The specific mass extinction event wiping the dinosaurs off the face of Earth was just as fatal to life in the Antarctic, according to a new study.
Scientists from the University of Leeds and the British Antarctic Survey on Seymour Island in the Antarctic Peninsula discovered that the event at the end of the Cretaceous Period killed up to 70 percent of species residing there at that time — contrary to previous beliefs that life in the southernmost regions were spared.
Over six years, the team identified and analyzed over 6,000 marine fossils dating back to 69 million to 65 million years ago. The collection is among the largest to date, including species ranging from clams and snails to large creatures such as the carnivorous lizard Mosasaurus.
They saw a drastic 65 to 70 percent drop in the species populations in the Antarctic region some 66 million years earlier, which coincided with disappearance of the dinosaurs as well as many other animals at the end of the Cretaceous period.
“Our research essentially shows that one day everything was fine — the Antarctic had a thriving and diverse marine community — and the next, it wasn’t,” said lead author and Ph.D. student James Witts, referring to a “very sudden and catastrophic” occurrence on the planet.
The evidence, Witts added, strongly indicates that the primary factor behind the extinction was a massive asteroid impact instead of climate change or extreme volcanism.
Their findings shattered earlier notions that polar creatures were distant enough from the extinction event to be adversely affected, may it be an asteroid impact striking the Gulf of Mexico or severe volcanism in India’s Deccan province.
It seemed too that polar life was not as resilient to worldwide changes linked to asteroid impacts — as assumed by many due to their conditions, including erratic food supply and surviving in darkness for six months at a time.
The impact was sudden for other species, but how about the dinosaurs? Many experts deem the dinosaur fossil data patchy and limited in quantity and diversity, thus unable to prove that their demise was gradual.
According to Witts, most fossils are formed in aquatic surroundings, where sediment amass quickly and bury animal bones or shells. Fossilizing dinosaurs and other terrestrial creatures, however, require certain events — bones washing out to seas via rivers, for instance.
The findings were published in the journal Nature Communications.
This month, a team of international researchers unearthed in Antarctica some dinosaur remains thought to be from 67 million to 71 million years old. After about two years, findings can show the environment the mighty dinos lived in and the conditions leading up to their inevitable end.