Daniel Zoboli

Vertebrate and Invertebrate Trace Fossils in the Late Pennsylvanian (Carboniferous) Fluvio-Lacustrine San Giorgio Basin (South-West Sardinia): Remarks on the Oldest Continental Ichnoassociation of Italy

ABSTRACT A new study of the ichnotaxonomy and palaeoecology of the Late Pennsylvanian San Giorgio Basins trace fossils was carried out. The tetrapod tracks were attributed to Batrachichnus salamandroides and to indet. tracks with a possible small temnospondyl and/or lepospondyl affinity. The invertebrate trace fossils include locomotion traces (Diplichnites isp.), grazing traces (Cochlichnus anguineus), and feeding structures (Treptichnus bifurcus, Treptichnus isp.). The trace fossils were evaluated by means of ichnofacies, highlighting a transitional Scoyenia-Mermia ichnofacies, typical of Carboniferous freshwater settings. The trace fossil co-occurrence and taphonomy was utilized to give a new interpretation of the fossil-bearing lithofacies, which are dolomitic mudstones-fine sandstones expression of marginal lacustrine environments repeatedly subject to flooding (three different ichnoassociations highlight different bathymetry/emersion). This is the oldest continental ichnoassociation of Italy, and its moderately high diversity and complexity suggest further study of this important Carboniferous trace fossil locality.

On the systematic position of the oldest insular ruminant Sardomeryx oschiriensis (Mammalia, Ruminantia) and the early evolution of the Giraffomorpha

Sardomeryx oschiriensis is the oldest insular ruminant known (Burdigalian of Oschiri, Sardinia, Italy). Only two isolated upper dentitions compose the type material. The first phylogenetic hypothesis proposed Sardomeryx to be closely related to the Giraffoidea and especially the Late Miocene Sardinian derived giraffid Umbrotherium. Description of new specimens from Laerru (Burdigalian, Sardinia, Italy), including lower teeth and decidual premolars, leads to a reinterpretation of the phylogenetic position of Sardomeryx and of the early evolutionary history of the Giraffomorpha. Based on our phylogenetic hypothesis, Sardomeryx is nested within the Giraffomorpha as a basal Palaeomerycoidea. Sardomeryx may have originated from south-western Europe before the separation of the Corsica-Sardinia Block during the earliest Miocene. The enigmatic latest Oligocene Bedenomeryx from the south-west France is also considered as a basal (and the most ancient) member of the Palaeomerycoidea. Including Bedenomeryx in the Palaeomerycoidea lineage would place the origin of the Giraffoidea, the sister family of Palaeomerycoidea, within the Oligocene. Bedenomeryx is characteristic of arid south-western France, directly echoing the advanced condition observed in the Sardomeryx dentition (e.g. high crowned teeth, absence of the external postprotocristid on lower molar, reduction in length of the premolar row) typical for insular ruminants in arid environments.

UPPER PLEISTOCENE MAMMAL ASSEMBLAGE FROM SU CONCALI QUARRY (SAMATZAI, SOUTHERN SARDINIA, ITALY)

A mammal assemblage discovered in a fissure filling located in a quarry near the village of Samatzai (Campidano, southern Sardinia, Italy) is described herein. The following taxa are reported: Microtus ( Tyrrhenicola ) henseli , Rhagamys orthodon , Prolagus sardus , Asoriculus sp., Cynotherium sardous and Praemegaceros ( Nesoleipoceros ) cazioti . The assemblage (“ Microtus ( Tyrrhenicola )” Faunal Complex, Dragonara Faunal Subcomplex) infers a Late Pleistocene age and represents the richest deposit of Quaternary mammals reported in the central Campidano area.