Cephalopods

Researchers at the Okinawa Institute of Science and Technology have revealed how squid and cuttlefish survived the Cretaceous-Paleogene mass extinction by retreating to oxygen-rich deep-sea refuges. Their analysis of newly sequenced genomes shows these cephalopods originated in the deep ocean over 100 million years ago, followed by rapid diversification into shallow waters. The findings, published in Nature Ecology & Evolution, provide the first comprehensive evolutionary tree for decapodiform cephalopods.