Tetraclinis salicornioides (UNGER) KVAČEK

Kvaček, Zlatko & Teodoridis, Vasilis, 2011, The Late Eocene Flora Of Kučlín Near Bílina In North Bohemia Revisited, Acta Musei Nationalis Pragae Series B 67 (3 - 4), pp. 83-144 : 88

Tetraclinis salicornioides (UNGER) KVAČEK

Pl. 1, figs 17-18

1847 Thuites salicornioides UNGER , p. 11, pl. 2, figs 1-4, pl. 20, fig. 8.

1866 Libocedrus salicornioides ENDL. sp.; Ettingshausen, p. 33, pl. 10, fig. 5 (non fig. 14).

1989 Tetraclinis salicornioides (UNGER) KVAČEK , p. 48, pl. 1, fig. 11, pl. 2, figs 2-14, pl. 3, figs 1-4, text-fig. 1.

1990 Tetraclinis salicornioides (UNGER) KVAČEK ; Bůžek, Fejfar, Konzalová, Kvaček, p. 172, fig. 3.3.

Branches fragmentary, (bi-)pinnately and oppositely branched in flat sprays without overlapping of branches. Branchlets flattened, with four-ranked dimorphic scale leaves borne in pseudo-whorls. Ultimate twigs diverging from each node of penultimate twigs in opposite pinnate arrangement; ultimate twigs often with two ranks of dimorphic scale leaves, dimorphic; facial and lateral leaves with rounded to bluntly mucronate apices, in each pseudo-whorl fused most of their length to form a dorsoventrally flattened phylloclade-like segments, simple pseudo-whorls oval, triveined in surface view or wider, compressed pseudo-whorls at nodes of branching, expanded apically, showing five (to seven) prominent longitudinal lines on the either surface. Apices of the leaves of one node slightly overlapping the leaf bases of the supradjacent node. Facial leaves appressed, ob-triangular, with obvious central midvein; lateral leaves lanceolate to falcate, each folded along its midvein in the plane of compression, shorter than the facial, closely imbricate, more commonly fused to the margins of the facial leaves, base cuneate, apex acute. Seed double winged, seed body ovate, 4 mm long, 2.3 mm wide, wings basally orient- ed, attached laterally, at the seed base rounded, 2.5 mm wide. Seed cones not recorded in the Kučlín material.

D i s c u s s i o n: The cladode-like twigs and seeds of T. salicornioides occur extremely rarely in the Kučlín diatomite. This conifer became more spread only in younger strata of the České středohoří Mountains and was widely distributed in the European Oligocene and Neogene (Kvaček 1989). This conifer is, contrary to its extant and fossil subxerophytic relatives T. verticillata and T. brachyodon , a humid subtropical element avoiding azonal vegetation. Its earliest record was documented in Europe in the Middle Eocene (Eckfeld maar – Wilde and Frankenhäuser 1998, as Libocedrites ) and in North America in the Oligocene ( Kvaček et al. 2000). Its last remnants are known from the Pliocene of Germany, Italy and the Caucasus area ( Mai 1995 – as Tetraclinis brachyodon ).

Impressions of sterile foliage of Tetraclinis salicornioides are almost indistinguishable from a related extinct conifer Ditaxocladus S. X. GUO et Z. H. SUN occurring in the Late Cretaceous and the Paleocene in the Northern Hemisphere (Guo et al. in press). The sprays of both conifers are composed of cladode-like regularly oppositely branched dorsiventrally flattened twigs. The only difference is in the general form of the sprays, which is slender elongate in Ditaxocladus and widely spread in Tetraclinis salicornioides . More pronounced differences are in the seed cones (subglobose in racemose fertile branches in Ditaxocladus vs quadrivalvate solitary or paired in Tetraclinis ) and leaf anatomy (non-papillate straight-walled stomatal zones with thin Florin rings in Ditaxocladus vs thick and papillate cuticles with undulate anticlines in Tetraclinis ).

M a t e r i a l: KUC 402B, NM G 8598, G 8599.

Doliostrobaceae Kvaček (2002b)

The family is comprised of the type-bringing genus Doliostrobus MARION (1888) and two fossil genera Araucariacites KRUTZSCH (type A. europaeus KRUTZSCH 1971 ) for dispersed pollen and Doliostroboxylon DOLEZYCH in Junge et al. (2005) for wood. The latter taxon requires validation (no type designated – ICBN Art. 7.9, 7.11).