Dictyophyllum sp.

Pott, Christian, 2014, The Upper Triassic flora of Svalbard, Acta Palaeontologica Polonica 59 (3), pp. 709-740 : 718

Dictyophyllum sp.

Fig. 4B.

1972 Dictyophyllum sp. 1 ; Vasilevskaya 1972: 38, pl. 5: 1–3a. 1972 Dictyophyllum sp. 2 ; Vasilevskaya1972: 39, pl. 6: 1.

Material.— Spitsbergen: Wimanfjellet ( VSEGEI 10979-08, 10979-29, 10979-30); Carnian (Upper Triassic).

Description.— Three samples from Wimanfjellet yield fragmentary sterile pinnae assignable to Dictyophyllum . The longest pinna fragment is 83 mm long and 23 mm wide; 12 pairs of pinnules are incompletely preserved (Fig. 4 B). Pinnules are 7–8 mm wide basally and up to 12 mm long with perfectly rounded apices. They are characterised by a thin central vein emerging at 70–80° from the midvein and extending to the pinna apex. The complex network of secondary veins typical of Dictyophyllum foliage is barely perceptible due to the poor preservation.

Remarks.— Like Vasilevskaya (1972), I refrain from assigning the isolated pinnae from Wimanfjellet to a formal species owing to their fragmentary state. The pinnae are quite similar to material reported by Yokoyama (1891, 1905) as Dictyophyllum kochibei Yokoyama, 1891 from the Rhaetian shales of Nagato, Japan. They match very well in pinna outline, margin shape and size ranges, however, more details of the venation are known from the Japanese material, whereas these are not visible in the Svalbard specimens. The central vein is straighter in the Svalbard material and marginal pinnae lobes are more rounded than the slightly acute lobes of D. kochibei . Consequently, I refrain from assigning the Svalbard specimens to D. kochibei . The specimens are readily distinguished from D. exile and D. nathorstii by their round (vs. pointed) pinnule apices and the straight (vs. curved) central vein (cf. Schweitzer et al. 2009; Pott and Mcloughlin 2011).