Thuja, C.Linnaeus, 1753

Martinetto, Edoardo, Bertini, Adele, Mantzouka, Dimitra, Natalicchio, Marcello, Niccolini, Gabriele & Kovar-Eder, Johanna, 2022, Remains Of A Subtropical Humid Forest In A Messinian Evaporitebearing Succession At Govone, Northwestern Italy - Preliminary Results, Fossil Imprint 78 (1), pp. 157-188 : 168

“ Thuja ” saviana (C.T.GAUDIN) C.T. GAUDIN, 1859

Text-fig. 5a , Pl. 1, Figs 8, 9

M a t e r i a l. Two leafy shoots from GLAz (MGPTPU141007, MGPT-PU141008), one from GLA20 (MGPTPU141093) and another from GLA30 (MGPT-PU141094).

D e s c r i p t i o n. Plagiotropic leafy shoots with dimorphic decussate scale leaves, with broad facial leaves and lateral ones usually not touching each other at the base.

R e m a r k s. The shoots seem to be identical to the Miocene shoots from central Italy on which Gaudin and Strozzi (1859) based their fossil-species Thuja saviana . However, the general picture is complicated by the association of such shoots in the type locality ( Gaudin and Strozzi 1859: pl. 1), and in a Spanish site ( Barron and Diéguez 2001) with cones that may belong to Calocedrus . Therefore, it is suspected but not proved, that the type of T. saviana may belong to Calocedrus (see also Kvaček et al. 2020 for the fossil record in Europe), a hypothesis further supported by the fact that cones with diagnostic characters for Thuja have never been reported for the Neogene of Italy. Their rather typical morphology suggests applying a name which is precise and in the meantime indicates the ambiguous generic placement (i.e., not Cupressaceae gen. et sp. indet., but cf. Thuja saviana or “ Thuja ” saviana ).

The shoots of “ Thuja ” saviana are similar to another common type of shoot found in the Italian Messinian, which has lateral leaves touching each other at the base ( Guglielmetto and Iguera 1994), and has been assigned to Chamaecyparis sp. ( Teodoridis et al. 2015a, b). This identification receives support from the occurrence of Chamaecyparis cones and seeds in the Italian Neogene (but only in Pliocene sites; e.g., Martinetto et al. 2018b), even if they have not yet been described in detail. We hope that future cuticular studies will permit a more definite generic assignment of both types of shoots.

Figures

Text-fig. 5. Plant fragments from Govone with evidence of preserved cuticle. a: Decussate pair of leaves of “Thuja” saviana (C.T.GAUDIN) C.T.GAUDIN with a window (arrow) opened in the brownish cuticle, showing the yellowish mesophyll cells and some possible resin canals (dark), MGPT-PU141094. b: Angiosperm leaf fragment (from sample MGPT-PU141017) under the stereomicroscope, showing the blackish compressed mesophyll on the right and patches of cleaned, yellowish cuticle at the top (arrow). Scale bar 1 mm.