The ferns of the late Ladinian, Middle Triassic flora from Monte Agnello, Dolomites, Italy
Kustatscher, Evelyn
Dellantonio, Elio
Van Konijnenburg-Van Cittert, Johanna H. A.
Acta Palaeontologica Polonica
2014
2012-10-23
59
3
741
755
[98,312,854,882]
Polypodiopsida
Osmundaceae
Cladophlebis
Plantae
Osmundales
11
752
Tracheophyta
species
undetermined
Fig. 6B–E. Material.—MGP 63/71, 194/87, 194/88, 194/89A–B, Monte Agnello, Dolomites, N-Italy, early late Ladinian. Description.—The fronds are at least bipinnate. The fragments are up to 80 mmlong and 55 mmwide (MGP 194/88; Fig. 6B). The primary rachis is 3–5 mmthick. Pinnae arise suboppositely and at an acute angle (45–50°) from the rachis, but then curve slightly outwards. Pinnae fragments are up to 55 mmlong and generally 10–12 mmwide; just in one case the pinnae fragments are broader (MGP 194/89A; Fig. 6E). It could belong to a basal frond fragment. The rachis of the pinnae is 1–1.5 mmwide. The pinnules are lanceolate to slightly falcate with a rounded apex and a broad base. The pinnules are densely inserted alternately to suboppositely at an angle of 70–80°. The pinnules are 5–11 mmlong and 2.5–4 mmwide (MGP 194/87; Fig. 6C). The midrib is distinct. The secondary veins arise at an acute angle (c. 50°), bifurcate once halfway along the lamina and perhaps once again near the margin (MGP 63/71; Fig. 6D). Remarks.—These remains are very fragmentary and too badly preserved to be assigned to a new or established species. They resemble the Late Triassic species Cladophlebis remota(Presl, 1838) VanKonijnenburg-van Cittert, Van Konijnenburg-van Cittert, Kustatscher, and Wachtler, 2006, but in the latter species the pinnules are more closely inserted and the apex is acute. Cladophlebis nebbensisBrongniart, 1828) Nathorst, 1876, a typical Rhaeto-Liassic species from Europe and Asia is similar in its once forked secondary veins and slightly restricted pinnule bases, but the pinnules dimensions in C. nebbensisare larger (around 15 mmlong) and the rachis is relatively thin ( Schweitzer et al. 1997).