Thuites alienus STERNBERG

Greguš, Josef & Kvaček, Jiří, 2015, Revision Of Cenomanian Flora From The Maletín Sandstone, Acta Musei Nationalis Pragae Series B 71 (3 - 4), pp. 315-364 : 323-324

Thuites alienus STERNBERG

Pl. 5, Fig. 3; Pl. 6, Fig. 1–4; Pl. 7, Fig. 1–8

1825 Thuites alienus STERNBERG , vol. I, 4, p. 40, 38, pl. 45, fig. 1.

1828 Juniperites aliena (STERNBERG) BRONGNIART , p. 108.

1833 Caulerpites fastigiatus STERNBERG , vol. II, 5/6, p. 23, nom. illegit.

1847 Widdringtonites fastigiatus (STERNBERG) ENDLICHER , p. 272, nom. illegit.

1869 Sequoia fastigiata (STERNBERG) HEER , p. 11, pl. 1, fig. 10–13, nom. illegit.

1869 Sequoia reichenbachii (GEINITZ) HEER , p. 7, pl. 1, fig. 1–9.

1971 Sequoia aliena (STERNBERG) KNOBLOCH , p. 44.

L e c t o t y p e: NM-F3675, Pl. 5, Fig. 3, designated here

(Sternberg 1825, pl. 45, fig. 1).

T y p e l o c a l i t y: Smečno (“Smetschna”).

T y p e h o r i z o n: Turonian, Upper Cretaceous.

M a t e r i a l s t u d i e d: GBA_24, 58, 74; GPIT/PL_ 642, 645, 646, 650, 661, 716, 723a,c723b, 725, 737, 751; MMT(M)/G_320, 321, 351, 376, 429, 432, 433, 444, 445, 453, 447; MMT(Z)/G_447; MZM/118_35, 47; NHMW_6; NM-F344; SMNS/650_16; UGV_24.

O c c u r r e n c e: Maletín.

E m e n d e d d i a g n o s i s. Shoot helically covered with leaf cushions of rhombic shape with apparent groove in the middle. Leaf cushions bearing slightly protruding, accuminate, imbricate needles.

D e s c r i p t i o n. The lectotype ( NM-F3675 , Pl. 5, Fig. 3) originally described by Sternberg (1825, p. 38, pl. 45, fig. 1) as Thuites alienus STERNBERG is a 125 mm long fragment of a shoot, with four alternately arranged secondary branches (up to 70 mm), departing in an acute angle. The main shoot is 4–5 mm wide, the secondary branch is 2–3 mm wide. Secondary branches are covered with helically arranged rhombic depressions, which are interpreted as leaf cushions. Rhombic depressions have a groove in the middle, interpreted here as a keel. Imbricate needles (7 mm long) which are acute in the terminal part grow out from leaf cushions. The second specimen from the locality of Smečno ( NM-F344 , Pl. 6, Fig. 1), which comes from the type collection, shows two shoots. Left shoot is 50 mm long, bearing shorter secondary shoots, all covered with helically arranged needles, 7 mm long .

The material from the locality of Maletín is represented by approximately thirty sterile shoots. They are simple, once or several times branched, usually 2–5 mm (up to 7 mm) wide. Main branches are on average 100 mm long (GPIT/ PL_737, Pl. 6, Fig. 4). Narrower branches are covered with helically arranged slightly protruding rhombic scale-like needles, 4–5 mm (up to 7 mm) long, sigmoid and acute in the terminal part. In wider branches, there are apparent leaf cushions (2× 2 mm), sometimes with longitudinal groove. Specimen no. GPIT/PL_650 (Pl. 6, Fig. 2) shows well-preserved wider shoots with leaf cushions and narrower shoots, with scale-like needles.

We assign to this species branches bearing ovuliferous cones, which may not be quite correct, because Thuites alienus is typified by only sterile branches. Fertile specimens (GPIT/PL_716, Pl. 7, Fig. 1; GPIT/PL_725, Pl. 7, Fig. 2; UGV_24, Pl. 7, Fig. 3) are represented by 30–75 mm long branches bearing ovuliferous cones in their terminal parts. These shoots are helically covered with rhombic leaf cushions (2× 2 mm), each with a longitudinal groove. Ovuliferous cones are ovate to shortly cylindrical (10× 16 mm, 16× 26 mm and 18× 27 mm), and singly borne in terminal parts of shoots. Two cones (GPIT/PL_725; UGV_24) are preserved in the rock as longitudinally fractured fragments. Their axes are 1–2 mm long, consisting of helically arranged peltate cone scales. Specimen no. GPIT/PL_716 shows a complete terminally borne ovuliferous cone, with rhombic-shaped scales on its surface (5–6 mm wide and 3–4 mm high), with poorly preserved longitudinal groove. In some specimens (GPIT/PL_723a, Pl. 7, Fig. 4; SMNS/650_16, Pl. 7, Fig. 6; MMT(Z)/G_447, Pl. 7, Fig. 7; NHMW_6, Pl. 7, Fig. 8), there are similar ovuliferous cones borne on shoots. The ovuliferous cone GPIT/PL_723b (Pl. 7, Fig. 5) is preserved in the rock as transversally broken, showing pelate cone scales.

R e m a r k s o n n o m e n c l a t u r e. From the type collection of Kaspar Sternberg, we have chosen the lectotype ( NM-F3675 ) figured by Sternberg (1825, pl. 45, fig. 1). The Sternberg type collection is recognized by old evidence numbers, which were written by František Xaver Maximilian Zippe. The type specimens, which were found in collections of the National Museum, have original numbers 353 (Sternberg 1825, pl. 45, fig. 1, NM-F3675 ) and 355 ( NM-F344 ), respectively .

D i s c u s s i o n. The closest taxon to Thuites alienus is a fossil species Geinitzia reichenbachii (GEINITZ) HOLLICK et JEFFREY , described from the locality of Hudcov (Hundorf) from the Teplice Formation (Turonian) of the Bohemian Cretaceous Basin ( Kunzmann 2010, Geinitz 1842). G reichenbachii has falcate needles ( Hollick and Jeffrey 1909), in contrary to T. alienus . T. gramineus , described by Sternberg (1825) from the Peruc locality (Cenomanian) was assigned by Knobloch (1971) to the genus Widringtonia ( Widringtonia graminea (STERNBERG) KNOBLOCH). Other Sternberg species, such as T. cupressiformis , T. articulatus , T. expansus and T. divaricatus (described from the British Jurassic, locality Stonesfield) were removed in the first half of 20 th century to Brachyphyllum i. e. B. expansum (STERNBERG) SEWARD ( Cleal and Rees 2003). Fertile specimens of ovuliferous cones attached to branches, and simple ovuliferous cones are assigned to the species with a question mark as cf. Thuites alienus , because T. alienus is defined by sterile axes. We prefer to identify sole, poorly preserved ovuliferous cones the genus Conago .