Never has a theropod been this happy to cool down in the twilight air. Concavenator is hypothesized to have used the hump or sail on its back to thermoregulate. I note here that I will continue to refer to it as either a hump or a sail because the illustrations of the dinosaur appear to address both anatomical structures as equally likely to have been present. The main difference is that a hump is generally considered to consist of fatty connective tissues whereas a sail would more likely be a thinly stretched skin supported by bony struts. In this illustration it appears safe to say that this Concavenator is sporting a fatty looking hump rather than a thinly stretched sail. The hump, however, could have potentially served as a thermoregulatory structure in addition to the other common purposes that fatty humps are used for in extant animals: storage of energy and, through metabolic breakdown of fats, the storage of some water reserves. The need for a water source in the Barremian of Spain, from which the fossils were recovered, honestly unknown to me, but having food reserves is always a good idea for any animal. Roger Benson suggested that perhaps the bones supporting the hump were more geared toward being the origin of display structures. I have yet to see this idea illustrated however.