Ginkgoalean ovulate organs and seeds associated with Baiera furcata-type leaves from the Middle Jurassic of Qinghai Province, China

Wu, Xiangwu; Yang, Xiaoju; Zhou, Zhiyan

doi:10.1016/j.revpalbo.2006.01.009

Cited by 24 publications

(6 citation statements)

References 7 publications

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“…Other seed ferns such as Ktalenia and Petriellaea have very small ovules. In the present material, no stomata were observed in the integument, while they are quite frequent in other groups such as Ginkgoales (Wu et al 2006); this could be related to the protected position of the structures in cupules.…”

Section: Discussioncontrasting

confidence: 49%

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Structure of corystospermaceous ovules from the Upper Triassic of Zimbabwe

Barale

Guignard

Bamford

2009

Botany

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Isolated ovules from the Upper Triassic of Zimbabwe were observed using three complementary approaches: light microscopy and, for the first time, scanning electron microscopy and transmission electron microscopy. Complete ovules showed a curved bifid micropylar tube. Three envelopes were present: integument, nucellus, and megaspore. The integument appeared resiniferous. The nucellus was made up of bulging cells around the pollen chamber, which contained bisaccate pollen grains. The ultrastructure of the nucellus revealed a lamellar organization in their microsinuosities. The megaspore membrane was made up of agglomerate rounded bodies more or less closely arranged and surrounded by two layers. The material may be attributed to Umkomasiaceae. A comparison with ovules of different related groups (seed ferns, Caytoniales, Ginkgoales, Nilssoniales, and Coniferales) was made. The Umkomasiales are considered to be a more primitive group than the Pteridospermales with regard to integument and nucellus.Résumé : Des ovules isolés du Trias terminal de Zimbabwe ont été observés avec trois approches complémentaires, au microscope photonique et pour la première fois au microscope électronique à balayage et à transmission. Les ovules complets montrent un tube micropylaire bifide recourbé. Trois enveloppes ont pu être étudiées : un tégument, un nucelle et une mé-gaspore. Le tégument semble résinifère. Le nucelle est constitué de cellules bombées autour de la chambre pollinique qui contient des grains de pollen à ballonnets. L'ultrastructure du nucelle révèle une organisation lamellaire dans les microsinuosités. La membrane de la mégaspore est constituée de corps arrondis plus ou moins agglomérés, limitée par deux couches. Le matériel a pu être attribué aux Umkomasiaceae. Une comparaison avec l'organisation des ovules de différents groupes apparentés (fougères à ovules, Caytoniales, Ginkgoales, Nilssoniales et Coniférales) est faite. Les Umkomasiales sont considérés comme représentant un groupe plus primitif que celui des Ptéridospermales sur la base du rapport tégument/nucelle.

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Section: Discussioncontrasting

confidence: 49%

“…In Cycads, the integument and nucellar tissues are indistinguishable below the level of the pollen chamber at all stages of development (Kershaw 1912). In Ginkgoales, Wu et al (2006) describe the ovules of Baiera furcata type from the Middle Jurassic of China. The nucellus is free from the integument nearly to the base of the ovule.…”

Section: Discussionmentioning

confidence: 99%

Structure of corystospermaceous ovules from the Upper Triassic of Zimbabwe

Barale

Guignard

Bamford

2009

Botany

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“…Ginkgoidium nathorsti was distributed during the Late Triassic on the Cañadon Largo and Llantenes de Argentina Formations (Menéndez 1951;Gnaedinger and Herbst 1999), during the Jurassic in Kaga, Hida, Echizen (Yokoyama 1889) and the Itoshiro Group during the Lower Cretaceous in Japan (Kimura and Tsujii 1984), S. mixteca regroups with other two samples from Oaxaca, that differ from S. mixteca differs from S. bifida and S. argentinae on the terminal segments, maximum width, basal angle and the number of veins that are two or three times bigger on the Mexican species (Plate 5(C)). As a final consideration, it is important to mention that the majority of OTUs used on this study are from a Triassic age (Gnaedinger and Herbst 1999;Wu et al 2006;Zhou and Wu 2006); similarly, it has been mentioned that the diversity of this group grew during this period on Asia and Gondwana, but not North America. The Sphenobaiera genus was the most diverse and abundant during the Jurassic Period in Mexico, where the Ginkgoidium could be compared on abundance with worldwide records (Ô ishi 1940; Kimura and Tsujii 1984;Gnaedinger and Herbst 1999).…”

