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

242 C. Rydin et al.: Cretaceous ephedroids from China
1999 Liaoxia chenii Cao et S.Q. Wu — Wu p.
21, plate XIV:3, XV:3.
2000 Ephedrites chenii (Cao et S.Q. Wu) Guo
et X.W. Wu — Guo and Wu p. 86, plates I:1–
4, II:1–4.
2001 Ephedrites chenii (Cao et S.Q. Wu) Guo
et X.W. Wu — Sun et al. p. 206, plates 24:2,
64:1, 3–6 (non plate 64:7–9).
2003 Liaoxia chenii Cao et S.Q. Wu — Chang,
p. 174, Fig. 241.
Emended specific diagnosis. As for the
genus with the following distinctions. Branches
c. 0.5–3.0 mm wide, internodes 8–40 mm long.
Leaves 5–20 mm long, with two parallel veins.
Cones obovate, 4–10 mm long, 2–5 mm wide,
with 2–6 pairs of bracts. Cone bracts ovate to
triangular and reflexed, c. 4 mm long, with an
acute to attenuate apex, two parallel veins.
Seeds ovoid to elliptic, c. 1 mm long, c. 0.3–
0.7 mm wide.
Holotype. PB17800 (Fig. 1).
Paratype. PB17801.
Type locality. Near Chaomidian at Shangyuan
Village of Beipiao, Liaoning, China.
Stratigraphic position and age. Jianshangou
Bed, Yixian Formation, Early Cretaceous
(Barremian-early Aptian?).
Comments on the type material. The holotype
of Liaoxia chenii (PB17800, Cao et al.
1998) (Fig. 1) is a reproductive shoot, c. 9 cm
long. It is clearly ephedroid in gross-morphology
with striate stems, 1–3 mm wide. Branching
is opposite and decussate with distinct
nodes. Internodes are 8–40 mm long. Leaves
are linear, at least 20 mm long and c. 1–2 mm
wide, probably with two parallel veins. Cones
are 5–10 mm long and 3–4 mm wide, obovate
with 2–6 pairs of reflexed cone bracts, c. 4 mm
long, and ovate with an attenuate apex. Cone
bracts have two parallel veins.
Note that in the description of Ephedrites
chenii in Sun et al. (2001), two additional
specimens (plate 64, Figs. 7–9) are presented.
These fossils may be ephedroid, but they lack
features characterising Liaoxia and are not
included here in the synonymy list of Liaoxia
chenii.
New material of Liaoxia chenii. Specimens
PB20717–PB20718 (Figs. 2–4) from the Huangbanjigou
Section, includes two compression
fossils with oxidized organic material. The
specimens show distinct features of Liaoxia
chenii and are here included in this species. In
one specimen the uppermost 5 cm of a
branched plant, c. 13 cm wide, is preserved
(Figs. 3–4). The other specimen is a detached
apical part of a reproductive shoot, 2.5 cm
long (Fig. 2). Stems are erect with 8–17 mm
long internodes, longitudinally striate and
2 mm wide in basal parts and 0.5 mm in upper
parts, thicker at nodes. Phyllotaxis is opposite
and decussate. Leaves are linear (Figs. 2–3), up
to at least 7 mm long and 0.1–0.3 mm wide.
Venation is indistinct, but there are apparently
two parallel veins in each leaf. Cones are
axillary at nodes or terminating branches,
sessile or pedunculate, and obovate to elongate,
4–7 mm long, 2.5–5 mm wide and with
2–6 pairs of bracts. Cone bracts are delicate
and with two veins (Fig. 3). They are narrowly
ovate with an acute to attenuate apex, 3–4 mm
long, about 0.8 mm wide at the base, 0.3
towards the apex, decussately arranged and
often reflexed to a position almost at a right
angle to the cone axis. A few seeds are
preserved in the axils of apical or distal cones
bracts of some cones (indicated by an arrow in
Fig. 3). They are ovoid and 0.9–1.1 mm long
and 0.3–0.7 mm wide. No internal or external
anatomical details are preserved.
Liaoxia changii (Cao et S.Q. Wu) Rydin,
S.Q. Wu et Friis comb. nov.
Basionym. Eragrosites changii Cao et S.Q.
Wu (Cao et al., February 1998. Chinese Sci.
Bull. 43: p. 231, plate II:1–3).
Synonyms and previously published material.
1999 Liaoxia changii Cao et S.Q. Wu — Wu, p.
21, plate XV:1, 4.
2000 Ephedrites chenii (Cao et S.Q. Wu) Guo
et X.W. Wu — Guo et Wu p. 86, plates 1:5–7
and 2:5–8.