Mihai's Paleobotany Chronicles

Stachyotaxus septentrionalis (AGARDH) ARNDT 2002

1823 Sargassum septentrionale AGARDH, p. 108, Pl. 2, Fig. 8;
1926 Stachyotaxus elegans HARRIS, p. 119-122, Pl. X, figs. 2-4, Pl. XII, figs. 1, 2, 6, Pl. XIII, fig. 5, Text-fig. 30 E, F, I, J;
1935 Stachyotaxus elegans HARRIS, p. 52-55, Pl. 10, figs. 1-3, 6-9, 11, Pl. 21, figs. 1-3, Pl. 27, fig. 7, Text-fig. 23;
1935 Stachyotaxus septentrionalis HARRIS, p. 56-58, Pl. 9, figs. 11, 12, 14-17, Pl. 10, figs. 4, 5, 10, 12, 13;
1937 Stachyotaxus elegans HARRIS, p. 60;
1937 Stachyotaxus septentrionalis HARRIS, p. 60;
1946 Stachyotaxus elegans HARRIS, p. 26;
2002 Stachyotaxus septentrionalis ARNDT, p. 13-15, Text-figs. 5, 6, Pl. 3, Figs. 1-6.


Short description
Trunks, branches, roots, leaves, female cones and seeds and pollen cones were collected. The trunks are large, with wrinkled bark. Shoot axes are covered with spirally inserted leaves that are uninerve, with a constricted basis (Elatocladus-like), elongated leaf cushions, entire margins, and a slightly acute apex. Cuticles are very thin and fragile. Seed cones are cylindrical in outline, long, with spirally arranged bracts that show no separation within the bract-scale complex. The bracts are uninerve, with entire margins, and a sharp apex. They are strongly curved, supporting adaxially two ovules with an elongated micropyle. Pollen cones ares short, usually badly preserved, with microsporophylls inserted spirally.

S. elegans is a junior synonym of S. septentrionalis, as Arndt (2002) demonstrated, the separation between the previous two species being based mainly on size and shape of leaves. The Swedish material shows clearly the lack of any difference between the two species, and the Greenlandic material points to the same conclusion: S. elegans is a junior synonym of S. septentrionalis. Arndt (2002) redescribed the ovulate cones of S. elegans.

In Jameson Land, we could collect S. septentrionalis from Astartekloeft, South Tancredia and Primulaelv. In Astartekloeft, this species is particularly abundant, mainly in Bed 5, known also as the Stachyotaxus Bed of Harris. In Europe, S. septentrionalis was described mainly from Scania.

Late Triassic.

Marsh edges.

The best preserved material was collected from Astartekloeft, from Bed 5 (Harris' Stachyotaxus Bed).

Stachyotaxus septentrionalis, shoot fragment, Stachyotaxus Bed of Harris (Bed 5), Astartekloeft. Scale bar: 10mm.
Stachyotaxus septentrionalis, ovulate cone fragment, Stachyotaxus Bed of Harris (Bed 5), Astartekloeft. Scale bar: 10mm.

Agardh, C.A., 1823. Narmare bestammande af nagra Vextaftryck funne uti Hoganas stenkolsgrufvor.

Arndt, S., 2002. Morphologie und Systematik ausgewahlter Mesozoischer Koniferen. Palaeontographica Abt. B, 262(1-4): 1-23.

Harris, T.M., 1926. The Rhaetic flora of Scoresby Sound, East Greenland. Saertryk af Meddelelser on Gronland, LXVIII.

Harris, T.M., 1935. The fossil flora of Scoresby Sound, East Greenland. Part 4: Ginkgoales, Coniferales, Lycopodiales and isolated fructifications. Meddelelser om Gronland, 112, Kobenhavn, 1-176 pp.

Harris, T.M., 1937. The fossil flora of Scoresby Sound, East Greenland. Part 5: Stratigraphic relations of the plant beds. Meddelelser om Gronland, 112, Kobenhavn, 1-114 pp.

Harris, T.M., 1946. Liassic and Rhaetic plants collected in 1936-1938 from East Greenland. Meddelelser om Gronland, 114, Kobenhavn, 1-36 pp.