Arthropitys cf. renaultii Boureau, 1964

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 : 50

Arthropitys cf. renaultii Boureau, 1964

( Fig. 4A, E )

This small stem, about 3 mm in diameter, shows an excellent preservation of the tissues. There are 17 primary xylem strands, with circular carinal canals, surrounding the pith (see detail on Figure 4E ). The absence of any secondary xylem supports its interpretation as a very young twig. Other examples of similar small stems have been found with leaves attached. These stems are referred with some reservations, to A. renaultii Boureau, 1964 from the Lower Permian of Autun that represents a similar young stem devoid of secondary xylem, but with a larger number (34) of primary xylem strands and with a proportionally narrower cortex. In the present specimen the outer cortex is sclerenchymatous with alternating parenchyma (arrow, Fig. 4E ) but the inner cortex shows larger cells (C, Fig. 4E ).

Figures

FIG. 4. — Silicified plants from the Permian of Sardinia: A, E, Arthropitys cf. renaultii Boureau; A, transverse section of a young twig (SAR01B1B01); E, detail of the same showing the pith, primary xylem strands with carinal canals and well preserved cortex with large cells (C) in inner cortex and alternating bands of sclerenchyma and parenchyma in outer cortex (arrow); B-D, F, G, Arthropitys bistriata