Pagiophyllum sp.

Halamski, Adam T., 2013, Latest Cretaceous leaf floras from southern Poland and western Ukraine, Acta Palaeontologica Polonica 58 (2), pp. 407-443 : 416-418

Pagiophyllum sp.

Fig. 5G.

Material.—A single fragmentary twig L PB−K.90 from Nemyriv borehole, depth 58 m; (upper?) Campanian.

Description.—The twig fragment is unbranched, 15 mm long and 5 mm wide. Leaves persistent, spirally arranged. Free leaf portions spreading under angles about 30–45 °, 3.5–5 mm long and up to 2.5 mm wide. Three distinct keels present on abaxial surfaces, one median and two near the margins; adaxial side concave, curving towards the axis.

Remarks.—The described fragment is quite similar to Pagiophyllum sp. represented by the single specimen RGM 21188 from the Vaals Formation (lower Campanian) of Vaalsbroek (Limburg, Netherlands) described by van der Ham and van Konijnenburg−van Cittert (2004: fig. 12) in the spiral arrangement and form of leaves (permitting to infer a probable taxodiaceous affinity) as well as the presence of keels on their

http://dx.doi.org/10.4202/app.2011.0024

lower surfaces. The specimens differ in the density of leaves which is lower in the one described here.

Subinfradivision Angiospermae Brown and Doell ex Doell, 1857 (= Magnoliophytina Cronquist, Takhtajan, and Zimmermann, 1966)

Class Dicotyledoneae de Candolle, 1819 (= Magnoliopsida Brongniart, 1843)

Remarks.—As discussed elsewhere ( Halamski 2010), the heterogeneous class Dicotyledoneae may be maintained for practical reasons. Although no unequivocal attribution to a natural taxon can be given for any of the studied leaves, some of them are tentatively arranged according to the natural system after proposed affinities. Remaining leaves are arranged according to an artificial (morphographic) system ( Krassilov 1979; Crabtree 1987) and those too poorly preserved or otherwise unclassifiable are referred to Dicotylophyllum auct. (for the reasons why Dicotylophyllum de Saporta, 1894 may not be used for that effect, see below). Leaf descriptions are standardised after Ellis et al. (2009) with following minor additions and corrections: pedate leaves are considered an organisation type separate from palmate ones; the hyphodromous venation ( Hickey 1973: 26; Dilcher 1974: 32) is considered a separate organisation model; the description of blade characters follows the ontogenetic pattern (therefore “increasing distally” and not “decreasing proximally”); moreover, the term “quinternary” has been replaced by a linguistically more correct “quinquenary” (Latin quinquenarius, fivefold).