Squids ruled the oceans 100 million years ago

Squid first emerged about 100 million years ago and quickly established themselves as the top predators in ancient oceans, according to fossils from more than 260 specimens digitally extracted using a high-resolution tomography technique from Cretaceous rocks from Japan. The study, led by Hokkaido University, is published in the journal Science. Using the technique of ' digital fossil mining ', which allows entire rocks to be digitally scanned to reveal the fossils hidden inside in 3D , researchers identified the beaks of 263 ancient squid , some of which belonged to 40 never-before-seen species . "Both in number and size, these ancient squid clearly dominated the seas ," notes Shin Ikegami, lead author of the study. "Their body size was on par with that of fish and even larger than the ammonites we found alongside them. This shows us that squid thrived as the most abundant swimmers in the ancient ocean ." The research also revealed that the two main groups of modern squid , the near-shore Myopsida and the open-ocean Oegopsida , were already present around 100 million years ago . Until now, it was thought that squid only began to thrive after the mass extinction that ended the age of the dinosaurs around 65 million years ago. The new study shows that squid had already emerged and diversified exponentially by that time.