化石粪便揭示古松鼠的广泛食性
When we picture squirrels, we imagine them nibbling nuts and seeds. But ancient relatives of today's ground squirrels had a much more varied menu. Analysis of fossilized excrement, known as coprolites, suggests these small mammals scavenged the carcasses of large Ice Age animals. This unexpected finding challenges our understanding of small mammal behavior in prehistoric ecosystems.
Scientists extracted and sequenced DNA from coprolites found in frozen sediments or ancient caves. These samples were dated using volcanic ash layers, confirming they were hundreds of thousands of years old. The genetic material revealed exactly what the squirrels had consumed, providing a direct window into their diets. This method bypasses the need for fossilized stomach contents or tooth wear analysis. Without such direct evidence, scientists previously relied on indirect clues like jaw structure to guess what extinct animals ate.
Inspired by Scientific American reporting · Rewritten by Vocabsavvy · Vocabsavvy Original (inspired-by attribution)