in Jurassic and Cretaceous Stratigraphy

Earth Science Frontiers, Vol. 17, Special Issue, Aug. 2010 ISSN 1005-2321
Fossils of Elatides from the Lower Cretaceous Bantou Formation,
Fujian Province, Southeast China
180
Jing Ding 1 , Bainian Sun 1 , Yongdong Wang 2 , Suting Ding 1
1. Key Laboratory of Western China’s Environmental Systems of the Ministry of Education and College of Earth and Environmental
Science, Lanzhou University, Lanzhou 730000, China
2. State Key Laboratory of Palaeobiology and Stratigraphy (Nanjing Institute of Geology and Palaeontology, Chinese Academy of
Sciences), Nanjing 210008, China
The Bantou Formation developed in Yong’an
Basin, Fujian Province, southeast China, which consists
mainly of white, gray and brownish shales and sand-
stones. It is overlain by the red-beds mostly of sand-
stones and rests on a volcanic lava flow known as red
rhyolite. Abundant fossil remains were discovered from
the Bantou Formation (Sze, 1945). According to the
fossil assembles and stratigraphic correlation, an Early
Cretaceous age is supported for the Formation (Sze,
1945). Jishan section, the typical section of the Bantou
Formation, is well exposed in the Jishan village,
southwest Yong’an City. In Feb. of 2009, we collected
many fossils from the Jishan section, including Cup-
ressinocladus elegans Chow, Sphenolepis sp., Pagio-
phyllum gracile Sze, Brachyphyllum obesum Heer,
Elatides sp., Ptilophyllum boreale (Heer) Sewerd,
Zamiophyllum sp. and Cladophlebis browniana (Dun-
ker) Seward and so on. In addition to the plant fossils,
several fish remains have also been found. Here, some
leafy shoots and cones of a conifer fossil Elatides sp. is
described. The extinct genus Elatides is known from the
Middle Jurassic of Yorkshire (Harris, 1943) and from
the Lower Cretaceous of Liaoning, China (Zhou, 1987).
Vegetative organs: Vegetative branches of at least
two orders (incomplete). Ultimate branches 0.4 to 1.2
mm wide, probably oriented in one plane. Leaves
helically arranged. In some cases, leaves are adpressed
to the axis for about half their length and then curve
outward at angles of 40° to 80° (most commonly
50°-60°). Leaves are opposite and whorled on the
lateral shoot, and the successional pair often forms a
right angle with the former pair (Fig.1 1). Although the
leaves are helically arranged, they spread as two lateral
ranks in one plane by twisting at the base. The free part
of the leaves is straight or slightly falcate, more details
of leaves are not visible because of the preservation.
Pollen cones: Young cones are found attached to
leafy shoots (Fig.1 2, 3). They are not well preserved,
appearing to be rounded to elliptical. Elongated cones
of mature or near mature stages are mostly preserved as
detached organs (Fig.1 4, 6). The mature pollen cone is
up to 7 mm long and 2.1-4.5 mm wide, with acute apex.
The microsporophylls occur in a minimum number of
16, they are helically arranged on a 0.6-1.0 mm thick
axis and emerge at right angles. The microsporophylls
head expands nearly horizontally, with acute apex.
Near the base of the microsporophyll head, pollen sacs
are borne abaxially.
Ovulate cones: They are preserved as detached
organs. Megasporangiate cones are elliptical, 10 mm
long and 3.0-5.5 mm wide. Bract-scale complexes are
helically borne on a stout axis up to 1.5 mm in diameter
(Fig.1 5, 7). The bracts are composed of a stalk-like
basal portion and an expanded flattened head with an
acute apex. The basal stalk is perpendicular to the cone
axis on the basal complexes, while the bracts near the
cone apex are inserted in an acute angle. The bract head
is rhomboidal in outline (Fig.1 8), up to 3.2 mm long
and 1.7 mm wide. The abaxial surface of the bracts
shows a distinctive keel. Normally one, rarely two, oval
inverted ovules occur on the proximal part of the
adaxial bract surface (Fig.1 7).
Escapa et al. (2008) assigned a new genus of
Austrohamia (Cupressaceae) from the Jurassic of
Patagonia. The new genus shows similarity to Elatides
morphologically. However, the evolutionary history of
the genus Elatides was not well known for paleo-
botanists. Only williamsonii and Elatides harrisii were
well studied by other authors (Zhou, 1987; Kurmann,
2003). The present fossils are available to reconstruct
the genus. Unfortunately, the specimens are preserved
detached and it is difficult to identify a specific name at
present. However, a further detailed study will be done
for the fossils since the morphological and evolutionary
significance for the extinct Elatides.
Acknowledgements: This research was supported
by the National Basic Research Program of China (No.
2006CB701401), the National Natural Science
Foundation of China (40772012, 40802008) and the
Foundation of the State Key Laboratory of Paleo-
biology and Stratigraphy, Nanjing Institute of Geology
and Paleontology, Chinese Academy of Sciences
(063101, 093110). This is a contribution to IGCP 507.
Key words: Elatides; Lower Cretaceous; Mor-
phology; Fujian Province
References:
Escapa I., Cúneo R., Axsmith B. A new genus of the
Cupressaceae (sensu lato) from the Jurassic of
Patagonia: Implications for conifer megasporan-