Climatic and vegetative conditions varied across the earth 150 million years ago, when dinosaurs flourished confirms carbon dioxide levels from the Late Jurassic Period. This suggests a similarity with our own ecosystems.
"The assumption has been that ancient ecosystems worked just like our modern ecosystems," said paleontologist Timothy S. Myers, from Southern Methodist University, Dallas, who led the study. "We wanted to see if this was, in fact, the case."
Accordingly, Myers analysed fossil soils from the Late Jurassic Period by measuring the ratios of carbon isotopes. His analysis indicated that Jurassic soils contained high levels of CO2 from vegetation, according to a Southern Methodist statement.
Nodules of ancient soil are fairly common in present-day rock, forming as a result of seasonally dry conditions. They harden into mineralised clods, making them easy to spot and sample as they weather out of ancient soil profiles.
From that, Myers was able to infer the presence of lush plant life in certain regions during the Jurassic period. The soils came from locales where scientists previously have gathered animal fossils - North America, Europe and Africa.
Combining the data with the known fossil sampling allowed Myers to confirm that the modern relationship between animals and vegetation held true even millions of years ago.
"Our analysis represents the first time that anyone has tried to apply ecological modelling to this relationship in the fossil record," Myers said.