Did large foraging migrations favor the enormous body size of giant sauropods? The case of Turiasaurus

Abstract

We propose that the huge sizes attained by many sauropod dinosaurs can be explained in the context of a climate characterized by pronounced seasonal changes. Under these conditions, the large herbivores would have become migratory, forced to move great distances during the drier times of year, in which case large body size becomes an adaptive advantage, since large home ranges and the ability to travel great distances increase with size. In this way, the need for a large foraging radius is a potent source of selection for larger size, and the capacity for sauropods to migrate and explore new territory was significantly higher than in extant herbivores. Examples discussed are Turiasaurus riodevensis and Camarasaurus lentus; some of their anatomical structures, such as vertebral neural extensions and crests associated with nasal cavities, can also be explained under this scenario, as adaptations to drought conditions.