United Kingdom — Egham scientists have come up with compelling new evidence to prove how dinosaurs really became extinct.
A team of researchers from the department of Earth Sciences and the School of Biological Sciences at Royal Holloway University (RHU) have produced evidence which refutes the theory dinosaurs were wiped out by wildfires triggered by an asteroid impacting the Earth 65 million years ago.
Scientists at the university had previously shown there was no charcoal in the impact layers to support the idea of vegetation fires.
In their latest research project, the team has demonstrated, from the abundance of a group of chemicals called pyrosynthetic Polycyclic Aromatic Hydrocarbons (pPAHs) in the rocks where the asteriod impacted, that the combustion products were not produced by vegetation fires but by the vaporization of oil source rocks at the impact site.
Co-author of the paper Professor Scott said: While it is quite possible that there were some local fires and indeed, these can occur at any time across the Earth we do not see evidence of burnt soils, peat or any other evidence of erosion following the proposed global fire as one might expect.
“Instead the new chemical data provides compelling evidence that a significant volume of oils were combusted during the K-T impact event.
A RHU spokesman said: While it is widely believed that an asteroid impact at the end of the Cretaceous Period was responsible for the extinction of the dinosaurs, many scientists believe that there may have been multiple causes.
The original theory
The popular wildfires theory had developed from the occurrence of soot and chemicals in the boundary layers of the impact site, which is centred on Chicxulub in Mexico.
This Cretaceous-Tertiary boundary, or K-T boundary, marks the extinction of the dinosaurs and is thought to be associated with the impact of an asteroid because the sedimentary rocks of this layer contain large quantities of the element Iridium.
This geological boundary also divides the Cretaceous Period from the beginning of the Tertiary.