body plan.
A new study published in Nature challenges the long-standing debate on the origins of snake limblessness. Researchers reveal that early snakes did not follow a single evolutionary path, but instead experimented with various habitats and sensory strategies. The findings, based on an analysis of fossilized snake species from the Late Cretaceous period, approximately 80 million years ago, demonstrate that these ancient snakes had already achieved remarkable diversity in their ecological adaptations.
The study focuses on two key fossil specimens, Tametara mirim and Dinilysia patagonica, both discovered in Brazil and Argentina respectively. Tametara mirim, known for its exceptionally well-preserved fossil, was found to be adapted to a burrowing lifestyle based on its brain endocast and bone microstructure. In contrast, Dinilysia patagonica exhibited characteristics more suited to life on the ground.
These discoveries, supported by evidence from marine sediments, indicate that different snake lineages explored various habitats, including burrowing, terrestrial, and even marine environments, much earlier than previously thought.
Lead author Tiago Simões of Princeton University and his international team of collaborators combined brain reconstructions with data from living snakes to illustrate that early snakes were not simply evolving towards a modern condition, but rather exploring different sensory and ecological strategies simultaneously. This multifaceted approach to snake evolution suggests that the journey to limblessness was far more complex and varied than earlier hypotheses proposed.
Written by urgent.news from Phys.org's reporting — not their text. Machine-written — it may contain errors, so check the original before relying on it.
