ephedroids from the Early Cretaceous Yixian Formation in Liaoning ...

246 C. Rydin et al.: Cretaceous ephedroids from China
rounded, elliptic, 2.5–3.5 mm long, 1.2–2 mm
wide.
Etymology. From the robust morphology
of the plant.
Holotype. PB20719. (Figs. 16, 18).
Paratype. (Counterpart) PB20720. (Fig. 17).
Locality. Huangbanjigou Section, Beipiao,
Liaoning, China.
Stratigraphic position and age. Jianshangou
Bed, Yixian Formation, Early Cretaceous
(Barremian-early Aptian?).
Description and comments. The type material
of Liaoxia robusta comprises two compression
fossils of an ephedroid, female plant,
part and counterpart, with oxidized organic
material preserved. The shoot is 17 cm long
(Fig. 16), but on the counterpart, only the
uppermost 8 cm are preserved (Fig. 17). No
internal or external anatomical details are
preserved. Precipitations surround the plant
remains and make stems and leaves appear
wider than they are.
Stems are erect with nodes and internodes,
1.5–2 mm thick, thicker at nodes, and have
longitudinal striations-ridges. Phyllotaxis is
opposite and decussate with multiple axillary
units. Leaves are linear, 15–20 mm long and
appear 1.5–2 mm wide, but the width also
comprises precipitates and the leaves were
probably only 0.5–1 mm wide. Indistinct
remains of three or four veins are present on
some leaves. The plant has about 15 ovulate
cones that are rounded to ellipsoid in longitudinal
outline. Cones vary in length between 7
and 16 mm, but are all about 6–8 mm wide,
sessile or pedunculate, and are positioned
axillary at nodes or terminally on branches.
Cones comprise between approximately 4 and
10 pairs of reflexed and decussately arranged
bracts. The bracts are ovate, 4–7 mm long,
with a long and acute to attenuate apex. Seeds
are rounded to elliptic, 2.5–3.5 mm long and
1.2–2 mm wide, but no cell structures or other
anatomical details are preserved. There is one
seed in the axil of all cone bracts, including
proximal bracts.
This plant differs from other species of
Liaoxia in that all features are larger. Further,
it has multiple axillary branching, which has
otherwise only been observed for Liaoxia
elongata and L. longibractea, and these species
are clearly different from L. robusta in the
characters of the cones. Liaoxia robusta differs
from Ephedra in the presence of seeds in the
axil of all bracts, not only in distal pairs as in
extant Ephedra.
A detached winged seed occurs in close
association with Liaoxia robusta (Fig. 18).
The seed body of this isolated seed is of
approximately the same length as the in situ
seeds and the possibility that it originates
from a Liaoxia cone cannot be ruled out, but
the shape of the seed and the nature of the
wing suggest that it was more likely produced
by one of the conifers reported for the Yixian
Formation.
Liaoxia longibractea Rydin, S.Q. Wu et Friis
sp. nov.
Specific diagnosis. As for the genus with the
following distinctions. Branches c. 1.5 mm
wide, with multiple axillary branching. Cones
sessile to very shortly pedunculate, rounded,
3.5–4 mm long ()15 mm including bract
apex), c. 2–3 mm wide, with 1–2 pairs of
bracts. Cone bracts reflexed, 10–15 mm long,
extended with a setose apex, two parallel
veins. Seeds elliptic, 2.5–4.0 mm long, c.
1 mm wide.
Etymology. Named after the very long and
narrowly extended cone bracts.
Holotype. PB20725 (Fig. 19).
Paratype. PB20726 (the counterpart,
Fig. 20).
Locality. Fanzhangzi Section, Lingyuan,
Liaoning, China.
Stratigraphic position and age. Dawangzhangzi
Bed, Yixian Formation, Early
Cretaceous (Barremian-early Aptian?).
Description and comments. The type material
of Liaoxia longibractea comprises two
relatively well-preserved compression fossils
(part and counterpart) with small amounts of
oxidized organic material preserved. No internal
or external anatomical details are pre-