London: Some crocodiles have a sensitive side underneath their tough skin that could shine light on our ancient climate, scientists say. The idea of a clock inside a crocodile was imagined by JM Barrie in the story of Peter Pan.
However, instead of telling the current time, ancient crocodilians could serve as climate “clocks” — proxies to study past climates, in a similar way to the use of tree rings and ice cores. This is possible because scientists have discovered that some species of crocodilian were sensitive to changes in climate while others were more tolerant, according to the study.
Mapping the distribution of these different species using fossil remains could reveal more precise details about what the global climate was like in different locations millions of years ago. “Our analysis suggests that crocodilians are even less of a homogenous group than previously thought and that some alligator-like reptiles were particularly good at tolerating the dramatic changes in climate that marked the end of the Eocene epoch and the beginning of the Oligocene,” said Stephane Jouve from the University of Sorbonne in France. The transition between these epochs was marked by a climatic crisis, during which temperatures plummeted, sea levels fell drastically and many plants and animals became extinct as a result. Previous studies have suggested that crocodilians were one of the species to decline in diversity.
However, the new fossil analysis suggests that while some species did die out, others migrated to warmer waters and some managed to survive. The coastal environment was transformed by the decline in sea level and some marine longirostrine crocodilians escaped the cold of Europe by migrating south to North Africa.
