New Study Sheds Light on the Evolution of Animals
Published:10 Aug.2023 Source:University of Oxford
Animals first occur in the fossil record around 574 million years ago. Their arrival appears as a sudden ‘explosion’ in rocks from the Cambrian period (539 million years ago to 485 million years ago) and seems to counter the typically gradual pace of evolutionary change. Many scientists (including Darwin himself) believe that the first animals actually evolved long before the Cambrian period, but they cannot explain why they are missing from the fossil record.
To investigate this, a team of researchers led by Dr Ross Anderson from the University of Oxford’s Department of Earth Sciences have carried out the most thorough assessment to date of the preservation conditions that would be expected to capture the earliest animal fossils.
the study suggests a possible maximum age to the origin of animals of around 789 million years: the youngest estimated age of the Svalbard formation. The group now intend to search for progressively younger Neoproterozoic deposits with conditions for BST preservation. This will confirm the age of rocks in which animals are missing from the fossil record because they really were absent, rather than because conditions did not enable them to be fossilised. They also intend to perform laboratory experiments to investigate the mechanisms that underpin clay-organic interactions in BST preservation.