Neocalamites merianii ( Brongniart,1828b ) Halle, 1908

Pott, Christian, 2014, The Upper Triassic flora of Svalbard, Acta Palaeontologica Polonica 59 (3), pp. 709-740 : 713-714

Neocalamites merianii ( Brongniart,1828b) Halle, 1908

Fig. 2A–I.

1828 Equisetum merianii ; Brongniart 1828b: 115, pl. 12: 13.

1908 Neocalamites merianii (Brongn.) ; Halle 1908: 6.

1926 Equisetaceous stems; Høeg 1926: 33, pl. 9: b3, 4.

1972 Neocalamites merianii (Brongn.) Halle ; Vasilevskaya 1972: 32, pl. 1: 1–3.

1972 Neocalamites cf. merianii (Brongn.) Halle ; Vasilevskaya 1972: 33, pl. 1: 4, 5, 8.

1972 Neocalamites sp. ; Vasilevskaya 1972: 34, pl. 2: 1.

1983 Neocalamites sp. ; Vasilevskaya 1983: 143, pl. 1: 1.

2008 Neocalamites merianii (Brongniart 1828) Halle 1908 ; Pott et al. 2008a: 188, pls. 3: 1–4; 4: 1–5.

Material.— Spitsbergen: Bertilryggen ( NRM S 080244– S 080246, S 080248– S 080251, S 080254, S 080256, S 080258); Fleur de Lyshamna ( NRM S 080071, S 080072, S 080088, S 080105); Wimanfjellet ( VSEGEI 10979-01, 10979-02); Trehøgdene ( NRM S 151678, S 151679); Teistberget ( VSEGEI 10979-03, 10979-07); Amadeusberget ( NRM S 080259, S 080260); Edlundfjellet ( NRM S 080261, S 080262). Edgeøya: Kapp Lee ( NRM S 080202, S 080203, S 080226); Kvalpynten ( NRM S 080243); Kapp Pechuel Lösche/Lindemanberget ( VSEGEI 10979-04–10979-06)]. Hopen: Nørdstefjellet ( NRM S 080264– S 080269); Blåfjell (? VSEGEI 1/12163). Carnian (Upper Triassic).

Description.— Neocalamites merianii occurs at several of the localities as impressions and pith casts of two orders of axes (cf. Pott et al. 2008a). All specimens are incomplete; one of the longest shoot portions is 31.6 cm long (Fig. 2 A); shoots of the first order (primary shoots) are 35–51 mm wide (e.g., Fig. 2 B), those of the second order (lateral branches) are 22–24 mm or 10–13 mm wide in the middle of the internodes (e.g., Fig. 2 B, E), the latter group may represent third order branches (cf. Pott et al. 2008a: text-fig. 3). Lengths of internodes are difficult to measure, since few are complete, but the longest in first order shoots exceed 145 mm in length whereas those of the other two categories are 54–118 mm long. The nodes are slightly wider than the internodes. The outer surface of the internodes is characterised by broad, almost imperceptible longitudinal striae, while the inner surface is marked by densely arranged prominent longitudinal striae (depicting the positions of massive vascular bundles). Microphylls are not preserved attached to any shoots, but two specimens constitute incomplete rings of microphylls that are 2 mm wide and bear a prominent central single bundle (Fig. 2 C, D). The number of microphylls per whorl may reach 65, since the preserved parts show up to 22 microphylls and are interpreted to represent c. one third to one half of the axis’ circumference.

One specimen from Bertilryggen ( NRM S080248 ; Fig. 2 F) is here interpreted as a strobilus of Neocalamites merianii . A slender, 3–4 mm wide axis bears a small terminal strobilus, 42 mm long and 6–8 mm wide, consisting of small 2× 3 mm wide scales (= sporangiophores), regularly arranged around a central axis. All scales bear thin, 2 mm long spines. The host axis bears spines (or leaf remnants) at intervals 7 mm apart (Fig. 2 F).

Remarks.— Neocalamites merianii is a very common element in many Carnian–Rhaetian floras of central Europe and may have grown in large monotypic stands. A thorough revision of the species including the reconstruction of its growth habit and possible ecological requirements has recently been published based on a vast amount of excellently preserved specimens from the Carnian flora of Lunz in Lower Austria ( Pott et al. 2008a). The Svalbard specimens match closely those from Lunz and are here considered conspecific. Vasilevskaya (1972, 1983) treated some of the specimens with caution and refrained from assigning them to N. merianii , but in my point of view, all belong to this species. The fertile specimen strongly resembles strobili assigned to N. aff. carrerei Zeiller, 1903 ) Halle, 1908 by Vladimirovicz (1958) or to N. merianii by Pott et al. (2008a). Additional evidence for this assignment comes from recently discovered Neocalamites specimens from the Upper Triassic of China with attached strobili that match very well in size, but the sporangiophores are smaller, have a different shape and the strobili were assigned to a different species, viz. N. horridus Zan, Axsmith, Escapa, Fraser, Liu, and Xing, 2012 ( Zan et al. 2012).

Geographic and stratigraphic range.— Southern Germany, Switzerland, Austria, Svalbard; Ladinian–Carnian.