Cretaceous-period dinosaurs had to deal with greater seasonal differences than previously thought. Image credit: Sergey Krasovskiy.
SciNews has a piece about the climate during the end of the Cretaceous Period. Researchers looked at various data, including oyster and rudist shells, to reconstruct a picture of the paleo climate during the Campanian (late Cretaceous Period) about 78 million years ago in what is now modern day Sweden. They found that the climate was much more variable than previously thought, with winters fluctuating between about 15 degrees Celsius (59 degrees Fahrenheit) in the winter to 27 degrees Celsius (80 degrees Fahrenheit) in the summer. Find all the details in a paper which was published in the journal Communications in Earth and Environment.
“We used to think that when the climate warmed like it did in the Cretaceous period, the time of the dinosaurs, the difference between the seasons would decrease, much like the present-day tropics experience less temperature difference between summer and winter,” said lead author Dr. Niels de Winter, a postdoctoral researcher at Vrije Universiteit Brussel and Utrecht University.
“However, our reconstructions now show that the average temperature did indeed rise, but that the temperature difference between summer and winter remained rather constant. This leads to hotter summers and warmer winters.”
To characterize the climate during the Campanian greenhouse period, Dr. de Winter and colleagues examined well-preserved oyster and rudist shells from the ancient coastal localities of the Kristianstad Basin in southern Sweden.
“Those shells grew in the warm, shallow seas that covered much of Europe at the time,” they explained.
“They recorded monthly variations in their environment and climate, like the rings in a tree.”
