REVISION AND RE-DOCUMENTATION OF M. AIROLDI'S SPECIES OF ARCHAEOLITHOTHAMNIUM FROM THE TERTIARY PIEDMONT BASIN (NW ITALY)

Airoldi (1930, 1932) described twenty-three fossil Corallinales (Rhodophyta) from the Oligocene of the Tertiary Piedmont Basin (NW Italy), containing thirteen new species. In this paper Archaeolithothamnium praeerithraeum Airoldi 1932 and Archaeolithothamnium statiellense Airoldi 1932 are re-documented and re-described. The features observable in the sporangial compartments allowed to attribute both species to the genus Sporolithon.&nbsp

REVISION AND RE-DOCUMENTATION OF M. AIROLDI’S SPECIES OF MESOPHYLLUM FROM THE TERTIARY PIEDMONT BASIN (NW ITALY)

Airoldi (1930, 1932) described twenty-three fossil Corallinales (Rhodophyta) from the Oligocene of the Tertiary Piedmont Basin (NW Italy), including thirteen new species. In this paper Mesophyllum fructiferum Airoldi 1932 and Mesophyllum obsitum Airoldi 1932 are re-documented and re-described. The presence of cell fusions, multiporate conceptacles and a ventral core of cell filaments passing from coaxial to non-coaxial confirm that both species belong to the genus Mesophyllum.   SHORT NOTES &nbsp

OLIGOCENE CORAL AND ALGAL REEF AND RELATED FACIES OF VALZEMOLA (SAVONA, NW ITALY)

The  terrigenous and carbonate sediments of the transgressive Oligocene cycle of the Tertiary Piedmont Basin outcropping in the area of Valzemola(Savona, western Liguria, Northwest Italy) and which are referable to the Molare Formation are analysed. The terrigenous sequence, represented by breccias, conglomerates and sandstones, overlies with an angular unconformity dolomitic or calcareous-dolomitic lithologies referable to the San Pietro dei Monti Dolomite Formation. These sequences are locally characterized by rich associations of coralline algae and corals, which by providing a stable substrate allowed the development of a true reef build up. Subsequently the bioherm was suffocated by fluvial sandstone and conglomerate. This may be associated with an intensification in the amount of terrigenous material being brought into the basin. A progressive shallowing continues until the introduction of conditions suitable for calcareous deposition in an intertidal or supratidal environment. The analysis of this reef deposit was carried out by examining seven stratigraphic sections. The paleoecological study of the coral fauna and the algal assemblage, the latter characterized by the significant presence either of the genus Lithophyllum, or of Lithothamnion, allowed some hypothesis on the environmental conditions which characterized this sector during the Late Oligocene. Nine different facies could be shown, from those seven directly connected to the reef and two to nearshore environments proving a regressive phase. Facies I: conglomeratic-sandstone representing a stage of colonization in a dominantly terrigenous environment. Facies II: coral framestone, representing a stage of diversification ("an inner reef front" near to the "reef crest"). Facies III: coral bafflestone representing a colonization stage in an "inner reef slope". Facies IV: coral bindstone representing a stage of domination in a "reef crest" environment. Facies V: coral bindstone alternating with floatstone, gives evidence of a colonization stage in a carbonate environment. Facies VI: coral and algae floatstone, representing a facies of accumulated reef debris. Facies VII: coral rudstone, representing an accumulation facies comparable with that of the "rubble & pavement zone" of the back reef. Facies VIII: conglomerates and sands of a shallow marine environment, represent a regressive sequence. Facies IX: massive limestones with undulated-zoned structures, rhizoliths, calcite veins and pisoliths, evidence of an intertidal or supratidal environment

ARCHAEOLITHOTHAMNIUM AIROLDII NOMEN NOVUM EX LITHOTHAMNIUM STEFANINII AIROLDI

New investigations carried out on the samples which allowed Airoldi, in 1932, to establish the species Lithothamnium stefaninii, showed morphological and structural characters pointing to the attribution of the taxon to the genus Archaeolithothamnium; since Archaeolithothamnium stefaninii was preoccupied 'by Raineri in 1929, for another species, it is necessary to change the specific name of the taxon under discussion to Archaeolithothamnium airoldii

LITHOPHYLLUM GIAMMARINOI SINONIMO PIÙ RECENTE Dl LITHOPHYLLUM CONTII DELL'OLIGOCENE LIGURE-PIEMONTESE

The revision of holotypes and paratypes of Lithophyllum contii Mastrorilli, 1967 and Lithophyllum giammarinoi Mastrorilli, 1 968, coming from the Rupelian calcarenitic limestone of the "Molare Formation" (Tertiary Piedmont Basin), demonstrates that there are not enough elements to permit the distinction of two different species. So, according to priority, Lp. giammarinoi must be consider junior synonym of Lp. contii, that is here redescribed as Lithophyllum contii Mastrorilli sensu amplo

<em>LITHOPHYLLUM IPPOLITOI</em>. A NEW SPECIES OF CORALLINE ALGAE FROM TERTIARY PIEDMONT BASIN

A new species of the genus Lithophyllum (Lithophyllum ippolitoi) was discovered in the Oligocene section of Toleto (Molare Formation, Tertiary Piedmont Basin). The holotype overgrows a coral colony, and is characterised by morphological features and dimensions of cells that are clearly different from those of the other recorded species of Lithophyllum

NEW OBSERVATIONS ON THE ANATOMY OF THE FOSSIL CALCAREOUS ALGA SUBTERRANIPHYLLUM ELLIOTT

New specimens of Subterraniphyllum thomasii Elliott collected from the Oligocene Molare Formation outcropping close to Alessandria (northern Italy) and studied in thin sections and by SEM showed that primary pit-connections, cell fusions, uniporate conceptacles and geniculate branches were present. These new observations collectively confirm the placement of S. thomasii within the geniculate Corallinaceae. Although S. thomasii share many diagnostic characters with the Corallinoideae, in particular with the tribe Corallineae (apical position of uniporate conceptacles, number of medullary cell layers) and some similarity with the Metagoniolithoideae (medullary cells gradually merging into the cortical cells) the lack of information on genicula and the observed details of insertion of branches do not allow to determine the suprageneric disposition of S. thomasii.&nbsp

THREE NEW SPECIES OF CORALLINE ALGAE (GENERA <em>LITHOTHAMNION</em> AND <em>LITHOPHYLLUM</em>) FROM THE TERTIARY PIEDMONT BASIN

Two new species of the genus Lithothamnion and one of Lithophyllum were discovered in the burdigalian section of Bric Cardinelle (Visone Formation, Tertiary Piedmont Basin). The holotypes are present in rhodoliths coming from oncolitic rudstone or calciruditic bodies. The new species are characterised by morphological features and dimensions of cells that are clearly different from those of the other recorded species of Lithothamnion and Lithophyllum

Lithophyllum ippolitoi, a new species of coralline algae from Tertiary Piedmont Basin.

none3FRAVEGA P; PIAZZA M; VANNUCCI GFravega, Patrizia; Piazza, Michele; Vannucci, GRAZIA MARI