Elisabetta Cioppi

Mediterranean fossil whale falls and the adaptation of mollusks to extreme habitats

The hypothesis that sunken carcasses of Mesozoic marine reptiles and Cenozoic whales acted as evolutionary stepping stones to deep-sea reducing habitats is underlain by the question of whether vent-like, chemosymbiotic specialization fi rst evolved at shelf depths. Fossil skeletons of large whales have long been known from ancient shallow-water strata, but they have never been considered as a source of information on ecosystem development. We present a study on a 3 Ma old fossil whale fall and a survey of other Pliocene fossil skeletons to show that the associated biota is dominated by heterotrophs, with subsidiary chemoautotrophs. The taphonomy of the Mediterranean shelf whale falls shows some differences with respect to deep-water studies. Quantitative analyses of abundance data within a large data set on fossil and modern mollusk families confi rm that deep- and shallow-water communities at reducing habitats are composed of a different set of taxa, i.e., specialists occurring only below the shelf break. Mediterranean carcasses sunken in coastal settings do not seem to be favorable for the evolution of whale-fall specialists among the mollusks. The situation reverses as the shelf break is approached.

Evolutionary Theory and the Florence Paleontological Collections

Florence has a tradition of Natural Philosophy, and since as early as the sixteenth century fossils were collected by the Granduke. The Museum of Natural History of the University of Florence houses today collections that belonged to Nicolas Steno, when fossils were for the first time used as documents to reconstruct Earth history. Natural philosophers and geologists, both Italian and foreigners, continued to study fossils collected in Tertiary strata of Tuscany until the nineteenth century, when the first speculations on the origin of species were proposed. Charles Darwin himself mentions fossil vertebrates that are today on show in our museum. In the last years, this part of the history of science has been proposed to the public. The aim was to foster an understanding of the centrality of fossils in two cultural revolutions, the discovery of deep time and the birth of evolutionary theory–connected among themselves and with the emergence of geology. Dedicated volumes, public conferences, guided visits to the collections, and field trips to paleontological sites have attracted an attentive and responsive public, showing that the history of science can help deliver modern evolutionary thinking. Other activities aimed at students of all ages have also shown that the interaction between schools, university teachers, and museum personnel is vital to form the mind of future generations on the reality of the evolution of natural systems.