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

244 C. Rydin et al.: Cretaceous ephedroids from China
about 1.7–2.7 mm wide. Cones are sessile and
placed axillary at nodes or terminally on
branches. Each cone has between 6 and 12
pairs of erect to slightly reflexed bracts that
appear decussately arranged (Fig. 10). Bracts
are narrow and ovate, 1.5–2.0 mm long, with
an acute apex. Seeds or microsporangiate
organs have not been observed.
This fossil is similar to Liaoxia chenii in
vegetative morphology, but the cones are more
elongate in shape. Liaoxia acutiformis is further
distinguished from L. chenii by having a higher
number of bracts, probably up to 12 pairs, in
each cone, in contrast to L. chenii that has 2–6
pairs in each cone. The apex of the cone bracts
differs in being acute to obtuse in L. acutiformis
while it is acute to attenuate in L. chenii.
Liaoxia elongata Rydin, S.Q. Wu et Friis sp.
nov.
Specific diagnosis. As for the genus with the
following distinctions. Branches 0.4–1.5 mm
thick, sometimes with multiple axillary nodes.
Leaves absent. Cones narrowly elongate, 5–
10 mm long, c. 2–3 mm wide, with 8–12 pairs
of bracts. Cone bracts erect, 2.5–4 mm long,
with an attenuate apex.
Etymology. Named after the narrowly
elongated cones.
Holotype. PB20724 (Figs. 14–15).
Paratype. PB20723 (Figs. 12–13).
Locality. Fanzhangzi Section, Lingyuan,
Liaoning, China.
Stratigraphic position and age. Dawangzhangzi
Bed, Yixian Formation, Early
Cretaceous (Barremian-early Aptian?).
Description and comments. The holotype of
Liaoxia elongata comprises the uppermost
5.5 cm of the plant (Figs. 14–15). An additional
specimen is a shoot with slightly larger
structures, c. 4 cm long and 4 cm wide, repre-
senting the central part of the plant (Figs. 12–
13). No anatomical details are preserved.
The stems are erect with nodes and internodes.
Branching is opposite and the paratype
has multiple axillary units (Fig. 12). Stems are
0.4–1.5 mm thick, thicker towards the base
and at nodes, and have very weak remnants of
longitudinal striations. Leaves are absent.
Cones are axillary at nodes or terminally on
branches and may be sessile or pedunculate.
They are narrowly elongate (Figs. 13–14) and
vary in length between 5–6 mm in the holotype
to 6–10 mm in the paratype, but are all
2–3 mm wide. One cone on the paratype is
smaller and rounded, c. 3 · 3 mm (arrow in
Fig. 12). Each cone comprises 8–12 pairs of
erect and decussately arranged bracts. The
bracts are probably very narrowly ovate, c.
2.5–4 mm long, with attenuate apex. Seeds or
microsporangiate organs have not been
observed.
These plants are similar to Liaoxia changii
(Cao et al. 1998) in the over all ephedroid
habit, and the leaf-less stems, but differ from
Liaoxia changii mainly in that they have
cones with more bracts, which are erect and
have a distinctly pointed, attenuate apex. The
cone bracts of Liaoxia changii are slightly
reflexed and have a less distinctly pointed,
acute apex.
Liaoxia robusta Rydin, S.Q. Wu et Friis sp.
nov.
Specific diagnosis. As for the genus with the
following distinctions. Branches 1.5–2 mm
thick, with multiple axillary units. Leaves at
least 15–20 mm long, 0.5–1.0 mm wide. Cones
obovate to elongate 7–16 mm long, c. 6–8 mm
wide, with 4–10 pairs of bracts. Cone bracts
reflexed, 4–7 mm long, ovate with acute to
attenuate apex, one-two parallel veins. Seeds
c
Figs. 1–4. Liaoxia chenii Cao et S.Q. Wu (emend. Rydin, S.Q. Wu et Friis). 1 The holotype of Liaoxia chenii
(PB17800). 2 New specimen (PB20718); the detached apical part of a reproductive shoot. 3–4 New specimen
(PB20717); the uppermost part of a branched plant. Note the seed and the thin leaf indicated by arrows in
Fig. 3. Scale bars = 1 cm in Figs. 1, 2, 4; 0.3 cm in Fig. 3. S = seed; L =leaf