It’s been long thought that prehistoric marine creatures living in the Antarctic when the asteroid hit Earth, were mainly unaffected. But a new study has revealed that they did, in fact, get wiped out along with their land-dwelling peers.

Studying around 6000 marine fossils , a team of researchers from the University of Leeds and the British Antarctic Survey on Seymour Island, dated the fossils at around 65 to 69 million years which indicates that the creatures died at the same time the asteroid hit, according to CNN.

The study was recently published in Nature Communications and took six years to complete giving further insight into the theory of what really happened to the dinosaurs. The new findings show that it is more and more likely that an asteroid was to blame rather than gradual climate change or volcanic shifts.

In the past, scientists concluded that the oceans provided a haven for marine creatures protecting them from the effects of the asteroid but it now seems they were equally exposed to the mass devastation as Jane Francis of the British Antarctic Survey and co-author of the study explained in a press release.

“These Antarctic rocks contain a truly exceptional assemblage of fossils that have yielded new and surprising information about the evolution of life 66 million years ago. Even the animals that lived at the ends of the Earth close to the South Pole were not safe from the devastating effects of the mass extinction at the end of the Cretaceous Period.”

Studying fossils from marine areas is relatively easy as lead author James Witts, a PhD student in Leeds University’s School of Earth and Environment explains.

“Most fossils are formed in marine environments, where it is easy for sediment to accumulate rapidly and bury parts of animals, such as bones, or bodies of creatures with a hard shell. For a dinosaur or other land animal to become fossilized, a series of favorable events are needed, such as for bones to fall into stagnant water and be buried rapidly to prevent decomposition, or be washed out to sea by rivers.”

The range of 6000 fossils the team examined were comprised of one of the richest fossil records of its kind anywhere on the planet from small snails up to gigantic reptiles.