Early angiosperms from the Lower Cretaceous of Jixi, eastern ...

Discussion: The present species is characterized by
irregular venation mentioned above.
Material: 2 specimens, including one questionable
in identi¢cation.
Locality and Horizon: Ibid., in the W-B section
bed No.47.
Genus Zhengia Sun et Dilcher gen.nov.
Type: Zhengia chinensis Sun et Dilcher gen.et sp.
nov.
Generic diagnosis: Leaf or lea£et.Margin entire.
Venation pinnate.Secondary veins branching dichotomously
one or two times after going 1/2 distance
to leaf margin.Tertiary and quaternary
veins present.Marginal vein present.Leaves hypostomatic.Stomata
anomocytic; guard cells
sunken; subsidiary cells with collar £ange.
Zhengia chinensis Sun et Dilcher gen. et sp. nov.
Plate IV, 1^7
Synonyms:
1992a Shenkuoa caloneura Sun et Guo; Sun et al., p. 547
pro parte, pl.I, ¢g.14; pl.II, ¢gs.2^6; (non pl.I,
¢g.13; pl.II, ¢g.1).
1996 Zhengia chinensis Sun et Dilcher, p.393, pl.1, ¢g.15;
pl.2, ¢gs.7^9 [nomen nudum, nomen invalidum].
Description: Leaf or lea£et more or less coriaceous,
about 3.5 cm long by 2.4 cm wide; elliptic.
Margin entire.Midvein nearly straight, about 0.5
mm in thickness.Secondary veins arising from
midvein at angles of 60^70‡, and branching dichotomously
one or two times after going 1/2 distance
to the leaf margin.Tertiary and quaternary
veins forming areoles and joining at marginal
vein.Leaves hypostomatic.In upper cuticle, ordinary
epidermal cells irregularly polygonal in form
(average size ca.15U10 Wm), anticlinal walls
nearly straight or slightly sinuous.In lower cu-
Plate III.
G. Sun, D.L. Dilcher / Review of Palaeobotany and Palynology 121 (2002) 91^112 103
ticle, stomata elliptic to ovate, anomocytic (average
size ca.30U25 Wm), randomly orientated.
Guard cell sunken and subsidiary cells cutinized
strongly at edges as a collar £ange.Ordinary epidermal
cells irregularly polygonal in form (average
size ca.25 U20 Wm), outer side of periclinal
walls not smooth, but with numerous grooves.
Holotype: SC10023, Plate IV, 1, 3^6.
Etymology: Zhengia, named in honor of Professor
S.L. Zheng of the Shenyang Institute of Geology
and Mineral Resources for his contributions in
the collecting and research work on the Jixi early
angiosperms; chinensis, country in which the
specimen was discovered.
Discussion: The present species is characterized by
coriaceous leaves, and anatomical features mentioned
above.The present material is similar to
Shenkuoa caloneura, but di¡ers in the secondary
veins branching only one or two times, lacking
exmedial looping near the leaf margin, and a presence
of marginal veins.
Material: 6 specimens.
Locality and horizon: Ibid., in the W-B section
bed No.47.
Genus Xingxuephyllum Sun et Dilcher gen. nov.
Type: Xingxuephyllum jixiense Sun et Dilcher gen.
et sp.nov.
Generic diagnosis: Leaf simple.Margin entire.
Midvein prominent.Venation pinnate.Secondary
veins alternate, branching 1/2 to 2/3 distance to
leaf margin.Tertiary and smaller veins present.
Intramarginal vein present.
Xingxuephyllum jixiense Sun et Dilcher gen. et sp.
nov.
Plate V, 1B, 2; Plate III, ?11; Fig.4G
Description: Leaf simple, about 3.5 cm long by
2.0 cm wide (incomplete preservation). Margin
1^3. Shenkuoa caloneura Sun et Guo emend.Sun et Dilcher.3.Showing the irregular venations.PB16777.1.Bar = 0.5 cm.
2.Bar = 0.3 cm.3.Bar = 1 mm.
4, 5. Reproductive organ A, SC10017.4.Bar = 0.33 cm.5.Bar = 1 cm.
6, 7. Reproductive organ B, SC10018.6.Bar = 0.5 cm.7.Bar = 0.33 cm.
8^10. Asiatifolium elegans Sun, Guo et Zheng emend.Sun et Dilcher, SC10019-10021.Bars = 0.5 cm.
11. Shenkuoa caloneura Sun et Guo emend.Sun et Dilcher, SC10022.Bar = 0.5 cm.