THE LOST CETACEANS OF AMEGHINO: A REVIEW OF QUATERNARY MYSTICETES FROM THE ARGENTINE PAMPAS

Florentino Ameghino described in 1891 the new species Balaena pampaea and the new genus Notiocetus, with the new species N. romerianus and N. platensis. These taxa were based on isolated tympanic bullae coming from different Pleistocene fossiliferous localities of Buenos Aires Province, Argentina. However, since their original description, the specimens were considered lost, and subsequent authors were not able to review the specimens at first hand. Based on the descriptions and illustrations provided by Ameghino for Balaena pampaea and Notiocetus romerianus (N. platensis was very briefly described, but not illustrated), most authors considered them as valid taxa. The finding of the holotype specimens of Balaena pampaea, Notiocetus romerianus, and N. platensis allows to reevaluate the morphology and validity of these taxa. Notiocetus platensis is based on a partial bulla of an indeterminate mysticete. Balaena pampaea and N. romerianus are very similar to each other, and are re-identified as belonging to an indeterminate balaenid. Previously noted differences are most-likely the result of preservational artifacts or intraspecific variations. We also include brief comments on isolated bullae of other Pleistocene and Holocene mysticetes that were studied by Ameghino, but which remained unpublished up to the date. In this contribution we aim to highlight that paleontological collections preserve much more than samples of our planet’s past. Many of the preserved specimens have a value that goes beyond their biological value, since they have a cultural background that is part of the history of our discipline.