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Snakes on a plain: Chinese-led study shows when the serpents shed their legs
- Comprehensive genome survey has determined that the reptiles descended from lizards when dinosaurs roamed the Earth
- Researchers who identified factors in limb loss, hope discoveries boost knowledge of biological development, antivenom drugs
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New research has shown that snakes – those creepy coils of countless nightmares – used to look a lot different.
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According to the largest genome survey of its kind, snakes used to have legs.
The new study, led by researchers at the Chinese Academy of Sciences, has found that snakes originated during the Early Cretaceous – some 118 million years ago – when dinosaurs dominated the Earth.
The ancestors of snakes are lizards, a group of reptiles that rapidly diversified after a mass extinction event about 65 million years ago – a catastrophe that claimed three-quarters of life on Earth, and which included the extinction of dinosaurs.
Snakes have undergone various evolutionary changes, including limb loss, lengthened bodies, and changes in their asymmetrical lungs and sensory systems, according to the new study, which was published Monday in the peer-reviewed journal Cell.
The authors identified genes, regulatory elements and structural variations that have contributed to evolutionary changes in snakes by analysing 14 genomes from 12 families of snakes, which account for about 84 per cent of all snake species.
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