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

veins poorly preserved, arising from midrib and
secondary veins at wide angles.Quaternary veins
borne at wide angles (up to 90‡) and transverse
leaf lamina to a marginal vein.The 5th order
reticulate venation preserved.Thick marginal
vein forms part of the leaf margin.
Holotype: SC10014, Plate II, 2, 11.
Discussion: The present species is characterized by
secondary lobes, and the secondary veins arising
opposite or nearly opposite from the midvein
which is the major di¡erence between the present
species and Jixia pinnatipartita.
Material: 12 specimens.
Locality and horizon: Ibid., in the W-B section
beds Nos.45 and 47.
Jixia sp.
Plate II, 4,12;Fig.4H
Synonym:
1995 Angiosperm leaf A, Sun, p.429, text-¢g.9^2, 7.
Description: An isolated lobe, more than 3.0 cm
long by 1.0^1.1 cm wide; alternate and oblique
pinnately lobed.Apex and base not preserved.
Lobes nearly asymmetrically triangular in shape,
bluntly acute in apex.Secondary vein thin and
slightly curved.Tertiary veins alternate and narrow,
arising from secondary vein and reaching
each lobe apex.Quaternary and their smaller
veins form areoles.
Discussion: Morphologically, the present isolated
lobe should be attributed to Jixia.The present
species is more or less similar to Jixia pinnatipartita
morphologically, but di¡ers in having triangular
lobes.The present material is also similar to
Jixia chengzihensis, but di¡ers in having alternate
tertiary veins arising from the secondary vein, and
having triangular lobes.
Plate II.
G. Sun, D.L. Dilcher / Review of Palaeobotany and Palynology 121 (2002) 91^112 101
Material: 3 specimens.
Locality and horizon: Ibid., in the W-B section
bed No.47.
Genus Shenkuoa Sun et Guo, 1992
Type: Shenkuoa caloneura Sun et Guo
Generic diagnosis: Leaf simple; apex acute, margin
entire.Venation pinnate, brochidodromous.
Midvein prominent.Secondary veins subopposite,
more than 8 pairs, branching profusely.Exmedial
loops of secondary veins along leaf margin.Tertiary
and quaternary veins present.Marginal vein
absent.
Shenkuoa caloneura Sun et Guo emend.Sun et
Dilcher
Plate III, 1^3, ?11; Fig.4E
Synonyms:
1992a Shenkuoa caloneura Sun et Guo; Sun et al., p. 547
pro parte, pl.I, ¢g.13; pl.II, ¢g.1; (non pl.I, ¢g.
14, pl.II, ¢gs.2^6).
1995 Shenkuoa caloneura Sun et Guo; Sun, p.429, pl.141,
¢g.6, text-¢g.9^2, 6.
1996 Shenkuoa caloneura Sun et Guo; Sun and Dilcher, p.
393, pl.1, ¢g.6, text-¢g.12^14.
Emended description: Leaf simple; margin entire;
apex bluntly acute.Midvein given rise to secondary
veins which arch upward then away at angles
of 60^70‡.Intersecondary veins present and
branching profusely.Secondary veins forking
broadly ca.70‡ and profusely toward the leaf
margin.Very weakly brochidodromous interconnections
formed between secondary veins.Exmedial
loops of the secondary veins extending to and
along the leaf margin.No regular loops observed.
Tertiary and quaternary veins usually forming
rectangular or pentagonal areoles.No marginal
vein observed.
1, 9. Jixia pinnatipartita Guo et Sun emend.Sun et Dilcher, PB16773.1.Bar = 0.5 cm.9.Bar = 0.5 cm.
2, 11. Jixia chengzihensis Sun et Dilcher sp. nov., Holotype SC10014. 2. Bar = 0.5 cm. 11. Bar = 0.5 cm.
3, 6. Jixia chengzihensis Sun et Dilcher sp. nov., PB16774. 3. Bar = 0.5 cm. 6. Bar = 0.5 cm.
4, 12. Jixia sp., SC10016. 4. Bar = 0.5 cm. 12. Bar = 0.5 cm.
5, 8. Jixia chengzihensis Sun et Dilcher sp. nov., SC10015. 5. Bar = 0.5 cm. 8. Bar = 0.5 cm.
7. Jixia chengzihensis Sun et Dilcher sp. nov., PB16775. Bar = 0.5 cm.
10. Jixia chengzihensis Sun et Dilcher sp. nov., SC10027. Bar = 0.5 cm.
13. Jixia chengzihensis Sun et Dilcher sp. nov., showing sublobes of 3. Bar = 0.5 mm.