Taxodium dubium

Martinetto, Edoardo & Macaluso, Loredana, 2018, Quantitative Application Of The Whole-Plant Concept To The Messinian - Piacenzian Flora Of Italy, Fossil Imprint 74 (1 - 2), pp. 77-100 : 83-84

Taxodium dubium whole - plant

Taxodium dubium (STERNBERG) HEER (foliage shoot, cone, seed); Taxodium - type pro parte (pollen)

Text-fig. 6a–g

M a t e r i a l. The Messinian sites only provided shoots. Five Pliocene sites provided a few types of remains, only at Villafranca d’Asti – RDB Quarry were there large quantities; less abundant shoot and cone specimens at: Arboschio, Castelnuovo Don Bosco, Meleto and Santa Barbara ( Fischer and Butzmann 2000, Forno et al. 2015, Teodoridis and Gregor 2001). The pollen grains of the Taxodium dubium whole-plant are not distinguished from those of the Glyptostrobus europaeus whole-plant, and are subsumed under the Taxodium - type, frequent in most of the Messinian to Zanclean samples.

R e m a r k s. The fossil-species name Taxodium dubium was first used for foliage shoots, but its application to a Whole- Plant Concept has already been discussed by Kunzmann et al. (2009), who reported the co-occurrence (line of evidence RCO) of most of the organs. In a few Italian sites several parts co-occur: foliage shoots ( Text-fig. 6a ), cones ( Text-fig. 6b ), seeds ( Text-fig. 6d ), and pollen referred to the “ Taxodium - type ” ( Text-fig. 6f ). Conversely, the stem parts ( Text-fig. 6c ) and pollen cones ( Text-fig. 6e ) of the Taxodium dubium whole-plant have not yet been reported. The habitus of this ancient plant, by considering the phylogenetic framework ( Lu et al. 2014), is necessarily similar to that of Glyptostrobus (see above), yet with globose cones. The fossil Taxodium dubium certainly had a similar habitus ( Text-fig. 6g ) as its living relative Taxodium distichum .

Figures

Text-fig. 6. Identity plate of the Taxodium dubium whole-plant. a) foliage shoot, Castelnuovo Don Bosco, Piacenzian (from Bertini and Martinetto 2014). b) cone from Villafranca d’Asti – RDB Quarry, Piacenzian. c) remains of woody axes missing. d) seeds from the same site. e) remains of amenta missing. f) Taxodium-type pollen from Rio Maior (photo by M. Vieira, Portugal: Vieira et al. 2018), Piacenzian. g) reconstruction of the Taxodium dubium whole-plant based on line of evidence ISA (drawing L. Macaluso). Scale bar 10 mm for a, 1 mm for b, d and 20 µm for f.