Bobtail and bottletail squids are small marine invertebrates that are easy to collect, reproduce quickly, and can be raised together in large numbers in laboratories, making them useful model animals for research. They're cephalopods—related to true squid, octopus, and cuttlefish, which are renowned for their intelligence and complex behaviors, but of which scientists still know little. Now, in a new study, published in Communications Biology, researchers have used genetic techniques to show that bobtail squid and bottletail squid share a relatively recent common ancestor and that major biogeographic events might have shaped the evolution of the many different species.