Page 6 - valerio agnesi - geographical-phisical aspect Sicily

28 Agnesi: Sicily in the last one million years

affected by difficult connections, often extremely discontinuous, with emerged continental
areas. The poor diversification of association and the geographic distribution of the loca-
tions in which were found mammals remains traced back to this population phase
(Bonfiglio & Burgio 1992) suggest that the emerged lands were significantly less extend-
ed than today and that paleogeography was much more fragmented, perhaps consisting of
emerged areas separated by narrow sea straits, by lagoons or ponds that actually were bio-
geographic barriers.

The provenance of the mammals of the faunal complex of Elephas falconeri is still
unknown, therefore it is still uncertain if the paleo Sicilian-Maltese archipelago had, in those
times or just before, geographical connections with Africa and/or the Italian peninsula.

In the late middle Pleistocene the paleogeographic situation must have been very differ-
ent. The island had reached conditions very similar to present and was populated by a mam-
mals association well differentiated and balanced under the trophic point of view: there are
both big and medium herbivores, as the rather moderate size elephant, Elephas mnaidrien-
sis, a hippopotamus, a wild ox, an aurochs, which is the only species with clear boreal affini-
ties present on the island, two species of deer and predators as wolf, bear, tiger-wolf and
lion. Such association shows not too significant endemic characteristics, in fact, except for
Megaceroides carburangelensis, all herbivores are just slightly smaller than their continen-
tal equivalent, and they are extremely similar, though impoverished, compared to associa-
tion of mammals that lived on the Italian peninsula during the same period.

In numerous sites, faunal elements and associations of this complex date around
200,000 years B.P. (Bada & al. 1991), while other age determinations recently carried out
on analogous faunal association found in Contrada Fusco (Siracusa) have established an
average period going from 147,000 and 88,000 years B.P. (Rhodes 1996). These periods
roughly coincide with the isotopic stages 7,6 and 5 and mostly agree with stratigraphic
relations between deposits containing the association of Elephas mnaidriensis and the
marine terraces in eastern Sicily (Bonfiglio 1991; Bonfiglio & Insacco 1992). Yet, the old-
est finding of an elephant connected to this faunal complex seems to prove that in early
times (maybe around 450-400,000 years ago) there were favourable conditions for animals
coming from Southern Italy, along the migration route, or an equivalent one, used after-
wards by numerous other animals and by man during the Upper Paleolith and Mesolithic.

During temperate climatic phases (isotopic stages 11?, 9, 7, 5) the island was probably
woody, as shown by the presence of abundant fossil remains of deer, as well as bear and
wild pig of this period and by the scarce presence of pollen found in the above-mentioned
Contrada Fusco (Arobba 1996). The sea used to reach higher levels than today’s, as wit-
nessed by marine deposits outcropping on surface at various altitudes near the coast. The
intense pedogenetic activity had caused the formation of typical hot-temperate climate
soils that, in areas where substratum consists of calcareous rocks, become reddish (terre
rosse) and are usually on terraced marine deposits.

During glacial phases (isotopic stages 10?, 8, 6, that is last two to Rissian glaciation),
most of the continental platform emerged forming wide coastal plains, probably occupied
by shrubby steppe, even though woods were always present at least in certain sectors of
the island. The climate, by now colder and more arid, caused degradation of vegetation and
favoured rather active winds, responsible indeed for the formation of aeolian deposits.