16.9.05

Stone salamanders preserve climate record

Yellowstone Park fossils show subtle effects of temperature.
Fossil hunters in Yellowstone National Park have discovered an unusual way to record the effects of climate change. Specimens from the past 3,000 years suggest that salamanders have grown bigger as the climate has warmed, and may continue to change as temperatures rise and lakes dry up.

During development, tiger salamanders (Ambystoma tigrinum) can metamorphose and head for land rather than staying in the water. And warmer climes have made salamanders on land outgrow their water-based relatives, says Elizabeth Hadly of Stanford University in California. Hadley and her colleagues examined almost 3,000 salamander vertebrae from the park's Lamar Cave in Wyoming.

The researchers, who publish their results in BMC Ecologyclick here, analysed fossils from 15 different layers of rock in Lamar Cave. They dated the deposits and divided them into five time intervals corresponding to five periods with different climates over the past 3,000 years. (...)

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