What killed off the dinosaurs ? According to a new subject by an international team of researchers , it certainly was n’t volcanic action . Although floods of fire did come out from the Deccan Traps around the metre of the renowned peck extinction effect 66 million yr ago , the chemistry of the ocean shows that they did n’t change the world as much as previously thought .
“ Although Deccan volcanism have a short - lived world-wide warming outcome and some sea acidification , the effects were cancelled out by rude carbon cycling processes long before the good deal extermination that killed the dinosaurs , ” Michael Henehan , a postdoctoral investigator at Yale University and lead source of the field of study , said in astatement .
Mass extinguishing event never have just one reason . They may have a coup de grâce – a huge asteroid in the case of the demise of the non - avian dinosaur – but they always have multiple antagonists .
Paleontologists know this as the Murder on the Orient Express model , appoint after the eponymous Poirotmurder - mystery novelby Agatha Christie in which(spoiler alert)everyone on the engine is behind the grisly homicide . When it come to the dinosaurian mass extinction outcome , one of the most frequently cite extra perpetrator is volcanism , which was consider to have significantly change the chemistry of the oceans andaltered the clime .
However , recent studies havecast some doubton how influential this volcanism was , with one pointing out that the clime would have warm up quickly but would have recall to normal soon after . Now this novel study , published in the journalPhilosophical Transactions of the Royal Society B , has again criticized the melodic theme that volcano were as guilty as some think .
Spinosaurus would have experienced the effect of this monolithic volcanic eruption . Herschel Hoffmeyer / Shutterstock
As it points out , massive volcanism did indeed occur towards the end of the Cretaceous period , pump out continental - sized lava flowing and unleashing immense amounts of C dioxide . Much of this would have find its mode to the oceans , where it would have rick into an acidic chemical compound just as itstill does today .
The research team analyzed sediment cores from the depths of the ocean dating back to this time , looking for signs of broken down calcium carbonate cuticle , pH reduction and other chemic change that would suggest how quickly the ocean acidulate following the onset of the vast volcanism . They ab initio found that there was indeed ocean acidification happening – in fact , it was far more severe and went on for a recollective length than previous mannequin suggested .
However , they also get wind that the oceans were already on their fashion back to normal before the lot extinction event even began to occur . By the time species begin to rapidly die off , the ocean were relatively inhabitable to marine life . So , although volcanism release vast sum of carbon dioxide , it was over too long a timescale to make much of a difference – both on the Din Land and in the sea .
More than anything , this study shows how powerful the asteroid shock actually was : Not only did it create gargantuan tsunami and a huge fireball , but it darken the sky and cool the mood at a remarkable speed . Consequently , up to 75 pct of life died out , including almostall nautical life .
The non - avian dinosaur were actually highly luckless : The asteroid may have destruct them , but something else , perhaps the boost of mammals , wasalready kill them offlong before the space - borne apocalypse arrived .
