Sauropod dinosaurs have generally been considered to have auditory capabilities comparable to those of other large-bodied animals, both extinct and extant. This inference was based on both their massive body size and the length of the lagena, both of which correlate with the auditory capabilities in extant species, particularly in birds. However, the best hearing frequencies inferred from the size of the lagena in sauropods remains poorly studied. Here, we analysed the auditory capabilities of Sidersaura (MMCh-Pv 70), a rebbachisaurid sauropod from the Upper Cretaceous of Patagonia, based on the morphology and length of the lagena, and estimations of its body mass. With a lagena length of 8.79 mm, the estimated best hearing frequency of Sidersaura is 1333 Hz, whereas its upper hearing limit reaches 3501 Hz. With an estimated body mass of 13511 kg, based on an extrapolation of an estimation based on the length of the tibia, with an increasing factor of x4.09 derived from the estimations in the specimen MMCh-Pv 236 (which, for this specimen, and estimated following two independent approaches, are 20211 kg and 4946 kg, respectively), these frequencies in MMCh-Pv 70 decrease to 1222 Hz and 3111 Hz, respectively. These values exceed those of other large-bodied dinosaurs, including non-sauropod herbivorous and carnivorous taxa. Interestingly, the hearing capabilities of Sidersaura are comparable to those of small theropods, such as Velociraptor, Citipati, and Byronosaurus. The high-frequency hearing capabilities of Sidersaura may have enabled it to detect calls from its nestlings and/or potential predators of the latter.

Ministerio de Ciencia, Innovación y Universidades (España)

NextGenerationEU

European Union

Peer reviewed