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ACTA GEOLOGIA SINICA Vol.78 No.4 2004
Early Cretaceous Archaefructus eoflora sp. nov. with Bisexual Flowers from
Beipiao, Western Liaoning, China
JI Qiang, LI Hongqi, L.Michelle BOWE, LIU Yusheng and David Winship TAYLOR
Recently, whether Archaefructus has bisexual multi-parted flowers or just
inflorescences of unisexual flowers, and whether it is ancestral to all
angiosperms or a derived eudicot have been debated. Here, from the same Yixian
Formation, NE China, we report a new Archaefructus species, A. eoflora sp.
nov., with the generic characteristics of dissected leaves and bisexual
reproductive axes. It is entirely preserved with roots, rhizome, shoots and
protogynous reproductive organs at different developmental stages. Its lateral
and main fertile shoots form a pseudo-indeterminate pattern, while the
reproductive branches on the main shoot form a cymose inflorescence. Subtended
by 1-2 bract-like leaves, the section of stamen clusters changes into a much
shorter section of carpels that have one row of orthotropous ovules.
Significantly, one cluster bearing two carpels and one stamen between the two
sections demonstrates a true bisexual flower, an important step of the origin
of floral !
bisexuality, and the homology between the stamen and carpel. The complex
reproductive axes represent a mix between flowers and inflorescences, and
suggest that A. eoflora sp. nov. possesses the potential to evolve into a
variety of diverse flower types as found in modern basal and early fossil
angiosperms. A comparison with other two species also leads to a revision of
the generic diagnosis.
Postcranial Anatomy of the Mesozoic Dalinghosaurus (Squamata): Evidence from a
New Specimen of Western Liaoning
JI Shu’an and JI Qiang
The postcranial skeleton of a new specimen of the long-tailed lizard
Dalinghosaurus longidigitus was excavated from the Yixian Formation in
Lingyuan, western Liaoning. The new specimen provides more anatomical
information about this species, especially about the anterior dorsal vertebrae,
shoulder girdle and forelimbs. This lizard can be included within the clade
Scleroglossa by its 27 or more presacrals, moderately long pubis, and gently
notched distal end of tibia. But the detailed systematic position for this
taxon remains undetermined. The features of the much longer hind limbs and pes
compared with forelimbs and manus, metatarsal IV longer than III, pedal
phalanges robust, and penultimate phalanx not longer than other phalanges etc.
suggest that this lizard was a running and ground swelling animal.
A Titanosaurian Sauropod Dinosaur with Opisthocoelous Caudal Vertebrae from the
Early Late Cretaceous of Liaoning Province, China
YOU Hailu, JI Qiang, Matthew C. LAMANNA, LI Jinglu and LI Yinxian
We describe a new titanosaurian sauropod dinosaur, Borealosaurus wimani gen. et
sp. nov., based on a distinctive mid-distal caudal vertebra from the early Late
Cretaceous Sunjiawan Formation exposed in the Shuangmiao village of Beipiao in
Liaoning, China. We provisionally refer an isolated tooth crown, a middle
caudal verebra, and a right humerus from the same locality and horizon to this
taxon. Borealosaurus is distinguished from other sauropods in its possession of
opisthocoelous mid-distal caudal vertebrae. The occurrence opisthocoelous
caudals in Borealosaurus and the Mongolian sauropod Opisthocoelicaudia raises
the possibility that these taxa pertain to an as-yet unrecognized titanosaurian
subclade endemic to the Cretaceous Asia.
TAKAHASHI, Kazuo 高橋 和男