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Study Reveals Ancient Anacondas Size Surged, Then Stagnated

12/2/2025

Summary

Story summary

A University of Cambridge-led study analyzed 12.4-million-year-old Venezuelan anaconda fossils and found lineage peaked in Middle Miocene and has remained large.
Researchers measured 183 vertebrae from at least 32 individuals and found they averaged 4 to 5 meters.
Lead author Andrés Alfonso-Rojas said ancient anacondas were not larger than today, challenging size-evolution assumptions.
The findings are published in the Journal of Vertebrate Paleontology.

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Story summary

A University of Cambridge-led study analyzed 12.4-million-year-old Venezuelan anaconda fossils and found lineage peaked in Middle Miocene and has remained large.
Researchers measured 183 vertebrae from at least 32 individuals and found they averaged 4 to 5 meters.
Lead author Andrés Alfonso-Rojas said ancient anacondas were not larger than today, challenging size-evolution assumptions.
The findings are published in the Journal of Vertebrate Paleontology.