Dadoxylon cf. rollei Unger, 1859

Galtier, Jean, Ronchi, Ausonio & Broutin, Jean, 2011, Early Permian silicified floras from the Perdasdefogu Basin (SE Sardinia): comparison and bio-chronostratigraphic correlation with the floras of the Autun Basin (Massif central, France), Geodiversitas 33 (1), pp. 43-69 : 63

Dadoxylon cf. rollei Unger, 1859

( Fig. 10 A-D)

A rather large specimen consists of a single fragment of distorted wood ( Fig. 9A ); however characteristic features are preserved: the files of secondary xylem tracheids (30-50 µm in diameter) are separated by narrow (uniseriate) rays of variable height (2 to 20 cells) ( Fig. 9B, D ); pitting, restricted to radial walls, shows uni- to biseriate rows of crowded circular bordered pits ( Fig. 9C ). This anatomy is similar to that of woody trunks of Dadoxylon rollei Unger from the Lower Permian of Germany and from Autun. Marguerier (1971), who investigated trunks from Autun, consider that characteristics of tracheid pittings of such woods suggest affinities with walchian conifers rather than with cordaites.

Figures

FIG. 10.— Silicified plants from the Permian of Sardinia:A-D, Da-

FIG. 9. — Silicified plants from the Permian of Sardinia: A, Cordaixylon sp., transverse section of a partly decorticated small stem with a solid parenchymatous pith; on the left the closely associated rachis (P) with several xylem bundles may represent a petiole of the same plant (SAR24B4L13);B, Cordaites leaves associated with Pecopteris pinnules;the broadest leaf (CC) with interfascicular scleren-