Gianni Gallai

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.

PROPOTAMOCHOERUS SP. (SUIDAE, MAMMALIA) FROM THE LATE MIOCENE OF GRAVITELLI (MESSINA, SICILY, ITALY) REDISCOVERED

This paper describes two casts of a suid from the Late Miocene of Gravitelli (Messina, Sicily), originally described by Seguenza in 1902. The entire Gravitelli faunal collection was lost in the early 1900i¦s. The recent rediscovery of two casts in the collections of the Museo di Storia Naturale of the University of Florence represent the only available material from this locality (in addition to the original description and illustration by Seguenza). The study of these casts allow a revision of the Gravitelli suid and its attribution to the genus Propotamochoerus . Although a specific determination is not possible, we suggest probable affinities with the species P. hysudricus or P. provincialis .

SUS SONDAARI VAN DER MADE, 1999 (MAMMALIA, SUIDAE) FROM MONTE TUTTAVISTA (OROSEI, WESTERN SARDINIA, ITALY)

This paper formally describes some cranial and postcranial remains of young and adult fossil suids retrieved from Monte Tuttavista karst fissures (Orosei, western Sardinia). The material is herein attributed to the Sardinian species Sus sondaari Van der Made, 1999. Features of skulls, mandibles, some milk teeth, definitive canines, and thus far unknown post-cranial elements of Monte Tuttavista suids significantly integrate our knowledge of the endemic species Sus sondaari . An emended diagnosis is here proposed, including some new diagnostic features such as lower canine with scrofic section, and oval shape of scapular glenoid fossa. Finally, the challenging evolutionary relationships of Sus sondaari are briefly discussed.