Data and code associated with the papers 'Ecological not social factors explain brain size in cephalopods' (https://www.biorxiv.org/content/10.1101/2024.05.01.592020) and 'A phylogeny of extant coleoid cephalopods with brain data' (https://www.biorxiv.org/content/10.1101/2024.04.29.591691)