Ptilozamites sp.

Pott, Christian, 2014, The Upper Triassic flora of Svalbard, Acta Palaeontologica Polonica 59 (3), pp. 709-740 : 724

Ptilozamites sp. cf. Ptilozamites nilssonii Nathorst, 1878a

Fig. 6B.

1983 Ptilozamites sp. ; Vasilevskaya 1983: 144, pl. 1: 2.

Material.— Hopen: Husdalen (? VSEGEI 2/12163); Carnian Upper Triassic).

Description.— The specimen photographed (Fig. 6 B 1) is lacking the lowermost part compared to the figure of Vasilevskaya (1983); it consists of a bifurcate segmented frond, 85.3 mm long. Leaflets are arched towards the frond apex, tongue-shaped with an acutely rounded apex, 18–20 mm long and basally up to 4–6 mm wide, densely spaced and inserted laterally at 35–40° to the rachis on both sides, even after the bifurcation. Leaflets have up to six parallel veins

Fig. 6 B 2). The rachis is less than 2 mm thick and densely striate longitudinally. The angle of bifurcation is 30°.

Remarks.— Vasilevskaya (1983) briefly mentioned this specimen and figured it on plate 1. She described it deriving from Upper Triassic debris close to Hopen Radio in the southern part of the island (here called Husdalen). She questioned the Carnian age of this specimen, since the oldest Ptilozamites specimens were Rhaetian in age. However, records from older sediments have been published recently (Kustatsch- er and Van Konijnenburg-van Cittert 2007) and Hopen is considered to be consisting of entirely Carnian and Norian rocks ( Smith et al. 1975; Mørk et al. 1999; Strullu-Derrien et al. 2012). The specimen from Hopen can be assigned with confidence to the Carnian since it is co-preserved with Pterophyllum filicoides , a typical Carnian index fossil. The specimens match quite well with those of Ptilozamites nilssonii from the Rhaetian of Bjuv in Scania, southern Sweden ( CP personal observation, May 2012; cf. also Kustatscher and Van Konijnenburg-van Cittert 2007). Unfortunately, the Hopen specimen does not provide any cuticle, which would be very useful for comparison. The discovery of Ptilozamites in Carnian strata of Svalbard confirms the older age range of the genus that was formerly deemed to be restricted to the Rhaeto-Liassic ( Kustatscher and Van Konijnenburg-van Cittert 2007); the new record also extends the distribution of the genus northwards. The records from the Anisian–Carnian of the southern Alps require careful re-evaluation since the macromorphology of those leaves is distinct from typical Ptilozamites foliage, and one of those species has recently being transferred to the bennettitalean Anomozamites triangularis based on epidermal anatomy ( Pott and McLoughlin 2009).

Geographic and stratigraphic range.— Europe, Middle East; Ladinian–Lower Jurassic.