Section: Discussionmentioning

confidence: 99%

Two new species of Ginkgoales from the Middle Jurassic of Mexico

et al. 2014

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This paper reports two new species of Ginkgoales collected from the Cañada Alejandro and Río Ñ umi (Zorrillo and Zorrillo -Taberna Undifferentiated Formations, Middle Jurassic). Thirty-one fossils were selected and compared with 14 species from different localities. A numerical taxonomy analysis was performed through a data matrix formed by 15 characters. Results indicate an important speciation process of the Ginkgoales during the Jurassic in the southeast of Mexico. New evidence suggests the existence of eight species from the Ginkgoidium Yokoyama, 1889 and Sphenobaiera (Florin) Harris and Millington, 1974 genera and two new species Ginkgoidium nundichii Velasco-de León,

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“…Hypostomatic ginkgophyte leaves are represented by a Sphenobaiera species from the Triassic Molteno Formation in South Africa [[ 23 ], p. 133] and by Baiera cf. furcata from the Middle Jurassic of China [ 29 ]. From the Jurassic Yorkshire Flora [ 21 ] Sphenobaiera ophioglossum shows similar cuticle structures (cell types of costal and intercostal fields, stomatal complexes, presence of papillae) [[ 21 ], figure 17 D], but is designated as the adaxial cuticle.…”

Section: Discussionmentioning

confidence: 99%

Permian ginkgophyte fossils from the Dolomites resemble extant O-ha-tsuki aberrant leaf-like fructifications of Ginkgo biloba L

Fischer

Meller²,

Kustatscher³

et al. 2010

BMC Evol Biol

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BackgroundStructural elucidation and analysis of fructifications of plants is fundamental for understanding their evolution. In case of Ginkgo biloba, attention was drawn by Fujii in 1896 to aberrant fructifications of Ginkgo biloba whose seeds are attached to leaves, called O-ha-tsuki in Japan. This well-known phenomenon was now interpreted by Fujii as being homologous to ancestral sporophylls. The common fructification of Ginkgo biloba consists of 1-2 (rarely more) ovules on a dichotomously divided stalk, the ovules on top of short stalklets, with collars supporting the ovules. There is essentially no disagreement that either the whole stalk with its stalklets, collars and ovules is homologous to a sporophyll, or, alternatively, just one stalklet, collar and ovule each correspond to a sporophyll. For the transition of an ancestral sporophyll resembling extant O-ha-tsuki aberrant leaves into the common fructification with stalklet/collar/ovule, evolutionary reduction of the leaf lamina of such ancestral sporophylls has to be assumed. Furthermore, such ancestral sporophylls would be expected in the fossil record of ginkgophytes.ResultsFrom the Upper Permian of the Bletterbach gorge (Dolomites, South Tyrol, Italy) ginkgophyte leaves of the genus Sphenobaiera were discovered. Among several specimens, one shows putatively attached seeds, while other specimens, depending on their state of preservation, show seeds in positions strongly suggesting such attachment. Morphology and results of a cuticular analysis are in agreement with an affiliation of the fossil to the ginkgophytes and the cuticle of the seed is comparable to that of Triassic and Jurassic ones and to those of extant Ginkgo biloba. The Sphenobaiera leaves with putatively attached seeds closely resemble seed-bearing O-ha-tsuki leaves of extant Ginkgo biloba. This leads to the hypothesis that, at least for some groups of ginkgophytes represented by extant Ginkgo biloba, such sporophylls represent the ancestral state of fructifications.ConclusionsSome evidence is provided for the existence of ancestral laminar ginkgophyte sporophylls. Homology of the newly found fossil ginkgophyte fructifications with the aberrant O-ha-tsuki fructifications of Ginkgo biloba is proposed. This would support the interpretation of the apical part of the common Ginkgo biloba fructification (stalklet/collar/ovule) as a sporophyll with reduced leaf lamina.

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Ginkgoalean ovulate organs and seeds associated with Baiera furcata-type leaves from the Middle Jurassic of Qinghai Province, China

Cited by 24 publications

References 7 publications

Structure of corystospermaceous ovules from the Upper Triassic of Zimbabwe

Structure of corystospermaceous ovules from the Upper Triassic of Zimbabwe

Two new species of Ginkgoales from the Middle Jurassic of Mexico

Permian ginkgophyte fossils from the Dolomites resemble extant O-ha-tsuki aberrant leaf-like fructifications of Ginkgo biloba L

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