Sporolithon cf. airoldii (Fravega) Vannucci, Quaranta & Basso, 2010

Dey, Rikee, Basso, Daniela, Chakraborty, Arindam, Roy, Lopamudra, Bhaumik, Ajoy Kumar & Ghosh, Amit K., 2023, Rhodolith-forming coralline red algae in the CaCO biofactory - A case study from the Serravallian of tropical northeastern Indian Ocean, Comptes Rendus Palevol 22 (26), pp. 541-567 : 551

Sporolithon cf. airoldii

( Fig. 5D)

DESCRIPTION

Encrusting to warty growth form, thallus monomerous, dorsiventral, non-coaxial VC. The cells of VC are rectangular in shape that measure 8 to 16 µm in length and 3 to 8 µm in diameter. Cells of PF are more or less squarish with no distinct zonation, 5 to 12 µm in length and 4 to 10 µm in diameter. Cell fusions present. Epithallial cells and trichocytes are indiscernible. Sporangia elliptical, formed within calcified compartments and grouped into sori. Each sporangium measures 80 to 120 µm in height and 35 to 48 µm in diameter ( Table 1 ).

REMARKS

The specimen is comparable to Sporolithon airoldii described from the lower Oligocene of NW Iran ( Basso et al. 2019) in having small size of the vegetative cells and other anatomical features, but the maximum length of the sporangia exceeds that of the specimens described by Basso et al. (2019) as well as the type material of S. airoldii . Vannucci et al. (2010) re-described S. airoldii from the upper Rupelian-Chattian of Sassello while re-assessing Airoldi’s (1932) specimens. Sporolithon airoldii was recorded earlier from the Oligocene of Molare Formation of the Tertiary Piedmont Basin, NW Italy ( Vannucci et al. 2010), from the lower and middle Rupelian of Prasco and Ovrano, Alessandria ( Mastrorilli 1968), Val Lemme, Carrosio, Alessandria ( Fravega et al. 1988), from the upper Rupelian to Chattian of Sassello, Savona ( Airoldi 1932; Fravega et al. 1987), from the upper Burdigalian to Serravallian of St. Florent, N. Corsica and Bonifacio, Cala de Labra, S. Corsica (Mastrorilli in Bellini & Mastrorilli 1975) and from the lower Oligocene of NW Iran ( Basso et al. 2019).